Author Topic: whats the best gear oil for transmission (Read 3963 times)

stereomotional · « **on:** November 29, 2008, 07:24:28 PM »

im swapping my trans, what gear oil is the best? im going to drain and fill the new one and im not sure what to buy. royal purple? valvoline?

txleadfoot · « **Reply #1 on:** November 29, 2008, 09:02:30 PM »

I use Mobil1 ATF.

stereomotional · « **Reply #2 on:** November 29, 2008, 09:14:41 PM »

for manual trans?

ak96ss · « **Reply #3 on:** November 29, 2008, 09:18:21 PM »

Many of the manuals use ATF - mine does. Should be a sticker on the crossmember under the engine.

P. Kennedy · « **Reply #4 on:** November 29, 2008, 09:41:39 PM »

Mine too. Wipe off the grimey sticker on the underside of your tranny and more than likely it will indicate ATF.

JP 91iS · « **Reply #5 on:** November 29, 2008, 10:54:21 PM »

Yeah the sticker should be red. Mine was on the underside of the transmission near the front.

I tried figuring out which was the best (here). Amsoil, Redline, Royal Purple all came out with pretty much equal popularity (amsoil slightly ahead). I think as long as it is a well known brand it will work fine. The deciding factor is cost.

I never got a good answer on whether to stick with an ATF or try one of the Manual fluids. Royal Purple Synchromax is for manuals that specify auto fluid. So.. I dunno. I think I'm going to go with Amsoil ATF.

318isfolife · « **Reply #6 on:** December 02, 2008, 10:56:24 AM »

can't go wrong with mobil castrol or redline. when i was at MMI all the teachers would talk about how amsoil is over rated. now i did go to school for motorcycles and a 318is is no motorcycle in anyway. but i know mobil and castrol have been around for a LONG TIME! so they must be doing something right

ajatya2 · « **Reply #7 on:** December 03, 2008, 12:38:17 PM »

I talked to some of the guys that race SCCA and they sware by Redline. personaly i havent delt with it. I use Royal Purple in my diff and Tranny. Id recomend that or moble1 and u cant go wrong with moble!

strad · « **Reply #8 on:** December 10, 2008, 03:41:37 PM »

The funny thing is, the owner's manual for my car specifies "reputable non-hypoid gear oil." But I do believe (not sure though) that the trans has that orange sticker on it. At any rate, I've been using MT-90 for a couple years now with no ill effects.

stereomotional · « **Reply #9 on:** December 10, 2008, 03:44:41 PM »

thanks guys!

crazzy_hippo · « **Reply #10 on:** December 10, 2008, 07:07:22 PM »

I am using Amsoil right now. Also tried Torco before. Both IMHO are better than Redline. Also tried Mobil gear oil. Its good as well. My transmission does not have an ATF label thus I am using 75W90 gear oil right now.

1991 E30 M42 · « **Reply #11 on:** December 10, 2008, 10:30:22 PM »

Royal Purple Synchromax, its made for manual transmissions that specify atf

"Synchromax is a manual transmission fluid that increases performance and the life of your equipment. It improves shifting, reduces gear noise and increases power transfer to the wheels. It also lowers operating temperatures and provides outstanding wear protection for longer transmission life.

Synchromax is recommended for manual transmissions that specify an automotive transmission fluid. It�s also ideal for 4�4 transfer cases and motorcycle gear boxes. Synchromax is fully compatible with all types of friction materials. It provides excellent corrosion and oxidation protection without affecting the soft metals commonly found in manual transmission synchronizers.

Synchromax is formulated with Royal Purple�s proprietary Synerlec technology for unsurpassed performance and protection."

"BMW Green label (SHC 630) arrowMax-Gear 75W90

BMW Red label (DEXRON III) arrowSynchromax

BMW no label (80W GL-4) arrowSAE 30 "