'93 Dodge/Allison conversion questions...

[MChalkley]

Ok, yet another Allison/Cummins/Dodge conversion discussion here...



First, a little background: Although I just joined the TDR website after renewing a TDR subscription that I'd let lapse for a year or so, I was a TDR subscriber for years. In fact, my last major conversion a few years back (a 1st-gen NV5600) was written up briefly in TDR. Which leads me to my truck description and what I want to do this time around:



I've got a '93 Dodge W250 Club Cab which I yanked the Getrag out of and shoehorned a NV5600 into. I've got 3. 07 diffs (yeah, I know, but they've worked great for me so far... ), Sachs high performance clutch and pressure plate, BD exhaust brake, higher-hp injectors, wastegated turbo, Banks intercooler, fuel heater, 33x12. 50's, etc. I pull 20-25k regularly (yeah, I know, but I'm not the only one... ).



My problem is this: With the NV5600, I have to use a new body style master cylinder for the clutch, which means I have to buy a new set (since I can't find a place to buy them individually), then take the master cylinder to a machinist to have the rod shortened. Since I've got a stronger pressure plate, my clutch master and slave cylinders are only lasting 20-25k. Needless to say, I'm getting tired of replacing them. Also, the wear and tear on the driveline is a lot worse than it would be with an auto, I'm sure.



What I'd really like to do is go to an Allison (or other suitable STRONG automatic) transmission. I'm not going to put in something that doesn't have a lockup torque converter, and it either needs to be a 4-speed non-overdrive unit, or a 5-speed w/overdrive (preferably, though I wouldn't use the overdrive for my heavy towing, obviously). It also needs to mate to the transfer case, of course.



I talked to ATS and they have their 47RE-based transmissions, but a 4-speed overdrive is one too few gears for the load I'm pulling, I think. They're not going to have an Allison (a highly modified 1000) 5-speed overdrive ready for installation for 8 another months or so (they hope).



With all that said, does anyone have any suggestions for what my possibilities are? I've looked through all the existing threads on Allison conversions. I'd appreciate any info on what would work, what's needed, or even shops that could do it. I'm in Virginia, but I don't mind taking the truck somewhere if that's what I need to do.



Thanks!



Mark

 

[cerberusiam]

Mark, interesting project. What are you pulling thats runs that much weight and is that GCVW?



I have found the Allison conversion to be extremely expensive and not really worth the extra work. I would seriously question the ability of the 1000 series to handle a well setup Cummins even though ATS thinks it can be done. Going to the medium duty Allison is an option but that is where things get expensive and given what you are doing I think it is a waste of $$$ unless you are set on it and want to have a unique truck. The 47RH/RE with all the good parts and good maintenance will provide you with a strong usable unit that won't break the bank. When you start going over the 25k loads there are issues but nothing that can't be handled if you know whats what.



FWIW here is what I think. You don't need 5 gears at your load level. The Cummins has more than enough torque to be usable with 4 gears. Depending on the trans all you get with a 5 speed is a really low 1st gear. Regear your diffs to 4. 10 or better 3. 73. With the 33" tires and a lockup converter you should be about where the Cummins wants to run. If it is a little high you can go to a taller tire to adjust. The 3. 07 are fine for an unloaded rig but not for a tow rig. You are hammering the tar out of the drive train at the low rpm's and proabably unable to use the last gear because it won't pull. Get a trans with a multi-disk converter and use it. With the after-market controllers available you can lockup in any gear. This will give 8 forward gears with a 10 to 15 percent difference in each gear depending on how tight a converter you get. You will have to spend some dollars on billet shafts but it will be worth it. The nice thing is this unit will bolt in with few modifications to your current setup and if you have a break down you stand a chance of finding some help, even in Valentine Nebraska.





My . 02. Good luck.

 

[MChalkley]

Thanks a lot for the info and suggestions. I pull a mini-TLB and attachments.



