JasonAndrew

Hello friends. I purchased a 2005 Z51 Silver with 13K miles. I am going to change the rear diff. oil with the Dexron LS gear oil 75W90 (From what I read on here) and have a question on the 6 speed: the owners manual specs DEXRON III ATF "approved for the H". Any recommendations? I don't see the GM specific oil on Summit's website, what would you recommend?

Regards,

EVRose

With only 13K miles I would leave them both alone, but that's just me.

Rick@RKT Performance

GM part # 88862624 for differentials and 88861800 for manual transmissions.

schizcat

A few on here have also gone with Redline.

CMY SIX

BG products "syncro-shift II" you won't believe how quiet the car can get!

Fly N Low

I have the same car and recently changed trans oil to Redline D4 Dexron. It lists the Tremec T56 trans right on the back label of the bottle. So it is what Redline recommends for that trans. After changing the fluid I noticed that the trans shifts much smother not as notchy especially going into 2nd. They make 2 different Dexron fluids the D4 is for the Tremec T56.