Racing suspension is here!!!!!!!!!!

[TomGolden]

Good morning Mr. Kroeker,



First of all, as so many have already said, I sincerely want to thank you and everyone at T-Rex Engineering for bringing to the market such an absolutely outstanding product as your suspension system for our trucks. I would also like to personally thank and commend you for not just your time and willingness to post so much information on our forums here, but the fact that you do go into such fine details about how your product works, how the OEM suspension parts all function, why you feel some of the OEM parts should be retained in a T-Rex equipped truck rather than marketing a zillion piece suspension system and telling the world that's the only way to go.



I am a computer engineer, and I am a very detail and technically oriented person. I sincerely appreciate you explaining things in such detail to us all, rather than some canned responses such as "Just buy our product, it's been tested, it's the best, you don't need to know about all the underlying details anyway, blah blah blah... ". I like to feel that I have a reasonable grasp of the technical details of what I'm getting into, so I can make truly informed decisions about what is the best way to spend my money and what I can expect to receive for it. Also, to know if a particular product is in fact going to really benefit my needs and how I use my truck.



Ok, now to my truck. I currently have the Skyjacker 2 1/2" lift kit on my truck. It includes the D25 coils, all 4 fully adjustable control arms - each with a heim joint at each end. I also have a DT track bar on the truck. I got the lift kit primarily so the truck would be basically level after I installed my Denver Off Road aluminum front bumper and a Warn 12K or 15K winch. The bumper weight ~150 pounds, so with a winch, I will have added an additional 300 - 350 pounds to the front of my truck. I have the bumper, but not yet the winch.



I wanted the control arms, with the heim joints, because it was my perception that these would allow for better flexing of the suspension when I am driving off road versus the OEM control arms. This may in fact not really be true, or it may even be dead wrong...



I do 90% of my driving on pavement, but a few times a year I go hunting or other off road driving. I'm not likely to do anything as aggressive as Baja very often, but hunting roads are often fairly rough, although I am usually not going extremely fast on them.



Now for my questions. I currently have the OEM 16x8" aluminum wheels and OEM Michelin M/S tires. Someday, when these tires ever wear out... I would like to go with a taller tire, something in the 35 to maybe 37" height. I don't really want to go to a 16. 5, 17 or 18" wheel for reasons I'll explain in a moment, so I know tires that will fit on an 8" wide wheel and be that tall are not too common. If I decide to go with different a wheel size, I am very interested in going to one of the 19. 5" wheels that are a direct bolt on option for our trucks, such as the Rickson or Alcoa wheels. Again, I would prefer to go with a 35" tall tire. I am considering the 19. 5" wheels, because the commercial tires I would then be purchasing would basically last "forever" on my truck as opposed to Light Truck type tires. Not to mention the increased load rating and increased stability.



I know your project truck has or has had 37" tall tires on it, so obviously that height of a tire is not a problem for the T-Rex suspension. What would your opinion of a 35" tall tire on a 19. 5" wheel be on a T-Rex equipped truck? These are 7. 5" wide wheels, and I am told this tire/wheel combo will weigh in the 160 pound range.



Next question: I would like to keep my heim jointed control arms with the T-Rex suspension. Even if they don't really add much if any added functionality over the OEM arms, do you feel they would actually be a worse choice than the OEM arms with the T-Rex suspension? My feeling is, even if they don't actually add much simply because they are heim jointed, at least the arms and heim joints will hopefully last much longer than the OEM arms and bushings... hopefully.



This is probably a very obvious question, but can I bring my truck in to your facility near San Diego and have the T-Rex suspension installed on my truck? Don't want to make any assumptions and end up hosed...



Final question, I promise (for this post at least ) In one of your most recent posts here, you talk a lot about track bars, how they function and the DT bar specifically. Since I already have one, I would of course prefer to keep it. I adjusted it so the front axle "appears" to be centered while the truck is sitting motionless, which according to your post is most likely not the best situation. Could your folks properly adjust it during installation of the T-Rex suspension as well?