I've seriously thought about regearing the diffs. I know you're probably right about it not beating up the drivetrain as much. However, right now, in 5th gear (direct), I tach right at 1800 rpm at 55 mph, which is perfect for highway towing, which I do a lot of. Similarly, when I'm running empty on the highway, I tach about the same rpms at 70 mph, which again is perfect.



So, I was hoping I could cushion the drivetrain with an auto, get rid of my clutch problems, and still keep the rest of the benefits of the setup I've got. Maybe I'll end up splitting the difference and putting in 3. 55's...



If I could get a medium duty 5-speed Allison, that would be just the ticket. I expect that to cost fairly big bucks, and I'm prepared to pay for it - since I don't plan on ever letting go of this truck, it would be a reasonable investment, to me. The problem is that I don't know anyone who has a good enough understanding of what's involved, especially with regard to the transfer case compatibility and the electro/mechanical transmission control issues.



I didn't realize the multi-disk converters offered the advantages you mentioned. That's pretty cool. Any recommendations on brands/sources? What about aftermarket controllers?



Thanks again,



Mark

 

[cerberusiam]

Two issues I know of on a medium duty Allison, the starter moves to the right side of engine right where the down pipe is. Not sure if there is a configuration that will put starter on the left side. The second big one is Tcase. That is either a custom tcase and connector or another tcase that is compatoble with trans. I was told the allison shafts are to big for the OEM tcase shafts and that would be a custom mating. I believe a Rockwell tcase will work but big $$$ and mounting. The other thing is the medium duty allison won't fit the trans tunnel so major mods are needed. I quit at that point becuase it was more than I wanted to spend to get a usable truck. I could buy a used medium duty frame and mount the cab on it or just get a newer truck that would work better. I started digging into the OEM trans all the info I found tells me unless I wanted to go up to 30k to 40k the 47RH was a better deal and would perform.



There is a harmonic resonation in the Cummins engine that happens at 2 different rpms. The first is at 1700 to 1900 and the second is around 2300 to 2400. Running constantly at these rpm's has a tendency to just hammer the drive train. Its better with a non-lockup converter but that is worthless. An auto will absorb more than the manual but you can shake an auto to death also. My best guess for optimum rpm would be 2000 to 2100. That seems to be the sweet spot for power and efficiency but it can change depending on engine and CPL.



The 3. 55 is great all around ratio but on the heavier weights it lacks a little. Its entirely usable but you can run into EGT problems if your pushing enough fuel. I would much rather run a little too much rpm than too little for safety sake but thats a personal choice. The 3. 73 is just about perfect for every thing hence thats what the gen 3's are. The 4. 10 is usable with tall tires and may be easier to find. You could probably trade your 3. 07 diffs straight for what you want as they are in demand. I just don't like putting that much stress on a drive line that is marginal at higher power levels hence I don't like the taller gears or any kind of aux gear box. Thats just my view and may or may not be right from your point of view.



Call Dave Goerand at Goerand Brothers Transmissions and tell him what you are doing and what he thinks. I would call ATS and DTT as well and get their input for your scenario then make your decision. Good luck.

 

[MChalkley]

Ok - now you're trying to discourage me with facts. ;>)



You bring up some very interesting and important factors concerning the resonances. I've noticed them and have no doubt that they've contributed to the problems I've had. Ok, so maybe I need to change the diff ratios...



I guess I'll talk to ATS again about their beefed up 47's. I still don't like the idea of the 4-speed overdrive, but I guess everyone else is using it, so it oughta work for me. Sure wish it was easy and cheap to do what I want (not for the first time, either).



Thanks again,



Mark

 

["Mad Max"]

Mark -

I was going through your thought process about 6 months ago. What I found out was that an Allison, though a good transmission, would need to be a 3000 series in order to handle a modified Cummins, and after the (no kidding) $10,000 price tag and sheer dimensions (they're HUGE) of the Allison I decided to do a fully rebuilt upgrade to a 47RE. DTT (one among many possibilities) is going to build my transmission. I think the cost of a good 47RE/H would be better mony spent verses an Allison.

