5th gear fix? Could it be this easy?

[Jgent]

Received the folowing reply from Jim at performance gearing on the sticking 5th/ loss of the 3rd & 4th gate.

"I assume that the problem you are having has to do with the decrease (or loss) of spring load to the shift lever from
the 3rd/4th galley neutral (rest) position, the following is an answer to someone who was having this problem.
If this is not the case, please advise.
The resistance in neutral position from the 3rd/4th galley to 5th galley is controlled by a spring loaded
"piston" that rides in a very close tolerance sleeve. Since the proper load returns after the car is
driven for a time, it might be that this piston is seizing enough to overcome its return load until
the aluminum transmission housing has warmed/expanded to the point that clearance between the
piston and its bushing returns.
You can access this assembly externally from the passenger side of the transmission, near the top
where the bell meets the main body. There are three 20mm seal plugs (usually blue), one of which is
recessed, the other two are nearly flush with the surface. The bottom one of these two plugs is the
spring landing for the piston ( the top one is for reverse load). Using a small flat blade screwdriver, tap it
hard enough to pierce the plug (obviously you will need a new one before you are finished), remove the
circlip, then , as you cup your hand over the plug, work the screwdriver handle back and forth until it and
the spring release. The only thing left in the bore is the piston, which should slip right out. If not, you
have found the problem. Taking care not to damage the plug sealing surface, twist and pull on the
piston ( for example, with a wooden dowel or large screwdriver) , and when it is out, work on the bushing
with some light emery cloth. Make sure the surface of the piston is clean, shiny and well lubed as you
check the bushing for clearance ( transmission as cold as possible), until it moves freely.
When reinstalling, make sure the piston is well lubed and inside bevel is pointing toward the top plug.
Insert the spring, then use a deep socket to drive the plug in just far enough for the circlip to seat fully.

Jim
Blanton Transmissions
1427 W. 9th Street, #202
Kansas City, MO 64101
816-221-8584 "

Wonder if this works and if you have to drop the transmission for access. Almost seems too easy especially as BMW is opting to replace the whole transmission to fix the problem

[Bernman]

Yes. This is the fix. The question that remains is will it be possible without removing the transmission...

[Ollie]

That sounds reasonable. BMW seems to have a policy when a car's transmission exhibits any sort of issues they just replace it, regardless of the warranty being in place or not. Then they send the troublesome unit back to be refurbished.

You'll be hard pressed to find a dealer mechanic who has cracked a BMW transmission for repair or rebuild. This is a "print off" message for me, for sure. My '99 does not exhibit this at all but in case it does at least I'll have this to fall back on.

[///M3 2 NV]

I'm sure that is the problem and the fix. That is what I talked about last week after my mechanic and I looked at a transmission that was on the bench.

The only remaing question is whether you can access the plugs without removing the transmission. :dunno

[Jgent]

Be nice to find a junk transmission to try this to see what the process is like.

Other issue I see is that the condition occurs in varying degrees with temperature at least it does on my car. Around 40 degrees the fifth gear gate becomes sticky. At temps in high teens/ low twenties the shift lever is firmly held under the 5th gear gate with no 3rd/4th gate. To do this fix one would almost want the transmission at low temperatures so one could assess what size the bushing has to be cut down to.

Other thing is the condition appears to get worse over time, so something must be wearing, or building up on the bushing to cause the stiction (changing oil seems to have had no effect with other people) or the spring is becoming weak... Spring weakening seems unlikely. Also wonder if the plug can be replaced with some time of piece with a threaded center bolt that can be used to adjust the spring tension.

[JasonJ75]

I would imagine you want the tranny fairly warm so you can pull the plunger, but dead cold when you replace it....

Also, is this plunger lubed by the tranny fluid?