Manual transmission fluid recommendation

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Hi, I need help picking a MTF for a 1992 BMW 325is 5-speed. The manual says Dexron II. I can't decide between a Dexron III or a synchromesh transmission Fluid Any suggestions? -Thanks!
 

mva

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I am currently running Mobil synthetic ATF in my 2000 Z3M manual trany. Shifting improved over the stock fluid. Next change I am going to try Amsoil 5W30 MTF or Royal Purple Syncromesh fluid. There are number of BMW owners reporting very good results with Amsoil 5W30 MTF. Check out this thread for extensive information on this topic: http://forums.bimmerforums.com/forum/showthread.php?t=1076268
 

BimmerMan

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 Originally Posted By: Pablo
I'll probably use that next time, I want to change the oil today so I'll need something I can pick up locally.
 

BimmerMan

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I went with Redline MTL. It was $9.59 a quart at my local performance auto parts store. :) I'll let you know how it works out..
 
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I've always run Mobil 1 ATF in the Getrag in my 1995 ti. No complaints after 118,000 relatively hard miles on both road and track.
 
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I find that a lot of ATFs beloved by BMW fans who don't get technical about lubricants (ie. they believe that all 30 weights are the same) are very thin like Royal Purple Synchromax. My 4/98 528i with ZF 5-speed came with MTF-LT-1 and was revised to MTF-LT-2. I believe both of these are in the range of 9 cSt, while most ATFs seem to be 7 cSt. A good fit in that viscosity range are several of the synchromesh fluids like Redline MTL and Amsoil MTF. Over the years I have used MTF-LT-1, RL D4ATF, RP Synchromax, back to D4, RL MTL and Amsoil MTF. I believe I currently have play in part of the shifter mechanism that is extremely difficult to access so my "review" of my latest fluid MTF is probably not of much use. My choice from this bunch is MTL - a little thicker for the gear faces and bearings and designed for synchromesh (which not all ATFs are). The Amsoil MTF didn't seem any worse than MTL, but until I get my linkage perfect again I reserve judgement. Redline's recommendation for my transmission was D4 ATF, because anything thicker might get hard to shift in cold weather. They indicated the entire GL4 lineup (MTL, MT-90) were perfectly acceptable but they don't want to generate customer complaints from hard shifting in cold weather. I used MTL down to -20C and it was perfectly fine - better than the thinner fluids in fact. Unless Redline or Amsoil specifically do not recommend their fluids for you 92, I would give either a try. Redline has been a favourite recommendation of Bimmer magazine for drivelines for many years. I'm due for a swap this year and I haven't decided whether to stick with Amsoil or go back to RL.
 
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BimmerMan

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 Originally Posted By: Craig in Canada
I find that a lot of ATFs beloved by BMW fans who don't get technical about lubricants (ie. they believe that all 30 weights are the same) are very thin like Royal Purple Synchromax. My 4/98 528i with ZF 5-speed came with MTF-LT-1 and was revised to MTF-LT-2. I believe both of these are in the range of 9 cSt, while most ATFs seem to be 7 cSt. A good fit in that viscosity range are several of the synchromesh fluids like Redline MTL and Amsoil MTF. Over the years I have used MTF-LT-1, RL D4ATF, RP Synchromax, back to D4, RL MTL and Amsoil MTF. I believe I currently have play in part of the shifter mechanism that is extremely difficult to access so my "review" of my latest fluid MTF is probably not of much use. My choice from this bunch is MTL - a little thicker for the gear faces and bearings and designed for synchromesh (which not all ATFs are). The Amsoil MTF didn't seem any worse than MTL, but until I get my linkage perfect again I reserve judgement. Redline's recommendation for my transmission was D4 ATF, because anything thicker might get hard to shift in cold weather. They indicated the entire GL4 lineup (MTL, MT-90) were perfectly acceptable but they don't want to generate customer complaints from hard shifting in cold weather. I used MTL down to -20C and it was perfectly fine - better than the thinner fluids in fact. Unless Redline or Amsoil specifically do not recommend their fluids for you 92, I would give either a try. Redline has been a favourite recommendation of Bimmer magazine for drivelines for many years. I'm due for a swap this year and I haven't decided whether to stick with Amsoil or go back to RL.
Good post! \:\! Like I said, I went with Redline MTL. Seems to shift fine. Too early to tell if the shifts are smoother, I've only driven it two miles...
 