Again, thanks a ton for your information and great product development.



Warmest regards,

Tom

 

[Clinton]

I meant savvy in the perceptive and knowledgeable sense not necessarily shrewd, but at $3500 a truck, I expect you're shrewd as well.



Now then, thanks for the DT trac bar discussion. That makes perfect sense and although I never bottom the axle on the bump stop I'll have to look into centering per your advise. Don't know when I'll have it broke down that far again, but I'll check it out when I do.



I'd like to know if you're familiar with the condition of caster shimmy, often referred to as death wobble here on the TDR? Has the T-Rex test mule ever shown any signs of this dreaded curse? Seems many members have had it at one time or another and some actually have to live with it. I've had it due to bald tires (I think). I have a vague understanding of the condition and was wondering what your take on it is and if the T-Rex system would address it or any of it's potential components. Thanks again.

 

[kscheffler]

Kent

Does the TREX system help the Dodge trucks on ice?? As most Dodge owners should have experienced how terrible our trucks are on icy roads without a heavy bed load the rear end tends to break free on expansion joints. Based on your previous discussions it appears that your system should help us "ice drivers" . Your comments on this would be appreciated... kts

 

[Doubleclutch]

Will T-Rex be at DEPO in Oct.?

TTT

 

[kentkroeker]

Gentlemen,



Sorry for the slow response to your questions. We were in Baja all weekend. Monday has been dedicated catching up and shipping product.



Meeting and corresponding with TDR members is becoming my favorite thing to do (besides driving off-road!), so I've been looking forward to getting back on line for some time now.



Mr. Golden,



Thanks for your support of our philosophy. When we were starting to form this business several years ago we decided to focus on becoming the very best at only one thing instead of trying to generalize. We no longer do anything other than Dodge solid axle high-performance suspension, so I take great pride and a lot of pleasure explaining what we've learned. The smallest details of our product have been refined from much experimentation and destruction. It would take years for even a large company with massive resources to catch up to what we've learned. Example: Two days ago we were testing rear leaf configuration number six. Several elements of the leaf design turned out to be incorrect, causing the rear facing shock to blow completely off the frame! I could, if pressed, write an entire dissertation on why this happened - a forward shock angled 27 degrees, a rearward facing shock angled at 22 degrees (the factory does this intentionally), shackle swing, axle displacement, torsional flexing during certain events, non-standard bump stop compression, heat-related metal fatigue, OE weld penetration - on and on and I love it! Yesterday we took the bed off the truck, performed a sort of forensic analysis, re-fabricated a new mount in the OE location and discussed the flaws in our leaf pack. The leaf pack on the 2003 Ram also performs as an anti-sway bar, so you can imagine the task we have designing a leaf pack that can improve on OE! I'm currently working with who I think is the Nation's top spring designer. We should have a new pack for testing in two days. I think what I'm trying to say is that we're a business and selling suspension pays my mortgage, but, unlike a big impersonal corporation, T. Rex Engineering is passionate about what we do. Basically, we think it's fun. That's why I enjoy sharing this information on TDR. Thanks for the kind words.



O. K. Your questions



Q: What about the 19. 5" wheel with a 35" diameter tire?



