Oldssupreme

Hi everyone. Just wondering what type of trans fluid to use in my 72 TH350? And how many quarts should it take if it was drained? Also how about brake fluid type (I have an aftermarket disc/drum setup inline tube) and amount and power steering fluid and amount? I know engine oil should have the zinc additive. Any particular brand you recommend? Any other fluid advice? Thanks so much!
Chris

joe_padavano

Dextron for the trans. DOT 3 or (preferably) DOT4 for the brake fluid. Fill the PS reservoir to the line on the dipstick.

Oldssupreme

Thanks Joe. What type of power steering fluid do I want?
Chris

Oldssupreme

Regarding the trans fluid, do I want Dex-4 or Dex-Merc or are they interchangeable? It's a stock th350 from 1972.
Thanks!
chris

Oldssupreme

In addition to my trans fluid question above, I was told by someone NOT to use synthetic motor oil or trans fluid in my stock original engine and trans. Thoughts?
thanks
​​​​​​​chris

Fun71

I use whatever the local parts store has with Dexron on the label. Just not the synthetic stuff - it's too pricey for me.

Fun71

Synthetic works fine but may leak past the old seals and gaskets.

Oldssupreme

Fun71 so you buy tr dexron not the Dex-Merc?

Oldssupreme

Thanks for the info on the synthetic leaking. I didn't know that.

Fun71

Whatever the store has with Dexron on it. The last time I bought some it was the Dex-Merc stuff. It's all backwards compatible.

BangScreech4-4-2

When I re-did my brakes, I used silicone fluid. It's been in there for ten years (but admittedly not that many miles) with no problems.

Fun71

That would be silicone fluid. Silicon is a hard, brittle, crystalline solid element similar to glass.

BangScreech4-4-2

Uh-oh. I think I may have made a big mistake ...

Fun71

That's the same thing the blonde who got silicon breast implants said.

oldcutlass

But they were firm...

jaunty75

Dex-IV is not interchangeable with Dex-Merc, at least according to the label below. You want Dex-III for your car, and Dex-Merc will work.

To be more specific, Dex-Merc is fine for any pre-2006 GM car and pre-2007 Ford vehicle.

This is what I just put into the transmission on my '78 Toronado. Note what it says on the back label regarding compatibility.

This will work fine in a '72 GM car.

jaunty75

I just put in whatever 10W30 or 10W40 is on sale and then add a container of STP Oil Treatment, which has the needed ZDDP.

Oldssupreme

Jaunty, thank you so much!