trans fluid

**Siciliano15** · 11-13-2008, 06:24 AM

just wondering if using synthetic trans fluid like amsoil or something would be better? i just got my trans am recently its a 98 with 50k on the clock. Id like to flush the old stuff out and put a quality synthetic in there for better protection and mileage. Only way to do this would be to have a shop to the flush right? i know dropping the pan only replaces 3 or 4 quarts.

**CompSyn** · 11-14-2008, 04:21 PM

Siciliano15,

Below is Technical Service Bulletin pdf from Amsoil on automatic transmissions.

Automatic Transmission Fluid and Filter Change Procedures pdf.

Don’t forget that Competition Synthetics is offering a 10% discount to LS1.com members for the month of November on Amsoil products.

Amsoil Synthetic ATF link

1998 PONTIAC FIREBIRD 5.7L 8-cyl Engine Code [G]

Automatic Transmission, Total Fill
4 speed 4L60-E..........11.0 quarts

CompSyn

**1TA LS1** · 11-14-2008, 11:24 PM

Fully synthetic trans fluid is much better than the regular stuff. And our cars deserve the best. But since you have a stock tranny (I assume), you really don't need fully synthetic. For now, drain it yourself and replace your filter and fill it up with 3 - 4 quarts of clean regular fluid. Plus, when want to change to completely synthetic trans fluid, you're going to need around 9 quarts. I would wait until you get a torque converter/stall to change to synthetic trans fluid, that's when you're going to need it. - I recommend Amsoil. Go with the 2.5 gallon, cheaper than buying the quarts.

**SteveC** · 11-16-2008, 03:33 AM

I would not run any type of synthetic fluid in the transmission, just use the Dextron III, and change the fluid and filter every 40K, and you will be o.k.

SteveC

**Firebirdjones** · 11-16-2008, 07:58 AM

I agree with Steve, I don't care for synthetic fluid in any automatic transmission. I was rebuilding them for a living and just don't like what I have seen. Good old Dexron III does just fine, even in extreme usage from my experiences. My only difference from Steve's recomendation would be to change it a little more often. Since as you mentioned dropping the pan doesn't get much more than 4-5 quarts out of it.
I like to change mine every 10-15,000 miles. As long as I keep up that type of service I have found no need to go with a full transmission flush. I've torn them down after 100,000 miles with 10-15,000 mile service intervals and they look beautiful inside.

**Siciliano15** · 11-16-2008, 06:18 PM

ok cool thanks guys. ill just drop the pan and change it out with the dexron 3. is the gasket re-usable or should i get a new one?

**Firebirdjones** · 11-16-2008, 06:43 PM

You'll get a new one that comes in the filter kit.

**CompSyn** · 11-16-2008, 07:58 PM

Originally Posted by Firebirdjones

I agree with Steve, I don't care for synthetic fluid in any automatic transmission. I was rebuilding them for a living and just don't like what I have seen. Good old Dexron III does just fine, even in extreme usage from my experiences. My only difference from Steve's recomendation would be to change it a little more often. Since as you mentioned dropping the pan doesn't get much more than 4-5 quarts out of it.
I like to change mine every 10-15,000 miles. As long as I keep up that type of service I have found no need to go with a full transmission flush. I've torn them down after 100,000 miles with 10-15,000 mile service intervals and they look beautiful inside.

I’m curious. What synthetic automatic transmission fluid do you not care for more specifically? Also, what issues did you see from using the synthetic ATF that you didn't like?