A: In Mexico you can buy a Dodge 4500 - a big, ugly stake-bed that comes stock with 19. 5's on it. There is a reason for this large diameter wheel and commercial tire - load bearing and longevity. We have never used a "commercial" setup because we believe they should be used on "commercial" vehicles - like vehicles that deliver milk, bread, or King shocks. We just like to go fast off-road. And to do that, you need a certain setup. "Commercial" tire/wheel combos are for saving companies money. Do you think companies care more about the comfort of their drivers or their safety record and minimizing service costs? I'm relatively new with TDR, so I'm just starting to understand member trends from an "outsiders" perspective. I know that Rickson offers these wheels as a direct bolt on. I think that the appeal to TDR members comes from the heavy duty aspect of the wheel - the idea that you can buy a tire that will last a LONG time - over 100k miles for instance. That's good when you have a Cummins engine that also lasts a LONG time. Just remember - that wheel and tire were made to carry heavier loads than what your truck was designed for - and mostly in one situation - highway, pavement or, at worst, improved secondary roads. Unless your truck is loaded way down - to the point that the frame and suspension components would be at or near their max GVWR, your truck will drive and ride much more stiffly than with a light truck tire on your OE wheels - even a good D or E rated tire. Your tires are your first line of "suspension. " The springs and foam in your seats, the last. Pump up the tires you currently run with about 150 psi and you can simulate the ride a commercial tire will give your truck. Even if you run a 35, your aspect ratio would be so low that you would not have enough air between the wheel and the ground to provide a reasonable cushioning effect during on or off-road impacts. We have never experimented with 19. 5" wheels [or 20" chrome wheels with spinning inserts, for that matter! hahaha] but I've spoken with several people who have. All of them conclude that the ride is intolerably harsh - even at or near max GVWR. Would you buy a pair of shoes made from solid wood because someone told you they would last a long time? Maybe if you're Dutch, but tires, like shoes, are made to wear out and feel a certain way while they wear. They're made from _sacrificial_ materials. They're made to wear out and protect other components while they do - just like the oil in your crank case. So, like shoes, you buy something that fits correctly and feels good, then you replace it when it's time. And nobody would ever use a 19. 5" wheel for racing or even semi-serious off-road - aspect ratio, unsprung weight, width all being wrong... Wait a minute... I have to get into your head like a detective getting into the head of Hannibal Lector - I think you already know how bad those shoes will feel on your truck; what you're really asking is, "Will T. Rex suspension be good enough to make a problematic, commercial wheel/tire combo feel smooth on the road so I can have the best of all possible worlds - an indestructible suspension system and an indestructible wheel/tire combo that offers my wife a smooth ride? If it's possible, my wife will Ok the purchase because it will actually _save_ money in the long run because the entire gig is a one-time, no-further-maintenance-required purchase... " Well, I would like to tell you, "Yes, Mr. Golden, our T. Rex suspension will make those harsh tires feel buttery smooth. " But I won't, because that's not true. I think our suspension could make commercial tires feel _better_ than OE suspension, but not enough to make wives happy with the commercial rubber. Sorry. Our suspension has been tuned for normal light truck tires - from 31's to 37's, the tires that will work best on your truck in all situations. We could, theoretically, experiment and valve shocks specifically for use with commercial tires, but the ride quality would never be as good as the ride you would have with tires and wheels designed to fit your truck. I like the way you're thinking though!



More to follow tomorrow.

 

[GWHaley]

Mr. Kroeker

I don't know if I like reading your updates more or if you like writing them more, but keep it up!!!! You have sold me---I just need to save my pennies!

 

[TomGolden]

Kent,



Thank you very much sir, for more detailed, clearly understandable explanations. I sincerely appreciate your answer to my concern regarding the 19. 5" wheel/tire issue with the T-Rex suspension. From other threads on the TDR where I have asked about the commercial wheels/tires and high speeds, opff roading, etc. , I have received responses that concur with your statements about the commercial tires basically being suited for pavement (and not for overly high speeds), and a rather poor choice for off road applications.



I tend to look at my truck as the ultimate utility vehicle, I want it to be capable of everything, not just anything. A bit unrealistic? yes, I know it is, if for no other reason than I don't have nearly enough money to do every thing I would like to. If I were to do everything I "think" would improve the logevity, capabilities and performance of my truck, I'd end up driving around in an M1 Abrahms tank! The truck would be able to drive anywhere, over any terrain, would never wear out, but would be soooo heavy, bulky and slow, it would be effectively no more fun to drive, and as I'm sure you'd agree, where's the fun in that



I also did the math, and used my current wear rate on my OEM tires to extrapolate how long I would have to drive this truck in order for the cost of the 19. 5" wheels and tires to be really cost effective, and the number was quite surprising, on the order of 350,000 miles, and that was just the point at which the 19. 5"s would have equalled the cost of continually buying 16" LT tires. So, that idea may have ceased to be as appealing as it seemed to be.



