Do you guys just put regular tranny oil in your getrags or are you using synthetic oil in those? My mechanic tells me that everyone is going to synthetic. Whadda ya think? Thanx

 

most guys run synthetic, i dont, i run 80/90 gear oil in both trucks

 

5w30 synthetic motor oil is what I run in mine. Over fill it by one quarts when you do change it.

 

Doesn't it shift a little hard with 80-90? I've always heard that 80-90 is too thick to lubricate the bearings in these things. I run 5-30 syncromesh amsoil in mine.

 

shifts fine

 

Synthetic 5W-30 engine oil or a manual trans oil like Redline MTL, Royal Purple Synchromax, or GM Synchromesh for better shifting.

 

I run 80-90w in mine now for years, also run a quart of lucas gear additive. No noise, vibiration and it does shift just fine

 

I sometimes suspect that the bad things that have happened to some of the Getrags could very well be due to our belief that we are doing it a favor by using light synthetic oils, when all of those that "don't know any better" have only ever used 90-wt and have no issues at all, and have no idea that they should "overfill".

99% of older vehicle owners will put 90-wt in ALL gear-boxes with no thought about it; if it's a gear-box, then 90-wt is what it needs.


I still use five quarts of 5W-30 full synthetic in all of mine.

 

I put 5 qts of Royal Purple 75/90 gear oil in mine before I knew better. Thats what the guy at the auto parts told me it used, I guess he was looking at the NV4500. Still, it shifts a little slower in the cold when you first start it up and drive but after the first couple miles it warms up and shifts like a dream. Runs much smoother and quieter with the RP geal oil in it though. I'm just leaving it in there.

 

Yeah, everyone is going Synthetic because oil change places are all pushing it and trying to sell more expensive oil. I don't buy the synthetic song and dance. Do what feels best, you'll never find agreement on this issue. People who think synthetic is a good thing will not be talked out of it or convinced otherwise. Just the way it is.

 

I don't know what "regular tranny oil" is.