Looking for synthetic advice

[jedimaster]

Actually, I need real advice about what synthetics to use in the trans and rear diff. I'm going to go with a synth for the trans and rear diff, but not sure what brands and viscosities to go with. Any advice?

[eatV8]

MOTUL FTW... Factory weights.

[jedimaster]

Really? Is that something I can get at Autozone?

[gargleblaster]

Be careful running synth in the tranny. Lotsa guys had problems with the WRX 5MT synchros when running synth - apparently it was too slippery for the synchros. Since the Legacy/Outback 5MTs are 'reinforced' WRX boxen, I'm guessing you'll need to follow some of those guidelines.

I believe what you're looking for is a synth trans fluid with friction modifiers. There was a really good thread about this over on the Cobb wrxforum a while back. I'll see if I can dig it up later tonite.

As for the rear diff, as eatV8 stated above, you should be okay with factory weighted synth of your choosing. I went with Amsoil and had good results. I'm sure Motul would be a fine choice as well.

[klaymon]

I had synthetic in my STi tranny for a short time and had synchro issues. I've gone back to dino and everything's cool again. There are guys that use synthetic without problems, but there are just as many with issues.

[Drift Monkey]

Specialty Formulations gots what you need.

Also - the Subaru dealerships around me have some new synth stuff that'll I'll probably go with this weekend...

[gargleblaster]

Ahh - that reminds me of a good product. Silkolene makes a tranny/gear oil that is friendly to the 5MT's synchros. A lot of guys in the Dallas area used it with good results. Heist was gonna run it in his GC8 at one time - not sure if he ever did, but they sell it at Subaru of Dallas' site:

http://hotsubarus.com/index.asp?PageAction=VIEWPROD&ProdID=146

[jedimaster]

Thanks guys- I ran synth in my WRX wagon (5MT) and it made a nice difference, particularly in the cold weather.

[john]

Redline is always a great choice.

[scans007]

+1 on the DM

http://specialtyformulations.netfirms.com/store/nfoscomm/catalog/index.php
Tranny and diff fluid:
MTL-R
Manual Transmission Lube GL4/GL5 – 75W90 (1 gallon)
HDS-5
Heavy Duty Synthetic GL5 Gear Lube 75W90 (One quart)

[STEye]

Personally, I am sticking with factory oil with my STi... I figure it works, why mess with it.. Just my .02