93 cummins gvw 40,000

[cumminswillie]

I have a friend that pull a 40 gooseneck with his 93 d350 4x2 auto. He is looking for more power and wants me to start doing mods. my fear is that with such high gvw that no matter what i do the egts will be high and the auto trans will not hold up. Any suggestions on what mods I can safely do

 

[seemore]

The first mod should be sell the truck and buy a SEMI, or please have him post his itinerary so us normal people can stay far, far away from his route!#@$%!

 

[Tippin Spotted Cow]

People do pull that kind of weight with pickups once in a while... . maybe not quite 40k, but people use 'em for well beyond what they're rated for. Power is not the only thing that needs upgrading though. Our motor, stock, can pull that weight, and more... as shown by some commercial applications of the motor. But now you're talking heavier duty gears, transmission, driveshaft... etc. And that's just to keep from blowing things in your drivetrain up. If you want it to be safe, then you better be talking bigger brakes, heavier duty suspension, heavier duty steering setup, heavier rated tire/wheel combo, etc... .



This, I'm sure, is a point of debate. Most people will say you absolutely cannot upgrade a truck to tow more than what it is rated for. I tend to disagree, but I use that statement loosely. The weight rating comes from thousands of hours of lab controlled tests to measure not only the strength of each individual component, but the assembly as a whole. The motor is only one component of that whole assembly. When you start towing more than it's rated for, you will find the short comings very quickly. I absolutely gaurentee that this guy's transmission is toast if you do basically anything to the motor and then he hooks up that trailer. Once the transmission is built to the hills, he'll start eatting u-joints, slip joints, driveshafts, differentials, axel shafts... . Next he'll be on to suspension and frame weak links, steering issues, braking problems... With plenty of money, time, research, and access to state of the art shops that specialize in every aspect of the vehicle, he could build that truck to safely tow the weight (and with that I invite the bombarding of naysayers, I'm sure), but by the time he's over and done with it you'll note a few things:



A)He'll basically have a truck that only resembles his truck in appearance and no other way



B)He could have bought multiple heavier duty trucks for the money he spent



C)It's still not LEGALLY rated for what he's gonna be towing, and that you'll never change



D)The process will start all over again when he realizes he wants to be able to tow 50k once he's conquered 40k





For the cool factor of a first gen towing an earth mover, I guess he can build up his truck. But if he's just looking for some way to tow his trailer around... there are alternatives.

 

[MEby]

The first mod should be sell the truck and buy a SEMI, or please have him post his itinerary so us normal people can stay far, far away from his route!#@$%!

Not to start a food fight here but, running 40,000 gvw is not the end of the world. I have run 35,000 to 40,000 lb several times SAFELY over long distances (several hundred miles). It all depends on the condition of the truck, what type of trailer he has and at least in part, depends on how often he does this and for how long. The one we used to have had electric/hydraulic brakes. The big trailer stopped faster at the above gvw than several of our smaller trailers that were under their weight ratings (I know because I tested it)


Now, to the original poster.

The first order of business would be to install a full set of gauges. Boost, pyro, trans and rear diff. temp. gauges would be a good place to start.

Second, a new tq. converter and a trans refresh might help a lot too.

Third, how much power does he want? The sky is the limit. After gauges, I would start turning up the pump and then maybe add a water/meth system to help combat egt's. After that, maybe injectors and a turbo. Of course, pulling heavy like that is going to wear out parts a lot faster than normal; adding power is going make them wear out even faster.

 

[RSchwarzli]

This, I'm sure, is a point of debate. Most people will say you absolutely cannot upgrade a truck to tow more than what it is rated for.



A)He'll basically have a truck that only resembles his truck in appearance and no other way



B)He could have bought multiple heavier duty trucks for the money he spent



C)It's still not LEGALLY rated for what he's gonna be towing, and that you'll never change



D)The process will start all over again when he realizes he wants to be able to tow 50k once he's conquered 40k



.

Hmmm, and what you have is a picture of my Crew Cab Buildup! :-laf



Yes it can be done. Point B then becomes very true!

 

[RedRamAndy]

Ok, here's my meatball in the food fight: The way I have approached every mod/buildup project I have done is from the ground up. I start with good tires, move to the best biggest brakes and then on to stiff, well-tuned suspension. Lastly I go for the eng/trans. Power is dangerous if you can't steer or stop it in a panic situation. As I'm sitting here typing this, I really can't get myself comfortable with 40k GVW. Sheesh... I talked to mysteryman and he told me what they (the engineers) went through to get this truck together. There's not much room for much cost-effective improvement in this design. Just my opinion with a strong agreement to Mr Cow's viewpoint.

 

[cumminswillie]

blown trans

he made it 200 miles on his maiden voyage and blew the torque converter out of the truck. what a mess

 

[RSchwarzli]

Were any mods done to it in the end, or was it all stock and his first time at 40K lbs?

 

[cerberusiam]

he made it 200 miles on his maiden voyage and blew the torque converter out of the truck. what a mess

That will be his problem for ever, can't hold the trans at that weight for very long.



Start with about $5k for a built 48RE and a controller for it, upgrade injectors and rebuild pump, add a new turbo, gauges, fuel system and that will get the power and thru the trans.



Swap the rear for a late model D80 and make sure you get the big u-joints in it.



Depending on how much he is going to run it at those weights, every year or so it will entail dropping the transmission and replacing hard parts in the OD. The OD will NOT handle those weights on a consistent basis, parts are just too small.



Even an NV5600 needs help to live towing that heavy.



It can be done but it is a pile of $$ up front plus ongoing maintenance.

 

[Tippin Spotted Cow]

I revise my answer, his first mod should have been a removeable transmission tunnel cover. That way when his transmission is glowing red and blows up from high horsepower and heavy trailers, he can at least pop off that tunnel cover and grill some steaks on that smoking transmission while he waits for the tow to show up.



These older automatics WILL NOT take that much weight with any bit of horsepower upgrades... . I just recently killed #3 in my truck in 3 years. When I go down a list of parts you "might" break, its probably a good idea to pay attention cuz odds are that's my list of parts I already have broken. How does the saying go? "I've been where you're going. "

 

[Cumminsduallyguy04]

wow alot of very unhelpful responses. I reccomend going to a medium duty rear axle assembly. My F650 can come in two configurations air or hydraulic brakes. find the hydraulic brake variety for ease of install. lower gears in the rear axle take the strain and load off of everything before the reduction ie:less load on engine makes it feel like it has more power, trans has less load torque converter and will build less heat, u'joints have less load etc. The f650 brakes are big and the axle rating can handle higher tongue weight (30% of trailer weight... you said total GCVW 40k is heavy trailer). source a heavier duty leaf spring suspension for the rear too at least. I would be sure to find a trailer with at least 3 axles. the more brakes you add the better and possibly source a pacbrake. but since transmission is broke and out i would reccomend billet flexplate and converter also add a 2nd transmission cooler. if you plan to spend alot of time in stop and go traffic or slow climbs up grades i reccomend a fan cooled transmission cooler. but now look at price of all this. was it worth it?

 

[WyattEarp]

and when seeing the thread title i thought surely not LOL, pulling i wouldn't worry to much getting stopped would be a whole new ball of wax WoW!!! and i agree i hope his trip is short, just my opinion but the risk outweighs the means when you seen what can happen from an overloaded hauler.