Would yall recommend synthetic in the rear end? Ive heard some do some dont but figured Id get a new fresh opinion. Also would I still need the GM additive if I go synthetic? and should I run 75-90 or 80-90?

Pretty much the same question on the tranny. Should I use synthetic in the tranny? I looked for a filter kit at the store today but they said one was deep pan and one was shallow. How would I tell which one I have?

 

I run Amsoil Severe Gear 75-90 + Amsoil Gear Additive for Gear Oil.

I know my rear had a whine on decel that I could hear over the radio, and the Amsoil Severe Gear cleared it up completely!

Here's a study done a few of the most popular Lubes: Gear Lube Comparison

I would also think one of the Amsoil Transmission Fluids would be a good choice.

I run the Amsoil Manual Transmission Fluid in my car and it also cleared up notchy/sticky shifting... So I can only imagine that the Auto Fluid is up to snuff.

PS - You can probably also guess I run Amsoil Oil as well: Signature Series

 

So I should run 75-90 instead of 80-90?

And I wasnt sure if I should put synthetic in either seems like some say it causes issues?

 

I'm not sure why folks hate synthetic so much.... Other than price it's always treated me well... And yes 75/90....

 

thanks for the advice. i guess ill go with synthetic all around and see what happens. i dont suppose it cant hurt the tranny nor rear end switching.

 

I recently swapped out my fluids with lucas products. The rear diff fluid and their ATF additive. Both fluids did make a difference. Especially the trans additive. It cleared up that annoying bearing whine and the chattering gears when the tranny gets hot. Im definately sold on the use of synthetics.

Brian

 

Sorry to bring up an old thread, but i am getting close to changing the rear seal in my rear end and flushing the old fluid out, and this makes Royal Purple look really bad. Granted, i've only used their ATF fluid and it seemed to make a nice difference (at least to my butt meter), but has anyone else used there products for the 10 bolt? Also, anyone used their fluid in the T56? Just thought i would see what everyone is a fan of.

Sorry to hi-jack the thread