Engine/Transmission (1998.5 - 2002) nv4500 transmission

[SAndreasen]

Would like to know everybodys nv4500 transmission experience ? How many miles and type of use and horsepower your putting through it

 

[MMeier]

Well, lets see now... my old 97 that I'm trying to get back has about 180k or so miles towing heavy most of the time on it, shifter is getting kinda sloppy but still works ok, has the upgraded splined main shaft in it iirc. Truck should be around 500 HP or so. The 4500 I put in the 93 has about 40k on it now and shifts smooth as butter and very precise, occasionally tows a single enclosed trailer and runs very cool also. Should be around 285 hp . First CTD, a 94 4wd had a stock 4500 in it was fine also for the short time I had it. Overall, I'm very pleased with the 4500 !

 

[SAndreasen]

Thanks for the reply

 

[gtwitch]

I had some posts over the last 6 or so months about my NV4500. I have 210k on my 99CTD 2500 and at 207k last spring coming home from a 200+ mile snowmobile trip towing my 33 ft enclosed trailer with 5 machines in it, I lost the NV4500 about half way home on a 30* evening after pulling some low to moderate hills.. Trans was hot and smelled of 90 wt lubricant, not low on lube oil, and wouldn't go into any gear at a crossroads, just like the stick would not select and move the shifting forks, managed to get it into gear by forcing it with the engine stopped and got across the road to a wide spot in the side road and called for my daughter in law to get in the 8.1 Chevy with the Allison to come get us and by the time that she came the 45 miles to get us, the NV4500 had cooled off and would go into any gear and I was able to get it home without the trailer that she pulled home. I drained the oil thru a paint filter and found what i expected,,, metal of both colors and some magnetics in the filter as well as on both magnets in the transmission (has FAST cooler). I had AMSOIL Sevear Gear 75-90 in it and after calling AMSOIL tech, they told me that I had put the wrong oil API GL5 and should have use the direct replacement API GL4 for the SYNTORQ recommended by Dodge and Chevy for the NV4500. This oil had over 100k on it and I do think this caused the failure and was my fault along with the fact that I had not changed it for 100+k miles. As one to the folks on TDR said, "These newer transmissions 5 or 6 speed are not "Lube for Life"" and should be changed at the intervals recommended in the owners manual. Expensive lesson but I did not get new truck fever and repaired it with a "new" NV4500 in the MOPAR box that I found, for not new price and is now running and I overhaul the 241DHD transfer case while I had it out and all is happy now with Amsoil API GL4 direct replacement oil for the Castrol Syntorq. Now if I just had both front replacement fenders to replace the rust that I can see thru I will be happy for the life on the 5.9 Cummins.. We can all learn from my mistakes and I have many in my life and my 72nd birthday was last week. Sorry fore the long diatribe!

gtwitch in wyoming

 

[SAndreasen]

The sad thing is even in schedule b there is no interval for servicing the trany at least in either of my 98 books . I do em once a year or about every 30,000 miles a filter really helps keep that oil clean as well.

 

[surfbeetle]

225,000 miles on mine. We pull a 11k pound fifth wheel. My trans is the original 19 year old unopened trans and has only been out at 180,000 to replace the failed pressure plate on the clutch. I run Royal Purple in it and have done so for at least a decade, before that I used Valvoline. The only time the syntorq was in it was from the factory. The truck has a TST #5 fuel plate and estimated 600 ft pound of torque.

 

[HHhuntitall]

189K is the max I've ever gotten out of one. But I can't leave an engine alone, after 36k it went to a mild tune of around 35psi boost until about 80-90k.... then it was doing 45-48psi boost for almost 100k, before the countershaft bearings checked out. I had a cooler on one side, and an Eaton filter kit on the other. And don't ask me the unloaded mileage, as the truck weighs 12k lbs empty, and almost never runs a full tank without a trailer.

I had another that I sheared the input shaft off at 65k, replaced it with a 1 3/8" shaft, and it's still running at 290k. That engine makes around 40psi boost, and tows pretty regular, probably 60-70%, and only 50% of that is very heavy.

The one I fairly recently installed in my '93 is functioning perfectly, with the Ol' Gray Goat making 38psi on cold mornings. I've never dyno'd it, but it runs very well, shifts fairly stiff still, and has around 25k on it. I like it a lot, and it's a very muchly needed upgrade to the G360.

The biggest complaint I hear about the 4500 is the big jump from 3rd to 4th. I don't really see it on the highway with the tuned trucks I've got, but off road it can be a problem. And in a stock tuned truck, it can also be a problem. And if you like to hot-rod your truck, that spread out pattern is much better than a 6 spd, IMO.

 

[KATOOM]

They're a mechanical device which means they're not impervious to failure for many reasons. But that said I think the best ways to help reliability are by using the proper lube, clean lube, and cool lube. I tow a 14k 5th wheel and to assure the most reliability I could from my 4500 transmission, I installed Fast coolers which not only dissipate heat but also added 2 more quarts. I also installed a exhaust heat "blanket" (not wrap) over the entire length of the exhaust pipe running past the transmission and transfer case. Then I installed a temp gauge to monitor the running temps at all times. So with almost 7 quarts in there, the coolers, and the blanket, I can tow a large house behind me doing 60 mph in 4th (1:1 direct) gear and the transmission temps will maintain around 150*-160*. The temps only start to climb when I'm pulling long grades and need to downshift. At that, the hottest I've ever seen the fluid get was around 210*-215*, and that was at the top of a long climb in the 100* summer weather. Not all oil brand and type is the same but generally once the temps get over 240*-250* oxidation sets in and lubrication reduces.

 

[RikDavis]

500K on mine in 99 stock truck. No problems of any kind. Several 100K towing assorted trailers to dealers. No unusual maintenance schedule but I am a fairly conservative driver