BMW tranny and Synchromesh?

[e36'n]

Craig - I've tried RP Synchromax and it did not get along with my tranny at all. Grinded easier than any fluid I've tried. I'll update after I drive with the MTL for a bit.

 

[Craig in Canada]

quote:

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Originally posted by e36'n:
Craig - I've tried RP Synchromax and it did not get along with my tranny at all. Grinded easier than any fluid I've tried. I'll update after I drive with the MTL for a bit.

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In E39 circles everyone runs around professing the amazing powers of RP Synchromax. While I'm not nearly as enthusiastic, I feel that it's the most synchro-sticky fluid I've used so far. Whether I feel it's right for my car is outside of that observation.

Are you sure that your clutch isn't dragging and causing the problem? I don't know how you can be grinding every shift unless either your clutch or transmission is toast. You should not be having this many issues finding a fluid that works, and fluid may simply not be a fix to your problem.

Actually, on re-reading your original post, your CLUTCH *is* screwed. Shifting from N-to-1 doesn't cause grinding unless your clutch isn't disengaging fully - period. Sorry I didn't pick up on this days ago.

Craig.

 

[Jim 5]

Please PM me if you're ever planning on being in the Calgary area and you want to show off your turbo 325is to another BMW fanatic.

I'd love to get a look at that engine, and see how it performs.

 

[e36'n]

quote:

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Originally posted by Craig in Canada:
In E39 circles everyone runs around professing the amazing powers of RP Synchromax. While I'm not nearly as enthusiastic, I feel that it's the most synchro-sticky fluid I've used so far. Whether I feel it's right for my car is outside of that observation.

Are you sure that your clutch isn't dragging and causing the problem? I don't know how you can be grinding every shift unless either your clutch or transmission is toast. You should not be having this many issues finding a fluid that works, and fluid may simply not be a fix to your problem.

Actually, on re-reading your original post, your CLUTCH *is* screwed. Shifting from N-to-1 doesn't cause grinding unless your clutch isn't disengaging fully - period. Sorry I didn't pick up on this days ago.

Craig.

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I agree that most e36 BMW owners that I've talked to love RP Synchromesh. Mine has the Getrag transmission, which may or may not make a difference.

I'll have to look into the clutch issue, although I really think that it engages fine. The only time it grinds is going quickly from neutral to 1st or when I'm trying to rush 5th.

The only fluid I really experienced excessive grinding with was RP. Although few, I have heard a couple e36 owners say the same thing as me. Whether the 1st gear synchros are already gone or not, I'm not quite sure.

Jim 5 - definitely will do. I'm still tuning, or should I say trying to tune it up properly. The 92's didn't have knock sensors and I'm having some detonation problems. It's a work in progress, but worth every cent and second.

 

[Craig in Canada]

e36'n: E39 540s have Getrags. E39 528s like mine have ZF. It's mostly the Getrag boys that rave about RP Synchromax.

It's not that your clutch doesn't engage, it's that it doesn't fully disengage. This can be for a variety of reasons, including wear. Your symptoms describe PERFECTLY the symptoms. How could your choice of fluid affect grinding from N-to-1 at a standstill otherwise? The synchros should be doing NOTHING when you're stopped and the clutch pedal is pressed.

I believe the factory test is something like this:

With the car stationary in neutral, clutch in, attempt to shift to first. If it hesitates or grinds - take note. Now from neutral push gently against the synchro resistance and with the other hand shut off the engine. If it slips right into gear, replace the clutch.

Obviously these aren't the exact words and don't communicate how hard to push against the synchros during the test, but try a couple of variations and report.

Again, I strongly suggest you stop shopping for fluids and check out your clutch before all of your synchros are shot.

Craig.

 

[e36'n]

So I've driven a couple hundred km's now and have some feedback.

I did the clutch test Craig recommended and it would not go into gear. Tried numerous times Also, 1st isn't grinding at all.

The Redline MTL feels thicker than the D4ATF although it doesn't shift as smoothly. Much better than Synchromesh though.

Thinking about it, I'm not sure why RP Synchromax didn't work for me. I'm starting to believe that my transmission likes a slightly thinner fluid than MTL, but I need something that will provide extra protection since it's 14 years old.

I'd like to try SF MTFGlide, but shipping to Canada will be $20 or so. Maybe I'll mix some D4ATF or Synchromesh or even just leave it in there for the time being. It's interesting to know that I can notice how the thickness of a fluid affects the shifting.