So, back to suspensions. I'm sure you needed to catch at least a couple minutes of sleep after a long and productive weekend in Baja, and please take all the time you need. I am still curious about your feelings on keeping both my DT track bar as well as my heim jointed control arms with the T-Rex suspension.



Thank you again, you are a very welcome addition to the already outstanding collection of product vendors who are TDR members



Tom

 

[Dr.Kayak]

Kent, I would love to hear if it is possible to engineer a less expensive solution. I know my Rancho 9000s are, at best, a slight improvement over stock. Is there no middle ground between stock and a full blown racing suspension?



I am also having trouble understanding how an empty ¾ ton truck could ever ride as smooth off road as you describe. My rear end bounces off the ground at moderate speeds when off road. It can help but think it’s mostly due to the stiff leaf springs.



Thanks for all the great info.

 

[kentkroeker]

Mr. Golden,



Thanks for doing that cost analysis! That's just the kind of thing I always tell myself I need to do, but never end up doing. Empirical data is hard to beat!



By the way I must add a caveat to the last post:



T. Rex Engineering is not criticizing the excellent products that Rickson sells. We are just expressing our opinion. For some applications the 19. 5" wheel and commercial tire combo is probably an excellent choice - for increasing safety, stability and longevity while towing a very heavy fifth wheel trailer for 100,000 miles per year for example - such as for a business.



Ok - on to the rest of your questions.



Q: How about my heim-jointed control arms?



A: This one is kind of involved! Friday morning, before heading to Baja we had a photo shoot with "Four Wheeler" magazine. We met at "Plaster City" near Ocotillo, CA, just north of the Calexico/Mexicali border. When we arrived we found that the T. Rex project truck was not the star of the show! The main act was Craig Stewart's (Ivan's son) unbelievable $250,000, hand made Class 1 (SCORE) race car. Talk about a radical beast! I saw the thing do 140 mph over four foot deep sand whoops, then jump ten feet in the air. Kind of made the T. Rex truck look wimpy! haha! Anyway, that "truggy" (it's called a truggy because of its configuration) had King shocks at all four corners and every moving chassis component was attached with spherical bearings, aka "heim" joints. Some of the heims were as big as your fist! They are the _only_ way to make a vehicle's chassis perform at this level. Heims are good, expensive parts that last a long time. Besides their durability, the advantage (and disadvantage in street applications - as I'll soon explain) to heims is that when they articulate toward their max angle, they don't compress like rubber.



We'll use your control arms for an example. Your control arms move up and down freely on their bushings. They also move laterally as the track bar pushes them back and forth while your axle moves up and down. For pure off-road, heims are an excellent choice for control arms because they #1 increase free articulation (the angles to which the suspension can move without hindrance) and #2 reduce friction by not becoming more taut the way rubber does as you compress it. These factors result in greater durability and a faster-reacting suspension that provides a very supple feel off road. All good things.



Two years ago we installed our own hand-made, adjustable control arms on a couple of very, very custom Dodge Rams we set up. The first we did in order to replace the stockers because they bent too easily when we pressed the truck off-road (this is after we cut off the front spring buckets and installed full coil-overs providing roughly 11 inches of travel and installed tubular shock mounts in the rear providing 13 inches!). We replaced another Ram's control arms in order to provide enough fore/aft adjustment to allow the truck to align properly - its frame was tweaked.



Here's what we learned:



When you drive a car in Baja, you've got both hands on the wheel, only removing one momentarily to shift. Your eyes have what racers call a "scan pattern. " You look out as far as you can see, then look in close, then repeat the pattern, pausing for a fraction of a second longer on the medium distance - because that's where you're going to be in a heartbeat. When you're really driving off road, you're INVOLVED with the vehicle and the terrain. Your hands are moving the steering wheel quickly acting and reacting constantly. This is where heims work great - when you're involved.



