using ATF in 944 trans with factory LSD

[roadsportusa]

I have a 1983 944 with factory LSD in manual trans.
Question:
Should I use auto trans fluid for race application?

[R2 Racing]

I use the swepco gear lube with a limited slip additive in my 86 944 race car

[Matt Monson]

For a racecar, limited slip additive is defeating the purpose. Limited slip additives are a NVH thing. They make the gearbox more slick, which is counter to the function of the LSD, and in the instance of the 944 specifically with it's anemic little 2 plate LSD that barely locks when it's fresh and new, you're really handicapping yourself here.

And under no circumstances put an ATF in that gearbox. Use a proper GL5 rated gear oil intended for transaxles.

Regards,

Matt Monson
Guard Transmission LLC

[commdiver]

ATF is a msnmer as some old school guys clean there transaxles and engines by running them with ATF for a few miles as low RPM's and ONLY as a detergent!!!

If your transaxle is in good shape and it has not sat unused for 10 years I would not run ATF thorugh it unless you really want to waste 4 qts of ATF and then another 4 qts of gear oil as you need to then flush with cheap gear oil and drain before you do a final fill with good Red-line 75w-90 or Swepco 201