NV4500 lube question

[ezcurra]

Hello,

My NV4500 has had water inside and although it turns and shifts very nicely, some surfaces in the gears have fairly thick rust. I've been removing as much as I could, and I plan on flushing the trans before I close it again. I won't be able to remove all rust from the wear surfaces and I was going to fill it up with cheap gear oil, run the trans for a few minutes, drain and fill with the proper $$ fluid. Will this ruin my synchros? I really want to flush it this way, but the NV4500 fluid is very expensive.

Thanks,

Mikel

 

[amsoilman]

Your truck transmission (NV-4500) uses a GL-5 rated 75W-90 gear lube, so any gear lube that meets this requirement will work just fine. I would change out the fluid, run it for a couple thousand miles, then change it out again, and again. I would not use solvents of any type to "flush" the trans, as these types of fluids can effect the syncro's.



Wayne

 

[ezcurra]

Thank you. I pulled the cover and after cleaning, I was going to flush the inside with brake cleaner. Will this hurt anything?

 

[Steve St.Laurent]

It's not GL-5, it should be GL-4 rated 75W90. Amsoil makes a lube specifically for the NV4500 that's far cheaper than the Castrol stuff - Amsoil Synthetic Transmission Transaxle GL4 Gear Lube .

 

[BJMarshall]

It's not GL-5, it should be GL-4 rated 75W90. Amsoil makes a lube specifically for the NV4500 that's far cheaper than the Castrol stuff - Amsoil Synthetic Transmission Transaxle GL4 Gear Lube .

I don't know, Steve. The website lists this stuff for $9. 90/quart. I pay less than that for the oil at my Chevy dealer.

One problem, besides the rust, you may have is the fiber clutch material on the synchronizers. If they get wet, the fiber can lose its adhesion to the metal part of the synchronizer. I would definitely consider tearing it down and replacing the synchronizers.