What about when you just want to load up the truck and cruise to Vegas for the weekend? Craig Stewart's race car is impressive but it cannot be driven with one hand on the wheel and a Big Gulp in the other. Nor can any of the trucks we've set up that use heim joints on the control arms. The owners don't care because they drive primarily off road - the place where heim joints shine - where you're involved with the vehicle and the terrain _anyway_. Heim jointed control arms on a street truck do not work as well as rubber bushings because as they articulate toward their max angle they don't provide any resistance to push them back toward center. This forces the driver to make constant corrections while on the highway. Fatiguing and annoying. When we've made control arms we've used the best bearings available - pure stainless made by "Aurora. " I've seen some cheap stuff floating around out there - heims made in China for example. These heims start making noise early on - starting with a "rattle," then eventually a "clunk. " No matter what spherical bearing is used, every Baja race car makes heim noise from its chassis - squeaking, rattling, clanking - they have to because hiems are a metal to metal+teflon bearing and require certain clearances so they don't seize. Shock heims do not make noise because the nitrogen pressure on the shock keeps positive energy on the bearing at all times, eliminating clatter - even after thousands of miles.



Another benefit rubber provides is simple impact isolation. A heim joint provides zero impact isolation. At the ends of a shock absorber, this is no problem, the shock is isolating the hiem. At the ends of your control arms, the elimination of a rubber bushing can cause problems. Before impact force can get to your control arms, it has to go through your tire, so some event energy is absorbed, but the shock can't help your control arms much because it's straight up and down and your control arms are more horizontal. The biggest problem is that the control arms, the axle, wheels and tires and everything under the shock is known as "unsprung weight. " This is weight that can't be controlled with suspension. It's just dead weight, so when it hits a bump, the heavier it is, the less it wants start moving - and once it starts moving, the less it wants to stop - Newton. So, imagine 7000lbs of truck repeatedly smashing into 500 lbs of dead weight under your truck - and much of that energy focused on eight points - the ends of your control arms. Now that you've replaced your rubber bushings with heims, they don't compress fore and aft, they just release energy into your control arm mounts. This is no problem on Craig Stewart's race car. Every mount is engineered to withstand the tremendous stress that his chassis heims can impose. This _is_ a problem on your truck because your control arm mounts were designed to use rubber bushings, not heims. When we switched to heim-jointed control arms we started breaking mounts - the bottom ones first. So we re-engineered the mounts, making them much stronger.



We haven't tested it, but we even believe that without control arm mount reinforcement, urethane bushings won't provide enough cushion and that rubber is still the best.



Anyway, the point is that for general use - we feel that rubber bushings on the OE control arms is the best option - from both a performance (street and off-road) and reliability standpoint. An adjustable lower arm would be nice and we may offer this one day just to true out trucks that are bent, but for now we like OE.



Once again, let me throw this in: Your results may differ. You may have heim jointed control arms on your truck and they may work fine for your purposes. Your truck may not rattle and squeak while it wanders sideways down the highway; so when it comes to your personal vehicle I may not have a clue. I haven't driven your truck, nor seen your control arms and your setup, so I can't really speak with conviction about your truck's performance. I'm just relating T. Rex Engineering's experience with similar designs.



More to follow.

 

[kentkroeker]

Q: Can T. Rex install my suspension system and center my track bar at the same time?



A: We are currently overwhelmed with production and distribution, so we're getting away from installation. We have confidence in several So Cal shops that have experience with our product. They know about the track bar issue. We would be glad to refer you to them. But don't hesitate to call us. We may be able to get out of the office for a couple of hours to set up your truck.



Mr. Clinton,



Q: Has T. Rex experienced conditions such as "caster shimmy" or "death wobble?"



