Engine/Transmission (1994 - 1998) Nv4500

[AWallace]

Whats the percentage of 5th gear failure with the upgraded shaft. I have got to pull my trans soon to check the pilot bearing. Truck has 115,000 and I am looking at when not if this thing fails. I pull between 9 and 10k and in 5th as long as I can keep my rpm's above 1600 have since new. I don't want to spend 2k + if it not going to fix it. Thats with shipping and new clutch parts.

 

[GAmes]

In my case the percentage was zero. My original 5th gear came off at 87k and I had an upgraded shaft and gear installed by Standard Trans. Shortly after that I started towing trailers commecially. I went through 8 or 9 NV4500s, all of them with upgraded shafts and gears. None of the 5th gears came off, but I found the NV4500 was never designed for commercial use. To lengthen the life of the trans, keep the boost below 20 and the rpms above 1800 while in 5th when towing.

 

[hsmith]

Gary, it is no fun below 20 psi boost. Just kidding. How's the engine oil consumption issue?

 

[GAmes]

Gary, it is no fun below 20 psi boost. Just kidding. How's the engine oil consumption issue?

20 psi in 5th, and only while towing:-laf Oil consumption got a lot worse on this trip. I have a new turbo on the way. I think I wore yours out.

 

[AWallace]

Thanks Gary for this info. Since I bought the truck in 95 I would say 95% of the 115000 miles has been towing a 5th wheel or hauling a truck camper. I am going to pull the trans in a couple of weeks the gears have become notchie 2 to 3 to 4th. I hope it is a clutch or pilot bearing issue and not the syncros. This problem started in Nov. but has not been driven much since. As long as I don't shift hard it is find just not smooth as it once was. I have checked slave cylinder and it is ok. There is no noise anywhere.











5

 

[NIsaacs]

In my case the percentage was zero. I went through 8 or 9 NV4500s,



Gary, do you remember what was failing? Thats crazy, I always figured the NV4500 was a pretty good transmission.



A friend of mine's son just lost his NV5600 in his truck (same as my '01) so he replaced it with an NV4500. He was told they were better. His truck just put down 460 HP at the dyno days yesterday so I think it will be short lived:-laf



Nick

 

[GAmes]

A couple of them failed with less than 10,000 miles because of (I believe) faulty rebuild. The others lasted 80k to 100k and were worn out. Towing heavy in 5th gear really hurts them. I also found that with the Amsoil substitute oil the trans didn't last as long as when using Syntorq. I don't think short blasts of power will be much of a problem, on the street a 2500 will more than likely break the tires loose before the trans will get damaged.

 

[AWallace]

Human error you don't know who to trust. I have rebuilt 3 and 4 speeds with no problem but this thing is a hold new ball game. I called standard and got a quote but maybe it will just be the pilot bearing. If it is and the shaft is bad from the bearing maybe I can just change it. But I will still have the 5th gear issue.