Transmission oil type?

[930 porsche]

On 930 what type of transmission fluid should I use when changing oil? Your recommendation will be very helpful.

Thank you.

[JFairman]

If you don't mind the price swepco 201 is very good and seems to be the usual internet flavor of the month.

plain old inexpensive nothing fancy non synthetic valvoline GL5 is also very good and thats what everybody including the race teams used back in the seventies and eightees.

it doesn't have to have green, blue, or red dye in it to work.

[930 porsche]

JFairman, no I do not mind about the price. How much do I need for a total oil change?

[JFairman]

A gallon or 4 quarts.

You'll have around 4 or 5 ounces left over when the transaxle is filled to the bottom edge of the fill port with the car level.

[930 porsche]

JFairman,

Thank you for responding so promptly.

[saurkraut]

How about Redline 80-90 GL5 synthetic?

I have had good results in VW and Audi transmissions with their GL4 synthetic.

[sand_man]

Yep, Swepco 201, is all I have ever used. And you'll have a bit left over if you buy the gallon size (I always get it from our host). Also, be sure you loosen the fill plug on the tranny case first, before the drain plug! Sure would suck to drain the fluid, only to find out the fill plug is seized/galled and you can't drive the effin' car!

[JFairman]

Originally Posted by saurkraut

How about Redline 80-90 GL5 synthetic?

I have had good results in VW and Audi transmissions with their GL4 synthetic.

Synthetic gear oil is good for the gearsets and bearings but the Porsche steel synchros don't work well with it and they will wear out faster if you use it.

I've used Redline synthetic GL4 for limited slip diffs in BMW differentials with a ZF limited slip carrier that is exactly like the Porsche unit only smaller with only 2 clutch rings instead of 4 and that worked fine, and I've used Redline MTL in BMW transmissions and it worked really well, but BMW Getrag transmissions have used Borg Warner brass cone type synchro rings since 1972 or earlier in the 2002 and synthetic is fine with those synchros just like its fine in the Porsche Getrag G50 transaxles with brass Borg Warner synchros.

[panel]

Don't know if this will help you out........

http://forums.pelicanparts.com/porsche-911-technical-forum/490399-ultimate-transmission-oil-thread.html

[DonE]

Originally Posted by JFairman

Synthetic gear oil is good for the gearsets and bearings but the Porsche steel synchros don't work well with it and they will wear out faster if you use it.

[snip]

Synthetic lube doesn't work in these old things mainly because the synchros weren't designed for the lubricity synthetic offers. The synchros don't wear out - they need some small amount of friction to work and synthetic does not allow it (they seem like the wear out because shifting becomes very poor).

I use SWEPCO 210 which is 90w140 I think. I use it because it works and I haven't had to rebuild or work on my tranny even with the HP I have and all the DE's I've done.

[ertech]

If your car is a 89 or with a g50 swepco is not recomended

[JFairman]

The porsche steel synchro rings and brake bands will wear faster using synthetic because they will be slipping more and not gripping smoothly and engaging if you use them... and time adds up.