A: I can't really say our project truck exhibits any negative handling characteristics. When set up properly it's really neutral in the turns and tracks straight - even after being hammered for many thousands of miles off road. I've driven earlier models that wobble and wander all over - but I think this is related to the track bar design. "Caster shimmy" would lead me to believe there may be play in the king pins (the location of the angle known as caster). "Death wobble" I've experienced many times. It comes from accidentally landing sideways from an 80mph jump. You have to stop and apologize to your passengers, then go slow for at least 30 minutes while everyone calms down. This phenomenon is a result of "operator error" and has nothing to do with the vehicle! I know this isn't the "death wobble" you TDR guys are talking about, I'm just kidding around a bit.



Mr. Scheffler



Q: Does T. Rex suspension help with ice?



A: We did a lot of cold weather testing in the mountains. Our concern was not with performance, but with reliability. The shocks were designed to work well in hot, Southwest racing conditions, so we didn't know if we could confidently market them nationally. Several times we took them down to 0 degrees Fahrenheit, then immediately went and smashed the tires into hard objects at high speed - to see if we could blow the shock seals. We couldn't. The truck handles well in snow without chains - it's just plain fun to drive. But I can't say that our suspension (or any suspension for that matter) can help handling on ice. I think that proper ice handling is more of a product of tire traction than suspension articulation. Now, if you're driving over bumpy, icy roads, good suspension can help because the goal of all suspension is to keep even traction on the ground at all times. Our suspension does this better than any suspension currently on the market, so in that respect it may help. But I can't confidently say that it would be worth the money just to drive on ice. When I drive on ice I always feel traction limited and not suspension limited - but I'm a wimpy Californian who feels much more at home on dirt than ice!



Doubleclutch,



Depo in October? I don't know what this is. If it's a TDR rally of some kind we will do our best to be there with systems to sell and a truck to demo. Please explain, so we can start making plans early on.



Dr. Kayak,



Q: How about a less expensive system that still offers great performance?



A: We are working on exactly what you want. Our biggest problem is that people just don't have a clue what it is we offer. We change the truck so dramatically that it's like owning a completely different vehicle. It makes it really, really fun to drive off-road. But not everyone wants to spend $3,500. 00 to get there. Prior to focusing just on the Dodge Ram, we (and many other companies) did fully custom suspension systems costing $15,000 - and the performance was _half_ what we offer with this bolt-on system. We made it work by struggling for a tiny fraction of performance again and again until it worked better for a fifth of the cost. Most people who experience a T. Rex system think it's a bargain. However, we know that some people just don't need that much performance, so we're trying to develop a system that gives about 50% of the performance for a little over half the cost. Now you may think, "what - 50% of the performance of the racing-inspired system! That sucks!" Well, 50% is still 100% better than your Ranchos, so stay tuned. We're developing this one with a target price - expect it to retail for around $2000. 00. It should be on the market in about a year.

 

[duaneparks]

"Death wobble" I've experienced many times. ... This phenomenon is a result of "operator error" and has nothing to do with the vehicle!







Whoa K, you might ruffle a few feathers with that comment, but keep typing... I'm learning a TON about these suspensions.



From what I've read on here, the "death wobble" can occur on a road that the driver has driven countless times, it's just *that* particular time, when it occurs, everything that's worn works against each other and causes it. For instance, Driver X heads to work the same way he always does. For some reason, on this day in question, he hits the same expansion joint/pothole/pavement ripple at his normal speed (usually at or near highway speed) and his truck becomes uncontrollable. I had a friend with this problem, ended up that his caster was way out. Others have found that a worn track bar or ball joint caused the phenomenon, among other culprits.



Now in the case you describe, yes, it may be operator error, but I bet you had a blast right up until then!



Duane

 

[kentkroeker]

Duane,



The last thing I want to do is ruffle feathers! I was trying to express my ignorance toward certain phenomena by making a little joke. I was in no way insinuating that "death wobble" was a result of someone's improper driving technique! haha! I was talking about _my_ often sloppy off-road "operator error" - like when I had a group of TDR folks in the project truck and they said, "hey, Kent, watch out for that rock!" I said, "it's OK, I see it... " Well, I was looking at a different rock than they were. They saw the 20" boulder that exploded the steering stabilizer and tore the reservoir off the passenger side shock! hahaha! That's what I mean by "operator error. " What I should have called it in the last post was "Kroeker error!"



