» Site Navigation | | » Recent Threads | | | | | | 02-07-2012, 06:44 PM | #1 | Senior Member Join Date: Oct 2008 Location: Los Angeles, CA Posts: 1,464 | Gear Oil vs. ATF I've seen a lot of back and forth on a few forums (including this one) about what type of lubricant to use in the gear box. It's a Getrag 5-speed, and I've seen that BMW recommends D4 ATF, but I've also seen a number of people put gear oil in them as well. In my experience, when a manufacturer recommends ATF in a manual gearbox, it usually means that there are friction surfaces on the synchros (not unlike an automatic trans.) that necessitate the use of ATF over gear oil. Is that the case here, or is ATF specified because of its lighter weight and/or detergent properties? (many Japanese cars use motor oil in the gear box as a lighter weight substitute for gear oil). The gear box has a little bit of slop in it (130k miles) so my reasoning was to put something thicker in it like gear oil (I live in So. Cal., so sluggishness in cold weather is not going to be a big issue) but not if I'm going to cause damage to the transmission or somehow prevent it from operating like it was intended from the factory. Any help/insight on this is greatly appreciated. Thanks! | | | 02-07-2012, 07:09 PM | #2 | Junior Member Join Date: Aug 2011 Location: CA Posts: 6 | A transmission is one of the places where I would definitely go with the manufacturer recommended fluid. That's like using hydraulic oil instead of motor oil in the crankcase. Will the engine turn over? Sure. Will it screw it up later? Maybe. Why play the guessing game really. I know it's an extreme example, but one nonetheless. Just use what the manufacturer recommended, which is ATF in this application. BMW paid big bucks to their engineers to decide what's best. | | | 02-07-2012, 07:42 PM | #3 | Senior Member Join Date: Jan 2008 Location: New Orleans Posts: 970 | Quote: Originally Posted by trooper001 Just use what the manufacturer recommended, which is ATF in this application. BMW paid big bucks to their engineers to decide what's best. | not necessarily, bmw used atf in their manual transmissions because they were easier to shift, its a smoother feel, bmw had a bulletin about people complaining of hard feeling shifters and the fix on the cars with MTL from the factory was to put ATF in it Use RedLine MTlL, weve been using it since the 80s on tons of bmws and never had a problem, it does feel a little different but if the oil is old, it might make it feel smoother in some cases, also wouldnt hurt to redo all the bushings in the shifter mechanism if it feels sloppy. EDIT: DONT use Hypoid oil (stinky 75w90 differential/gear oil)...its been proven to eat synchros over the years __________________ ^being rebuilt^ until then: daily car: 96' Blue DASC'd ti with koni coilovers slowly progressing... weekend car: 85 1/2' 944 Porsche no a/c, p/s, gutted cat, loud as hell exhaust, loud as hell sound system Last edited by minicoop900; 02-07-2012 at 07:45 PM. | | | 02-07-2012, 08:18 PM | #4 | Junior Member Join Date: Aug 2011 Location: CA Posts: 6 | ^Didn't know about that bulletin, but that still goes back to what I said earlier. Use what the manufacturer recommends, be it what's on the service manual or an updated bulletin And I second the suggestion of not using Hypoid oil. Stuff is harsh in a gear box with certain metals. | | | 02-07-2012, 08:27 PM | #5 | Senior Member Join Date: Apr 2007 Location: Elizabeth City, NC Posts: 3,877 | Early cars had ATF spec'd, later cars had MTF spec'd. Not really a specific year, there is a sticker on your transmission that says which to use. On my '98 MTF is specified. Once you know that it becomes what brand of fluid to use. __________________ ~Dave~ 98 328ti Morea Grun slicktop 11 128i space gray slicktop 13 JGC WK2 Deep Cherry Search | RealOEM | | | 02-07-2012, 08:28 PM | #6 | Member Join Date: Feb 2010 Location: pa Posts: 45 | bmw recommends dexron3 atf in the