Engine/Transmission (1994 - 1998) Castrol Syntorque not cutting it in my NV4500

[Six_Man_Diesel]

I decided I would change the fluid in my transmission a while back, so I went and spent 60 bucks on a gallon of fluid at standard transmission. Now after running the truck for 15 minutes, the third gear syncronizer acts weak, grinds if you don't let the rpm's fall, doesn't act up till the truck has been ran for 15 minutes or so. I noticed the fluid that came out of the transmission was thicker than the syntorque, man that stuff is thinner than water I think. Has anyone had anything like this happen to them? I am thinking about switching to a tad bit thicker fluid myself. What are you guys POV on this??

 

[baby.driver]

After the dealer installed my NEW replacement 5sp I ran it for maybe 5000 miles before switching to Castrol Syntech GL5/MT1.

20,000 miles later and she's still working good.



Jay

 

[M Barnett]

Changed mine a couple months ago and stayed with the Syntorque and no problem. Is it a clear oil you have? Wonder if they sent the wrong stuff. Seems like it was thin.

Michael

 

[Six_Man_Diesel]

Barnett, it is a clear thin fluid, so I guess it is the right stuff, man that stuff is thin. I might drain it, and keep it and just try some other fluids, like the Gl5/Mt1. If no change after that, guess I'll be getting a new syncro for third gear, that will be fun to install LOL. Thanks for the reply guys, keep em coming.

 

[LarryB]

I had been running LE607 in my NV4500 for 10K miles. Just changed to Syntorq and temps dropped 20-30 degrees on last trip. Now it runs same temp as my Dana 70. I'm thinking of trying Syntorq in my USGear 2sp because that still runs too warm for my liking. Although it is running a bit cooler now that it's getting some miles on it. Yes Syntorq does seem very light but that's what almost everyone recommends.

 

[M Barnett]

Whatever you do, don't worry about how thin it is. One of my drivers has a Ford 460 with standard transmission and it uses auto transmission fluid! Some units require thin oil for proper circulation to all componments. The old school of thicker is better just doesn't apply any more. The trouble sounds like its the transmission and not the oil.

Michael

 

[patrobertson]

Maybe bad news

I just put a new sb clutch in my truck and went to put the transmission back in and I had a broken gear on the countershaft. Well with 180k I thought I would do the whole bench rebuild. Well ended up being cheaper to get a remaned unit. The old one was fine except the tooth and just plain wear. But the new unit runs cooler, and is quieter over all.



Shane



When we looked at the manual the transmission needed special tools to take it apart so we just went to a truck transmission place.

 

[Six_Man_Diesel]

I just purchased a gallon of Amsoil GL-4 MT 1 synthetic 80-90 lube for 26 bucks, does anyone else run this stuff?? I checked the owners manuel on my brothers 2002, it said use a 75w synthetic oil GL-4 and API approved, or similar. I think the type of oil one uses should depend on how they use thier truck, hotshot, or just haulin a$$ around. I drive about 170 miles a day, haulin nothing but myself. Also, on the climate where they live. If I lived in Alaska, I would want a thinner oil, since I live in good ole Texas, I like Thicker oil, since it is obviously a warmer climate here. I'm no Diesel Mechanic, will be in 2 years if everything goes as planned, but that is just my honest opinion, I am certainly not trying to start a war here, but I like opinions.



Willie

 

[David Oxland]

Anyone in Canada got a good source for Syntorque?