There's a lot of TDR specific lingo that I'm just starting to learn about - such as "death-wobble" and "caster shimmy. " Until recently I didn't even know that you TDR guys were calling the Dodge snowplow springs "D25. " Thanks for your description of what seems to cause "death wobble. " I'm learning a heck of a lot from you gentlemen as well!



Best Regards,



Kent Kroeker

T. Rex Engineering

 

[Doubleclutch]

DEPO

Kent- The DEPO show is not listed in the TDR magazine this year. The show will have the same basic content as in the past, but will be all on one day, Saturday October 11. Sled pulls, dirt drags, vendor displays and seminars, etc.

The contact is Leonard Sanchez at -- email address removed -- There is an active thread called "Tulare" that might be worth looking at. This is probably the largest CA get together of TDR, with the Ford and Chevy guys also attending. With all the "ink" you're getting, better bring a couple of set-ups!

Greg

 

[Cooker]

Originally posted by kentkroeker

Until recently I didn't even know that you TDR guys were calling the Dodge snowplow springs "D25. "

FYI - Most times the D25 Springs are mentioned we are referring to the Skyjacker 2. 5" Lift or more commonly referred to as Leveling Springs (Since most feel the trucks sits level after installing the D25's).



I think the reason some may feel they are snowplow spings (and to be quite honest I have never seen them referred to as such, darn it I must have missed a post somewhere ) is perhpaps the added height offsets the drop of the nose with the plow on returning the front end to approx. stock height (with the weight of the plow).



Thanks for all your feedback.

 

[duaneparks]

Originally posted by kentkroeker

Duane,



The last thing I want to do is ruffle feathers! I was trying to express my ignorance toward certain phenomena by making a little joke. I was in no way insinuating that "death wobble" was a result of someone's improper driving technique! haha!

No prob Kent... I was mainly joking with you. You keep on talking suspensions. This thread is GREAT!



Sounds like your suspension is kick-a$$ and worth the money due to all the R&D (fun?) and quality products you've put into it.



Even though I'm not in the market for suspension upgrades right this second, I will be in the not-too-distant future, and I will refer back to this and future threads on your product. Keep up the good work!



Duane

 

[TomGolden]

Kent,



As Cooker just clarified, the D25 are Skyjacker's replacement coil springs that add ~2 1/2" of front end lift. Those are the ones I have, as part of my 2 1/2" Lift Kit from Skyjacker.



Once again, I really want to thank you for your extremely detailed description of control arms, and the differences between rubber vs heim jointed arms.



There were really two reasons I wanted the Skyjacker arms: 1) I thought the heim joints would give better suspension articulation and would last longer than the OEM rubber bushings. You have basically concurred, that in an off-road situation, heims are the better choice for allowing greater articulation. 2) The Skyjacker arms I have are round tubular arms, as opposed to the traingular-3-sided OEM arms, and I thought the actual body of the arms would be stronger than the OEM design, but I could be mistaken here as well.



Actually, just driving on pavement, I have thankfully never had any real steering/wander/death wobble or other steering or suspension problems with my truck. As with many of the modifications I have done or plan to do, they are more for improving functionality and strength of my truck, rather than to fix something that has or is about to fail.



Another question for you then: I can certain understand and appreciate that your shop is swamped with R&D and other activities and may not always have time to do installs. That's actually good for you, as product development is where your financial future lies, as basically any competent shop can be trained to do installations. So, since I live up north near Sacramento, are you currently aware of or have any relationships with shops up north where I might have the T-Rex system installed, should I decide to do so



Thanks as always,

Tom

 

[kentkroeker]

Mr. Golden,



I'm glad your control arms work well! Their construction sounds much stronger than OE (on race cars almost everything is tubular), so you should be good - especially if you're not experiencing any steering wander - which leads me to believe that the company that made them used high-quality spherical bearings.