manual 5 speed transmissions. you can use any dexron fluid that supersedes 3 such as 4, 5, and 6. i just checked mine for the first time after driving 50,000 miles and there wasnt much fluid left but i filled it with dexron6 and its alot smoother now. sticking with the oem spec fluid is the best thing for the transmissions in our cars. | | | 02-08-2012, 12:22 AM | #7 | Senior Member Join Date: Apr 2007 Location: Elizabeth City, NC Posts: 3,877 | Again, there is a sticker on the transmission that tells you what type of fluid to use. Supposedly the changeover was 9/97, after that the factory fill is supposed to be MTF-LT-1 for both the Getrag and ZF manual. __________________ ~Dave~ 98 328ti Morea Grun slicktop 11 128i space gray slicktop 13 JGC WK2 Deep Cherry Search | RealOEM | | | 02-08-2012, 01:09 AM | #8 | Senior Member Join Date: Oct 2008 Location: Los Angeles, CA Posts: 1,464 | Mine has a build date of 2/97, but I wanted to order the fluid and have it before Friday, as I was planning on changing fluids this weekend. I won't have an opportunity to get underneath the car to verify the sticker before the weekend. I guess I can just do the crankcase and differential and save the transmission for another time... Speaking of the differential- it's a brand new, small case LSD- is it better to use the BMW SAF-XJ +FM or is Redline oil w/FM ok? I know some diffs. are very particular about the type of friction modifier used. I usually order Redline oil on Amazon- great price, no tax, and I have it on my door in two days. Last edited by zoner; 02-08-2012 at 01:16 AM. | | | 02-08-2012, 02:59 AM | #9 | Senior Member Join Date: Apr 2007 Location: Elizabeth City, NC Posts: 3,877 | The SAF-XJ is supposed to be the best but Redline has a good rep too. I've used Royal Purple, Amsoil, and Mobil 1 and I like the Mobil 1 the most out of the 3, it kept the LSD quietest. The Amsoil caused diff chatter like crazy in parking lot situations. I'll probably try Redline next. __________________ ~Dave~ 98 328ti Morea Grun slicktop 11 128i space gray slicktop 13 JGC WK2 Deep Cherry Search | RealOEM | | | 02-08-2012, 07:08 AM | #10 | Junior Member Join Date: Nov 2011 Location: Canada Posts: 12 | where would I find sticker on my trans? I have a 97 and would feel bad if I ruined something by putting incorrect fluid in something I drive daily. I have looked and didn't find any sticker to indicate fluid choice | | | 02-08-2012, 07:08 AM | #11 | Junior Member Join Date: Nov 2011 Location: Canada Posts: 12 | where would I find sticker on my trans? I have a 97 and would feel bad if I ruined something by putting incorrect fluid in something I drive daily. I have looked and didn't find any sticker to indicate fluid choice | | | 02-08-2012, 08:19 AM | #12 | Senior Member Join Date: Oct 2008 Location: Los Angeles, CA Posts: 1,464 | Quote: Originally Posted by zoner Mine has a build date of 2/97, but I wanted to order the fluid and have it before Friday, as I was planning on changing fluids this weekend. I won't have an opportunity to get underneath the car to verify the sticker before the weekend. I guess I can just do the crankcase and differential and save the transmission for another time... Speaking of the differential- it's a brand new, small case LSD- is it better to use the BMW SAF-XJ +FM or is Redline oil w/FM ok? I know some diffs. are very particular about the type of friction modifier used. I usually order Redline oil on Amazon- great price and I have it on my door in two days. | EDIT: Checked the owners manual when I got home and it spec'd ATF. I also read that the fluid spec. changed in early 1997, but after my production date. Ordered 2 qts. of Redline D4... will post results after the change. | | | | Currently Active Users Viewing This Thread: 1 (0 members and 1 guests) | | Posting Rules | You may not post new threads You may not post replies You may not post attachments You may not edit your posts HTML code is Off | | | |