As well, a gear upgrade would certainly help get things moving, and the lockup converter conversion would keep things moving. Of course you'd need to do gears on both ends which is a little more $, but I still think, in the end, well worth it. Depending on how hard you want to pull would dictate which upgrades are done to the transmission. In my case I'm looking to pull, at the worst case, around 20,000 lbs gross, including the rig/trailer/load, so I'm doing 4:10's, a 47RE, and a GearVendor od to maintain top speed without spinning rpm's unnecessarily.

If you go lock-up, either an RE or RH will work, as they use their own valve body which is a hydraulic unit. Essentially the electronic guts are replaced with hydraulic ones, and the lock-up and od are governed by a separate controller, included with most conversion and upgrades to the transmission.

- Sam

 

[cerberusiam]

Heavens!! I would never want to discourage you from something you really wanted.



Just trying to offer an alternative that leaves $$ for other toys.



Sam and I have both been down this road and it just flat gets expensive when you start talking Allison conversion.



While your talking to ATS have them give you a run down on the Strategy Controller they market. It is one of the more full featured products out there and should work for what you want.



Good luck.

 

[MChalkley]

Ok guys, you've got me moving in the 47RE/H direction now. I talked with ATS again, and they're working up some numbers for me. I ran the numbers a while ago and, with the 33x12. 5 tires and the higher . 69 od in the auto, I think I could live with the 3. 73 rears, too.



Unless I can come up with somebody on the east coast that knows how to do this stuff, it's beginning to look like I'm going to be driving from Virginia to Colorado in a '93 Dodge with a clutch that won't disengage. While that's not something I look forward to, I'm not going to let anybody that doesn't know what they're doing mess with it, either.



Is the Strategy Controller the same one that ATS' website calls the TripleLock Controller?



Thanks,



Mark

 

[cerberusiam]

The Triplelock controller is for the converter only. The Strategy Controller did a lot more but it is not listed anymore. You may only need the triple lock controller depending on what you want to do.



Good luck.

 

["Mad Max"]

. . and the DTT unit is called a Smart Controller. Also, most of the controllers can be tailored to fit the needs/wants of the owner based on their driving habits, so what is advertised can almost always be tailored to how you want the system to work. Ask the sales/tech reps about that and they'll steer you straight. In my case, I wanted the system to be both fully automatic and fully manual, based on the circumstances and my preferance for control, all via a simple toggle switch. So, when the system is in automatic mode the converter will lock up at about 35 mph (once the rig is moving) and the od will hit at about 55 mph. That'll be the majority of my driving style so I want it to be like that most of the time. But, when I'm hauling up a big honkin hill or worse going down a big honkin hill, I want to dictate when the exhaust brake hits and which gear I'm in based on the speed I'm going and how steep everything is, so I want to be able to go manual, disengage the GV od, leave the factory od engaged, hit the ex-brake, and leave the converter engaged all the way to almost a stop. Essentially, use the gears to slow down and the brakes to stop. The Exhaust brake is a big reason I'm going to a lock-up converter system - the heat reduction and mass-moving is the other.

- S

 

[AKAMAC]

cjohnson1 did a conversion on his motorhome. Search his name under the conversions fourms. He had problems with the ratio too. Heres one... ...



http://www.tdr1.com/forums/showthread.php?t=82393

 

[Wayno]

There was a member here in Texas that did it a few years back but I cant remember his name . He did it in a sec. gen. He bought a old street sweeper at a city auction and he had every thing he needed to do it but he did put a gear vender behind it . He ran hot shot with the truck . I saw him at a LSTDR meeting down in Wharton . You mike ask Bill Linns here on the forms he is from that area and he might know who he is .