Because your real-world experience has been positive, if you purchase our system, I suggest you retain your control arms. Just keep an eye on the lower frame mounts. And remember, during our R and D we impose much, much more stress on parts than most people ever will. We're going far beyond what is even considered to be normal off-road use, so I concur with your assumption that your control arms should last a long time and work well. And, because of the reduction in friction, they will definitely make our system feel better when you use your truck off road.



At this point there are very few installers in whom I have absolute confidence. Frankly, I don't think that the installation of our system is that difficult, but I see little errors all the time - such as not providing enough clearance for reservoir hoses or not protecting them properly - also not making sure the driver's side rear shock clears the spare tire. These are BIG shocks, so if someone is using an oversized spare, the reservoirs can rub the tire as the axle moves up toward the very bottom of its travel. In this case it's really important to relocate the spare. A good installer knows to look for these things because he's read our instructions and won't make any errors. I would never recommend you take your truck to the big retailers to have an installation. Not only do they not have proper equipment to charge shocks with nitrogen, but they are more interested in just getting the job done quickly instead of properly. I've seen really slipshod work done at these shops - such as stretching components with jacks and pry bars to remove or install springs etc. We currently don't have anyone we trust in Sacramento, but nearby, in San Jose there is an excellent installer who has experience with our system and shares our commitment to quality and attention to detail. The name of the shop is "Rockstar Trux" and the owner is Mike Jiminez. Their number is 408. 295. 5055. They are small, but very cutting edge and Mike is a real professional who understands modern shock technology. You may want to call him and ask what he thinks about the T. Rex system from an installer's standpoint. I can also speak to him about your track bar and have him center it the way I described in previous posts.



Gents,



Thanks for the clarification on the D25 springs!



Best Regards,



Kent Kroeker

 

[TomGolden]

Kent, I'll see if I can take a good digital picture of my control arms, maybe with a measuring tape to show their diameter and post it so you can see them, just for the heck of it. I will also look at the heims to see if the manufacturer name is on them, as I doubt Skyjacker actually made them.



Thank you for the name and contact info for the shop in San Jose. I have found what you said to be very true, about shoddy work at some shops, and I am entirely willing to travel to make sure the work is done correctly the first time. I went to San Jose to have my South Bend clutch installed, and couldn't be happier with the quality of that installation and shop



Now, back to the subject of tires. Spares, to be specific. You mention in your last post that if the spare tire is too large in diameter, it may interfere with the rear shock(s). In your opinion, what would be the largest spare tire that can safely fit in the OEM location? I am still running the OEM 32" Michelin's, but I would eventually like to go to a 35" tall tire. I do not expect to ever go taller than that, at least not at this time. Will a 35" tire be safe in the OEM location, or would it be better to relocate it? For everyday driving, I would not mind relocating the spare, but when I go hunting, or serious off roading, I always like to carry 2 spares, and even the OEM sized tires are large enough that 2 of them in the bed of the truck would eat up way too much valuable room, needed for carrying camping/hunting gear.



Thanks,

Tom

 

[Cooker]

Tom,



I don't think a 35" tall tire will fit in the OEM location with OEM shocks. From my understanding a 285/75/16 (33") is the largest tire that will fit. A worn down 295/75/16 (33. 5") will fit, but if I am not mistaken a new 295 will not fit in the location.

 

[Morphious]

On the spare tire location on my truck, I can barely fit a bald 285x75x16 BFG Mud tire, and by bald, I mean as bald as my head. And even then, it's not easy, I have to use a sledge to beat it on up in there, and it's fun as hell getting it out again.



Kent, I have a question about installation, I'm a do it yourselfer, and if and when I go your route, I'd probably be doing it myself, as I live on the right coast. Are there any special tools or the like needed for a diy job? Course, the way money has been going, will probably be a year or two before I can obtain the setup.



Morph.