It's almost time for a trans fluid change again, turbo 400 with shift kit. What are most of you using ?

No problems works great, 5,000 since last change.
Nothing over the top, non synthetic.

Think i have some quaker state dex III left.

 

Just a decent brand of Dexron ATF. Until someone comes up with some real data that synthetic will allow the older trannies to work as intended (frictional differences when the clutches apply??), I'm staying with the standard stuff. My THM-400 has 202,000 miles and counting and it has never been out of the car. I guess regular Dexron works OK.

I really would be interested in using synthetic lube in the tranny...I know that it is so much better with regard to wear resistance, heat tolerance, etc. etc. But, I don't want the shifts to be slower to apply due to increased lubricity. So I'm stickin' with the "old stuff".

 

I'm using the TCI transmission fluid on my '78 Camaro with a TH350. It too is due for a fluid change and I'm planning on going with the TCI fluid again. I have a manual/automatic valve body on it and a slightly higher stall converter and the tranny is holding pretty well.

 

Is the Dextron III recommended for the TH350?

 

For a synthetic, I'd look at Allison transmission's "Trans-Syd". Only problem is it was $38/gallon.

Plain old Dexron series fluid works very well. And for a long time.

 

My 78 is a 4 speed but I have been using Mobil 1 ATF full synthetic in my 1994 Ford Mustang GT convertible with the AODE automatic since 1998 which is basically a lousy transmission with no issues so far. I changed the original transmission fluid (Mercon) in 1998 at 20,000 miles when the transmission was shuttering between shifts which it has never done since the switch to Mobil 1. I used the same Mobil 1 ATF fluid until 2008 (10 years and about 10,000 miles) and changed it again then with Mobil 1 ATF at that time. I also completely removed the tranny lines from the radiator in 1998 when I switched to Mobil 1 and cooled the fluid with 1 28,000 GVW Long Double Stack cooler which is still used today. The AODE uses 12 quarts of fluid for a complete change including draining the torque converter and both times I bought the Mobil 1 ATF fluid at Walmart for about $6 per quart although my local Walmarts no longer carrying Mobil 1 ATF. I have a Transgo shift kit that I am about to install in the AODE since these transmissions are notorious for very lazy shifts and since the tranny fluid has only about 1,000 miles on it, I am considering saving the fluid when I do the shift kit, filtering it and reusing it when I put the pan on with a new filter.

I believe that Dexron VI, the newest GM fluid, is backwards compatible with all Dexron required transmissions and I use Dexron VI in my 2001 Pontiac Grand Prix transmission that originally required Dexron III. Supertech Dexron VI can be purchased at Walmart for about $3 per quart which is what I use in the GP, 102,000 miles on the 4T65E crap FWD transmission. Hope that helps!

 

I used Mobil 1 Full Synthetic ATF in my aunts '91 Firebird 5.0 with the 700R4. I changed the filter and drained the fluid and put in the new stuff. It shifts so smoothly and was a great investment into the health and life of the trans. Its still running great after about 1000 miles on the new ATF and Mobil 1 Synthetic 5W-30!

Will