 

[gbm]

MChalkley,

If you are determined to put an auto into your truck, I wish you the best of luck. Please keep us informed on your progress, and how it works out for you.

I have done the same only reverse – on my last truck. After having several automatic transmissions – rebuilt, aftermarket rebuilt, “last trans and torque converter you will ever need” built… I still had problems. (My last truck was a Chevy with a TH400, I also tried built 700’s)

My solution was to install a manual transmission. I installed a HD 5speed with a direct 5th gear. I Installed a Ranger 2 speed also. This gave me 10 forward gears. In reality, I would have been thrilled to have a NV5600 trans. It is a great transmission.



My suggestion would be to keep your excellent performing 6 speed, and just fix your clutch master issue. Many of us run upgraded clutches – I have a South Bend with almost 40K miles on it. No issues with the clutch master or slave.



If your clutch has high enough pedal pressure to cause an issue, maybe you could try a slave cylinder with a slightly bigger bore? This could significantly reduce pressure at the clutch master, and pedal pressure.

I believe there is a 5 speed clutch slave cylinder that bolts up to the 6 speed transmission, that has a larger bore…?



Just an idea to consider. But then again, if you are like me and just like to tinker and try new things, more power to you.



Geoff

 

[oldbusguy]

mark look at a allision at545 that is what i am installing in my 250 it will bolt in with a little mod to the floor pan 35000 lb cap trans jack

 

[MChalkley]

JackL - I've seen the 545, but I have two concerns with it: First, it doesn't have a lockup torque converter, so you'd have to use an aftermarket one, along with a controller. (This probaby isn't too big a deal, since you'd probably want to do that anyway. ) Second, and a much bigger problem to me, is the fact that Allison only rates it for 445 ft/lbs of torque. I realize that Allison is very conservative in their ratings, but that's way too far outside my parameters for me to be comfortable trying it. I've already killed a Getrag (not too hard to do, of course), and seriously wounded a NV5600, so I'm not going to that much trouble and effort the third time around unless I'm pretty sure ahead of time that the transmission can take the punishment. I'd just give up and go to a dump truck or something first, but that's something I definitely don't want to do.



gbm - I agree that the NV5600 is a great transmission, but it's unfortunately not great enough for my purposes. I've already been told that rebuilding it would run at least $3k. Considering that I paid over $4k when I bought it, and it's only lasted 30k miles before starting to growl in 3rd and 5th gears, that doesn't work to being a very good investment. Maybe mine was a lemon - it certainly was a very early production model, so I could've just gotten a bad one. It's hard to say, and of course there's no warranty on anything when you play, so you have to be prepared to pay. So, for those reasons, I don't really want to upgrade the clutch and master/slave cylinders either.



So, all that having been said, another "progress" report: I've talked to a dozen or so different guys "in the business" so far. Most of them fall into the "we'll be happy to fix you up as long as you're happy to pay the price" camp. I don't mean that as a criticism - I like folks with that attitude, as long "the price" is reasonable for what's being done - a lot of money for a lot of work and parts, in this case. Minimum ticket just for the transmission work seems to be about $10k so far. Then add in the diff work, etc. , etc. , ad infinitum, ad nauseum.



Another option is to buy a 643/Gear Vendors overdrive from a TDR member who PM'ed me. He's got a very nice setup for a very reasonable price, but I'd have to use a divorced NP205, and the Gear Vendors unit would have to be mounted divorced, too, I think, and all that stuff mounted separatedly with connecting shafts sounds like trouble with a capital T, to me. Any thoughts? I'd really love to go that route, but...



