Engine/Transmission (1998.5 - 2002) NV4500 Death Rattle??

[GMincher]

I've searched the threads trying to find more info on this problem without much success. Let me pick your brains!

Truck is pushing hard on 150,000, transmission makes a chatter/rattle under heavy load at low rpm. Such as making a right turn that doesn't require 2nd gear but third puts rpm's below 1000. Once rpm's build noise fades away.

This noise isn't new but it used to only do it when towing, now it does it empty. The gear shift lever also seems to have quite a bit of vibration in 3rd, 4th and 5th. Also not new. There were no shavings or unusual colors when I changed the fluid.

While I'm typing I'd like to commend whoever it was I spoke to at Standard Transmission. Instead of trying to sell me a transmission he asked pertinent questions and recommended driving it til' there was an identifiable problem. I take this as the ultimate in honesty. Thanks for your thoughts, Greg

 

[Jed]

I had same symptoms, royal purple helped keep it quiet until I had it rebuild. By the way the rebuild kit for it is not very expensive.

 

[obert]

but third puts rpm's below 1000. Once rpm's build noise fades away.

Its called gear slap in some circles. Expect it. You havent noticed it before, but with the milage, maybe its just becoming audible. 900-1100RPM, or around that, will vibrate the "H" out of you clutch and tanny, and its bad for both. Also, the power might be there, but that low of rpm strongly dissagrees with the bottom end of the engine. Rod bearings take a huge beating from that.

Im not on a soapbox, but based on the problem description, I'd lay money there is nothing wrong with your transmission.....





on edit: think yours is bad?? listen to a FRD/Navistar444E(aka powerstroke for the ignorant) with that ZF transmission rolling through the bottom of the tach..... WOW!!

 

[RJPotts]

I agree with obert. RPM that low will cause some bad stuff and will definitely speed up the arrival of the symptoms you're describing.

Lugging it like that, especially with a load causes a lot of runout with the crank that will eventually eat up mains among other things. Like the block itself.

Keep them RPMs up, thats more fun anyways.

-R. J.

 

[GMincher]

Thanks guys, I guess I'm just soft hearted on machines and just tend not to keep things wound up enough! What's funny is that the transmission was Amsoiled and I went back to O. E. and it was much improved. Amsoil thinner possibly?

 

[skooterwerx]

my 03' was making the rattle and eventually started to do it at idle. Finally tore it apart and my buddy owns a trans shop said he has seen the problem in other nv4500s . Anyway fifth gear bearing wears the bearing and gear out he says its an oiling problem and after a new gear ,bearing kit , and everything else the parts were just 500 dollars. and no labor!!! NO MORE RATTLE!!