Engine/Transmission (1998.5 - 2002) 5spd transmission broken - what to do?

[JAlford]

This is my '99 3500. This transmission has been rebuilt at 95K (5th gear nut backed off) and 155K (leaking fluid into clutch due to metal destruction of bearings - from defective aftermarket rear case). This latest failure was at 177K, 12K on transmission after last full rebuild. The 5th gear self-destructed suddenly.

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Failure occurred at the end of a 3500 mile trip towing our camper. I am below the GCWR at 19600#s combined wt, only use lowest power setting on the SMARTY, turn the Edge Comp off, and stay at the speed limits. I do tow in 5th gear, but don't allow the RPM's to drop below 1700 without downshifting.



What have others done to keep their 5spd transmissions alive? I cannot justify spending $$$ on upgrading the transmission to a 6spd to tow 4 -5 times per year, on a truck this old.

Jeff

 

[jelag]

We had an 01 with the 5 speed, that we towed with all the time... we found that the OD wasn't designed to handle any amount of load... . if we rolled off the highway we'd down shift, if we'd start an incline we'd down shift... . we only used 5th when we were on the straight and level and we started to change the oil every 8-10 months...

That was the only way we got any life out of it... . we've also had the same issue with the 6th speed, pulling heavy loads... . trailers over 18K lbs... on this transmission we've learned to leave it in 5th... .

Hope this helps... .

 

[JAlford]

I have had several people recommend staying in 4th. Problem with that is highway speeds. This engine combination wont turn more than 2300 rpm without sending the EGT's above 1400deg with a load, so I am limited to no more than 53mph. My fuel mileage also drops to 7mpg when I have tried to do that.

It may be that this engine just doesn't turn the rpms, as the truck when brand new and stock ran 1450 deg EGT's when loaded if the rpms were up. I have always just kept the rpm down and everything works fine.

I also know the trucks that are hot-shot driven are not using 4th gear, they couldn't make the delivery times. But maybe they aren't using the 5spd trans either.

I know now that when Dodge list GCWR 20,000lbs, they mean only if you plan to rebuild the drivetrain every year. Unfortunately it is too late for us, as we have owned the truck for 11 yrs and really like it otherwise, so well that we purchased another one in 2006. But with the automatic transmission, and then discovered that the auto trans will overheat every time we tow.

So we are back to square one and searching for a solution we can afford.

Jeff

 

[champspa]

you need to get rid of half your tuners so you can go faster. I tow a goose with a 10k tractor on it, trailer at 6k and go up, down and all around Va. Nc. and Md. no problems it will go up and over the Blue-Ridge in Od at the speed limit with no problem .

 

[JAlford]

Champspa - Not discounting the fact that the engine performance components are likely involved with the engine not to be able to turn more rpms, but the truck couldn't pull this trailer when stock was why they are there. You have the old 12 valve reliable, and with an auto trans, so I am not suprised that you don't have problems. My first Dodge was a '89 automatic that we pulled backhoes on 14K trailers with, and it did a much better job than this truck did stock. It was long gone when we bought this one.



I have tried running without the SMARTY and Edge Comp, and the EGT's go to high if the rpm is up, which is why the problems with the transmission keep happening. I have always refused to let the EGT's go above 1250deg for any length of time, and the only way I have found to make that happen is to keep the rpms at below 2300. At 2000rpm, the truck runs really great, 1050deg EGT, 36psi boost, loads of power, and will get 12mpg towing. I just can't keep the transmission from exploding in 5th.



If anyone out there has ideas on how to put load on the 5th gear, please share. I have spent thousands on trying stuff to get it to do what Dodge's brochure said it would do stock, and I haven't been able to do it reliably yet.

Jeff

 

[champspa]

I would like that 12 mpg but 10 to 11 at 65 is about it, 1800 rpm is the best place for me . it will climb hills at that rpm that 200 rpm lower and it will fall down on the same hills. who can tell .

 

[Bill Stockard]

Why do you not tow with your '06? It has the ideal rear axle ratio for towing.



Bill

 

[NIsaacs]

He said his 06 auto overheats. The 99 is probably a dually also.



Nick

 

[SRath]

Get ahold of Quad 4x4. He has 'the ultimate fix' for NV4500's, as this thread, and many others I'll wager, mentions: https://www.turbodieselregister.com...-1998/222157-5th-gear-nut-quick-question.html

If he can't rebuild an NV4500 to handle your needs, I doubt if anyone can. Here is Quad 4x4 > Home

 

[JAlford]

Bill - Yes, the 06 has the perfect ratio, just has automatic transmission problems. I kept taking it back to the dealer when new until they told me not to bring it back, and Chrysler's customer service was worthless, finally told me that I was not driving the truck right and was overloading it, though I sent them pics of the weight tickets. I finally took it into a independant transmission shop when the warranty ran out and they replaced several electronic components and put a double deep mag-hytech pan on it, and it helped tremendously, but still didn't fix it for towing. The trans temp light will come on if you are doing any in-town or slow driving while towing, I have a temp gauge and have seen close to 300deg. It has a serious shift problem that even the trans shop cant fix. With the trailer, at slow speeds, it shifts in and out of 1-2-3 almost to the point of making you seasick. That also kills my fuel mileage, as we average 7mpg on trips towing. For what we use the truck for 95% of the time, just putting it in tow/haul mode corrects most of the shift issues, but only if unloaded.



The 99 is a dually, and I could increase rear axle ratios if that would solve the problem, but since the problem is 5th gear and rpms, it would slow me down further in 4th than I am even now. So I don't think that is a solution.



SRath - I know that Quad 4x4 does good work, and I have talked with him. He said that he could not build the 5spd transmission to handle that loading in 5th gear, and he cannot get parts for the transmissions any more, so is not rebuilding them. He suggested going to the NV5600, but warned the cost for rebuilding is 4x the NV4500 if you can get any parts.



Right now we are just trying to make ends meet, so replacing the truck is not an option, and we owe more on the trailer than we can sell it for, so the trailer sits in the yard, and the truck is in the garage up on stands with the transmission in the floor. I guess we are hoping for a small miracle... .

Jeff

 

[hsmith]

My 4500 has held up pretty well considering I tow a larger and heavier fiver than you do. Lost fifth gear and had it rebuilt locally with the upgraded mainshaft, etc. I have the GV and never tow in fifth, just 4th over. Just lucky I guess. I tow a 37 Alfa Gold at 14k empty.