However, one guy makes a very strong case for getting rid of my '93 (by parting it out, or selling it as a project truck, whatever), and buying a '97 or '98 Club or Quad 4x4, then starting over. His point is that by the time I've paid for the conversion, body work (did I mention that mine needs some body work and a paint job?), etc. I'll have more in it than if I bought a late model 2nd gen, beefed up the transmission (I could even do that after I destroyed it), and also have a stronger platform all around for the future. So, what do you guys think about that? I've spent 15 minutes looking at used truck prices, and I'm doubtful, at least about the money part. So, will the TDR "brain trust" weigh in on this one? (Maybe one of you has a truck you'd like to offer up for sacrifice? )

 

["Mad Max"]

Well, it's really going to get down to which body style you like best. Personally, I'm a true die-hard 1st gen fan - they seem to be so much simpler to tinker with and are I think a lot easier to see out of. That's why I like my 93 - last of the Power Wagons, but with the best of the Cummins, and has the adaptability for modern upgrades. When My rig is done it will be a brand new truck with the classic lines - there just aren't that many 1st gen Dodges out there, so I guess I like to have something a little on the unique side. Besides, even if I did get a 2nd or 3rd gen I'd still need to beef it all up, and I think the 2nd/3rd gens are just that much more expensive to upgrade based on newer body panels, parts, etc. When you're planning to u pgrade with major conversions I feel the 1st gens seem to be the least expensive of the gens.

Just my 4. 5 cents worth... but I also like to tinker and fabricate stuff... .

- S

 

[MChalkley]

Well, I do like the older body style best. And I have been a die-hard 1st gen fan, too, at least until I started researching this. Unfortunately, I have neither the time nor the equipment to do much fabrication and heavy-duty tinkering.



As for your comments on the '93 having the best of the Cummins and the adaptability for modern upgrades, what about those who say the new engines and pumps are much more "tweakable". You disagree? I'm listening, and would like to be talked into keeping what I've got, I think, but I don't want to be fooling with this project for the next 6 months, either. I need it to work with, not as a play project, and I can't afford to have two of them sitting around.



Thanks for your input,



Mark

 

[cerberusiam]

Mark, without mentioning names could you detail wht the $10k is going to get you for trans work? Pricing the pieces to do what I think you want gets me a little short of $6k plus the labor.



Like Sams says, if like the gen 1 body style and want to do it its money well spent but you gotta be happy with it and forget the economics.



From a purely economical view a newer heavier truck is the route you should go. You should be able to get a 97 3500 4x4 for around $15k. Obviously if you are going to work it you will also have to put $$ into it. The trans, auto or manual, will eventually need attention but the rest of the trucl should handle things nicely.



Once again its purely a personal choice as far as what you do. All of us that drive and like the first gens ask the same questions and do the same things. I fix the gen 1's and buy newer trucks depending on circumstances at the time and am always happy with my choice.



Good luck on whatever you do.

 

["Mad Max"]

actually Mark what I was meaning was I can have my 1st gen with a factory Cummins and still be able to modify it without having to change out wiring harnesses, K-frames, or other major frame modifications. I'm a VE pump fan, but yeah the newer ones are just as easy to bomb as the older ones. I like the VE because of its simplicity - much like a carburator, however I have never tinkered with a newer pump so I don't have anything to compare that to. I imagine if I had a 2nd gen and started tinkering and taking things apart and reassembling them I'd learn how to go about that just as I have with the 1st gens - I just like the older body style. :-laf

- S

 

[MChalkley]

Interesting, Sam. It's funny, because when I talk to the guys at these shops that do this stuff, I keep hearing muttered comments like "well, you can't be getting enough power out of the old engine to" etc. etc. The implication being, and some have actually said this, that you can't "hop up" the VE pump enough to get as much power out of it as you can the newer style pumps. I don't understand that, because mine puts as much fuel into the engine as it will burn, and it doesn't make much sense to put any more than that in. At that point, you have to start doing other things. Apparently, that's your feeling, as well.



cerberusiam - The $10k number is for flex plate, adapter plate, hopped-up transmission, torque converter, controller, plus _approximate_ numbers on driveline work, mount fabrication, and redoing the input shaft on the NP205, I think.



Thanks again guys. It helps to be able to kick this stuff around with other nuts.



Mark