4-speed

IS3FIFTY

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Can the 4-speed on my 2800CS be rebuilt by any transmission shop or is too tricky for these guys and it is better to take it to a BMW specialist?
 

Tierfreund

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Much simpler and cheaper to pick up another used one.

You´ve got a choice of the ZF (2800 and early 3.0) or the Getrag 262. Both can be had for a dime a dozen. The getrag is basically indestructible. The ZF is noisy by design.
If you swap from one to the other you may need shifter arm parts as well, but everything else is compatible.
Finding someone to rebuild the ZF would be difficult, costly and you may be disapointed with the result.
The shifter feel of the ZF is very nice but, especially when warm, it makes noise like a bag of bolts. The reason for both (the good shifter feel and the noise) is the integrated shifter arm without the rubber elements that the shifter arm of the getrag has.

Once you´re swapping, it´s worth thinking about the 5 speed OD getrag though. Makes the E9 much nicer to drive on the highway due to reduced noise, consumption and wear.

What´s the problem with your current box?
 

IS3FIFTY

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the bearing, I suppose...

What´s the problem with your current box?
Current box is a Getrag and it sounds like the bearing is out (loud rattling when the clutch is not engaged, goes away when clutch is depressed). Other than this, it shifts fine. That's why I thought I'd take it to have the bearing replaced.
 

Stevehose

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Does it also make noise when driving? If it is the input shaft bearing at the front, replacing it shouldn't be too difficult as it is explained in the manual, the issue is finding the bearing puller that is long enough to go over the shaft - they're very expensive. The bearing is still available and if a BMW shop has the puller it wouldn't break the bank like a rebuild would.
 

m_thompson

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Current box is a Getrag and it sounds like the bearing is out (loud rattling when the clutch is not engaged, goes away when clutch is depressed). Other than this, it shifts fine. That's why I thought I'd take it to have the bearing replaced.

Mine did the same thing. Long before 5-speeds were available I had it rebuilt by Metric Mechanic.
 

MMercury

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Can the 4-speed on my 2800CS be rebuilt by any transmission shop or is too tricky for these guys and it is better to take it to a BMW specialist?

Would you let “any” paint and body shop paint your car, or anyone who calls himself a “qualified” mechanic, rebuild your engine? (One supposes that there may be a budding Rembrandt quietly working out of his one-lightbulb-and-two-screwdrivers- garage, but that would be the exception and not the rule.) “Any transmission shop” hardly describes a shop’s caliber, competency and resourcefulness.

The shop manual suggests that a Getrag R&R is something anyone can accomplish with rudimentary mechanical aptitude and a couple of hand tools. With experience and the right parts, this is probably true. However, how many reliable mechanics are around that work or have worked on manual transmissions, including Getrags? They certainly exist, but there is probably more demand for “Specialists” who remove and install automatic transmissions and pan gaskets, than rebuild Getrag 4-speeds. Installing a torque converter or a seal on a ‘92 Camry is not the same thing as shimming a 40-year-old transmission’s input shaft. Nor does it consider whether the shop has on hand any of the specialty tools commonly used for a Getrag rebuild and, most important, the shop’s ability to source replacements for questionable parts on a 40-year-old transmission. Unfortunately, this is also probably true for a shop that labels itself a “BMW specialist.” Most dealerships would probably avoid working on anything too old like your transmission. Carl N., in your neighborhood, and Metric Mechanic, are two likely exceptions.
http://www.metricmechanic.com/catalog/ultimate-transmission-part-1.php

You did not ask whether finding a used transmission for a swap would be better. This would make sense, especially given the cost of labor. Unfortunately, you cannot always judge a transmission by its cover. Your current transmission may have a spotless exterior and clean gear lube and no filings on its magnetic drain/fill plug/s. It may even turn smoothly by hand and shift smoothly. Yet, without tearing it down for inspection or installing it and testing it in a vehicle at operating temperature, worn bearings, chipped gear teeth, bent forks may go unnoticed. Even a low-mileage transmission that worked perfectly when it was removed, can be mishandled and after sitting too long on the basement floor can develop internal rust or corrosion. So even when trusted seller offers you the used transmission for a great price, what happens when you go to the trouble of installation only to discover a new unwanted issue?

Despite all of the above cautions, the noise you hear is probably related to the bearings on the input shaft
(e.g. 23121204580) and/or the layshaft. Both bearings are available. For someone who has worked on Getrag 4-speeds, this is highly doable. "Specialists" routinely rebuild the ZF 6-speeds and Getrag differentials found in some Corvettes http://www.rsgear.com/products/transmissions/race-performance/c5.aspx , but finding one to work on your transmission may be difficult and not inexpensive. Nevertheless, this does not guarantee against finding other internal parts that deserve replacement. Mechanics who intend to remain in business would have difficulty replacing just mainshaft bearings, knowing that the synchros are very worn (but functioning), due to the likelihood of future repairs.

You might be able to nurse the transmission by switching to a heavy gear lube. This may quiet things down, but result in greater shifting effort and less effective and possibly even advanced synchronizer wear. Worn parts usually do not repair themselves. When a bearing cage disintegrates, or you loose a bearing, hopefully the mechanical debris will fall to the bottom of the case or stick to the magnetic fill plug without kissing the gears. For all of the potential aggravation and cost, you might want to carefully consider the 5-speed conversion.

Hth.

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steve in reno

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I agree with all of the responses above.
Are you sure that it is the trans making all of the noise?
A very likely cause could be the throw out bearing. Which would give all of the symptoms you noted.
Have you checked and changed trans fluid with thicker viscosity? Does front seal leak? Getrag's are very strong but are now old.
reno
 

Stevehose

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The throw out bearing would make a noise when the clutch is pressed, when not shifting the bearing is not engaged. It could be the pilot bearing though.

I agree with all of the responses above.
Are you sure that it is the trans making all of the noise?
A very likely cause could be the throw out bearing. Which would give all of the symptoms you noted.
Have you checked and changed trans fluid with thicker viscosity? Does front seal leak? Getrag's are very strong but are now old.
reno
 

G-Man

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Recommend you take your gearbox to Bill Holmes shop near Ramona if you want it rebuilt. Bill rebuilt the ZF 4 speed in my 2800 and it runs much quieter now. Bill works exclusively on old school BMW's, his shop is in the middle of nowhere off SH 67 (Mussey Grade Rd). 760-789-2002 is his shop's #, Carl N can give you directions to Bill's shop. I second the others that it would be cheaper to go with another 4 speed or even better yet, try to find a getrag 265 five speed but they are getting harder to find. The problem is, finding a good 4 or 5 speed in decent conditions these days is a roll of the dice. Used gearboxes are over 30 years old.

G-Man
 

IS3FIFTY

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LF: 4 speed in good condition.

Thanks everyone for your valuable input.
I guess that I'm now looking for a 4-speed in good condition. Any leads are welcome, preferably in San Diego/Southern California.
G-Man, thanks for Bill's address... I'll save him as my backup plan.
 
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