i was reading my Amsoil catalog today and read about this guy who has an 87 VW passat with 287K on it. I found this interesting when one sentence said "I use Amsoil 75W90 in my tranny" My question is this ok to do?????????? I guess it works for him but is this ok to do. Will it make the tranny last longer????? main question is it ok to put gear lube in your transmission?????

 

If it's a manual transmission it is. Manuals use gear oil. I have read recomendations suggesting a quart of 80 W90 gear oil mixed with ATF can be beneficial, but I'm not so sure about that.

 

Most modern manual transmissions use ATF, not gear oil.

Will gear oil harm the transmission? Maybe, maybe not. I wouldn't use my expensive transmission to test if it works or not.

Mark

 

Thanks, Mark.

My experiences with manual tranmissions have been that they require gear oil. Not always the case anymore but I'm pretty sure the VW referenced called for it.

The owners manual is usually a good indicator of what fluids to use.

 

I wouldn't use gear oil in any automatic. I use Mercon V in all my 4R70W's and I use Mercon V as my p/s fluid in all my cars.

Seabass

 

I once replaced the ATF in the Borg Warner T10 in my Mustang with 80W90 gear oil and it wouldn't shift well at all when cold. The oil is so thick that the synchros cannot perform their job of accelerating/deccelerating the gears before they mesh. It definitely wasn't doing the gears any favors but it probably eliminated any synchro wear. GlennMc.

 

You may be surprised but I have a 90 Honda which uses engine oil 5W30 for the manual transmission fluid. I checked the auto parts store computer, my owners manual and the Haynes repair manual. Couldn't believe it myself, but that is what it calls for.

They must have done something right. In 12 years the car has been in for one water pump. That was the only unscheduled maintenance ever.

Hunt4Fun