Which fluid for TKO?

[DarkoNova]

I bought a TKO 600 kit from classic Chevy 5 speeds a long time ago, and I vaguely remember putting synchromesh in. I've got roughly 20,000 miles on it and just got my car back from the body shop. They said that the tranny makes a lot of noise and asked what fluid I had in it. I told them synchromesh and they were shocked and said I needed to use ATF.

So what's the recommended fluid for these things?

[nokones]

GM Synchromesh Tranny Fluid. If you go to the Tremec website and look up the recommended oil for the TKO it will say the GM fluid and give the actual GM part number. As for using an ATF, they do specify a specific ATF.

Here is their (Tremec) recommendation on what fluid to use: A: For all TKO 5-speed models, TREMEC recommends GM Synchromesh™ (GM Part # 88861800) – or equivalent, or Mobil 1 Synthetic ATF. For all other aftermarket models we recommend Dexron III ATF

And their reason why: A: Some TREMEC transmissions are designed specifically to use automatic transmission fluids (ATF) for good shift quality in cold conditions, compatibility with synchronizer friction materials, and minimized parasitic drag to maximize power to the wheels.

And why they recommend "not" to use a hypoid gear oil: A: Hypoid gear oils are designed to withstand sliding actions at the meshing interface of bevel gears. Some hypoid oils contain extreme pressure additives that are corrosive to certain non-ferrous metals that are used in transmission parts like bushings and synchronizer rings. Also, the friction coefficient of some hypoid gear oils may be incompatible and can cause poor shifting. Both of these conditions can result in premature or excessive wear and failure.

I do love my TKO 600. I have the Sidewinder II Shifter and have never have missed a shift.

[Craig@Bowler]

You can also use Royal Purple Synchromax, or the Driven Brand Synchromesh fluids. Any of them will work well, but if you've got an issue going on in the transmission that's causing it to "make a lot of noise", new fluid will not fix it.

[DarkoNova]

Thanks guys. It's been a while since I've seen or driven the car, it's been at the body shop for about a year and a half. But I do vaguely remember it just having a rattling sound. I also remember that being a pretty common complaint.

It's definitely time to change the oil after sitting for so long, so I guess I'll just try putting in the proper ATF just to see if that helps at all.

[nokones]

I think the rattling sound may be the throwout bearing and yes, that is common. Only real race cars have a rattling sound at idle.

[badazz81z28]

You can also use Royal Purple Synchromax, or the Driven Brand Synchromesh fluids. Any of them will work well, but if you've got an issue going on in the transmission that's causing it to "make a lot of noise", new fluid will not fix it.

Agree, GM branded synchromesh is totally overpriced. There are definitely better fluids like RP. The GM stuff is simply penzoil

[DT69Cam]

My TKO from SilverSport Transmissions came with Penzoil Synchromesh.

[rich_fbodySS]

Mine came with the GM Syncromesh Oil....I've also used the Redline MTL, but it seems happier with the GM Synchromesh.



-Rich