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 Originally Posted By: BimmerMan
Good post! \:\! Like I said, I went with Redline MTL. Seems to shift fine. Too early to tell if the shifts are smoother, I've only driven it two miles...
I think you'll probably be happy. I felt it was improved over D4ATF when I backed out of my driveway for the first time (nicer 1-R-1 shifts even when cold) :) I change all of my fluids at 2 year intervals (I try for 1yr on the brake fluid and sometimes let coolant go to 3years). I only drive ~15,000km in a year, so I'm changing more often than I HAVE to. Nevertheless, I always feel improvements when going to fresh fluids in all applications except coolant (nothing to feel there). The rear end is always quieter after service, the transmission shifts better, the brakes feel better etc...etc... When I comment on the fluids I'm trying to compensate for the fact that fresh anything may have felt better than the D4ATF I drained, but it had <30,000km on it so still should have had some life left in it. :) A lot of people make that mistake - "I changed to blah blah and it so much better than the blah blah I was living with for the last 100,000miles". As I said, fresh anything would feel/work better than the 100k old fluid that was in there, no matter how good it was.
 
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OK, you, like me, have a manual tranny that calls for ATF. I would run a full synthetic ATF like M1 or RL, or, I'd run RP Synchromax. Synchromax is a special gear oil that is specifically designed for manual trannys that call for ATF. Your manual tranny wants ATF because it is designed for a thinner lower viscosity oil. Don't listen to those guys who are telling you to put in a thick gear oil. In my old WC T5, I'm running a 50/50 mix of M1 ATF and Synchromax. Shifts great.
 
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I don't think it was designed for anything. Simple movement toward MPG by most automakers since they don't care how long a vehicle lasts. When they bring up the MPG vs wear charts vs warranty and play statistics..... who do you think benefits? Isn't MTF-LT-3 the latest spec from BMW??? Rumor is that its good for another 1% MPG!!! At what cost? With the typical warmer weather in California, you probably won't notice a slightly thicker MTF/MTL vs DexronII. For someone in Canada, thicker fluid can negatively affect shift quality, especially prior to the fluid warming up. Problem with new ATFs, like M1, RP, RL, Amsoil, is that they moved toward universal or multivehicle spec's, which IMO are not optimum for manual transmission shift quality. This is where you would want to hunt for a synth fluid that isn't universal, like Amsoil ATD, Redline Synthetic-ATF(not the D4), RP Syncromax, and some synth type-F or TES295 substitutes. And, you won't have it easy finding normal mineral obsolete DexronII at the local auto parts store!
 
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Good point unDummy. What is different about the innards of modern trannys and transaxles? I've yanked a good number apart over the years and don't see anything special in materials /clearances/preloads. ATF is OK'd in many cases now. But new trannys are not actually designed for it. ATF makes it cheap and simple at a dealership. Only one fluid for power steering, auto trannys, manual trannys and transaxles, and transfer cases.
 

BimmerMan

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Shifts are wayyyy smoother with Redline MTL. But, I'm comparing that to the old ATF that was in there. I don't think I'll go back to ATF. :) Ever...
 

BimmerMan

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 Originally Posted By: unDummy
I don't think it was designed for anything. Simple movement toward MPG by most automakers since they don't care how long a vehicle lasts. When they bring up the MPG vs wear charts vs warranty and play statistics..... who do you think benefits? Isn't MTF-LT-3 the latest spec from BMW??? Rumor is that its good for another 1% MPG!!! Yeah, and it's only $30 a liter... With the typical warmer weather in California, you probably won't notice a slightly thicker MTF/MTL vs DexronII. Nope, I don't notice.. Problem with new ATFs, like M1, RP, RL, Amsoil, is that they moved toward universal or multivehicle spec's, which IMO are not optimum for manual transmission shift quality. This is where you would want to hunt for a synth fluid that isn't universal, like Amsoil ATD, Redline Synthetic-ATF(not the D4), RP Syncromax, and some synth type-F or TES295 substitutes. And, you won't have it easy finding normal mineral obsolete DexronII at the local auto parts store!
 
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 Originally Posted By: Tremo
OK, you, like me, have a manual tranny that calls for ATF. I would run a full synthetic ATF like M1 or RL, or, I'd run RP Synchromax. Synchromax is a special gear oil that is specifically designed for manual trannys that call for ATF. Your manual tranny wants ATF because it is designed for a thinner lower viscosity oil. Don't listen to those guys who are telling you to put in a thick gear oil. In my old WC T5, I'm running a 50/50 mix of M1 ATF and Synchromax. Shifts great.
Since this was in response to my post, I'll respond.... It isn't speced for ATF. It's speced for MTF-LT-2 and most people use ATF. The entire MTF-LT-x series is ~9cSt, which is at least 2cSt thicker than all of the ATF wonderdrugs companies are pushing. I *have* run Royal Purple based on all the hype in certain BMW circles and it wasn't impressive. Amsoil MTF, Redline MTL and others are 9-ish cSt fluids that are right in the same range as MTF-LT-x.
 
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