best transmission fluid

[LuckyWinner]

What is the best transmission fluid to use in my TKO600?

[FritoBandito]

Stick with the recommendation. Tremec recommends GM Synchromesh part #12345349 which has been replaced with AC Delco part number #88900333. Pennzoil Synchromesh is pretty much the same thing but easier to find. Bobistheoilguy.com has a number of discussions on flakey Royal Purple Synchromax shear strength so I'd avoid that. Some folks swear by Amsoil Synchromesh but I haven't seen a lot of info to back that up so I'm playing it safe.

Mario

[edwardb]

The place I bought my TKO600 is a Tremec elite distributor. They strongly suggesting using nothing but GM Syncromesh in it. They also were pretty strong about not the "equivalent" brands (like Pennzoil) but the actual branded stuff. As Mario already said, the GM part has been replaced by AC Delco 88900333. It's available in some retail stores and at GM dealers, but pretty pricey since you need most of three quarts. I found the best price at Summit and had it at my door in two days.

[Bob Cowan]

I have used both GM synchromesh, and Royal Purple. They feel about the same, and cost about the same. I tried Penzoil, and it definatly degraded shift feel - especially at high rpm's. I currently use the GM stuff.

[CraigS]

I am using the GM in my TKO500. Yep, is a little expensive but nearly every Chevy dealer has it so why not. I don't like changing trans oil enough to feel like experimenting.

[Avalanche325]

I did some reading on this recently. Pennzoil is not the same, even though they claim it is compatible. I haven't read about failures, just degraded shifting.

You can easily order Synchromesh from Summit if you can't find it locally. ($8.97 / qt) It is now labled AC Delco.

I figured for the cost of the TKO, I'll follow the recommendation. Of course, you would figure that for the cost of a TKO, Tremec would update the part number.