How to get new OEM shift knob to stay on?

[Vincent Brick]

I just put a Z3 1.9 shifter in my car with a new OEM mushroom knob, now every time I grab 2nd gear with any enthusiasm the knob comes off in my hand. The threads I found upon searching seemed to point to a worn shift knob, but mine is brand new, as is the shifter lever.



Is there a solution to this, or do I need to go back to my cheesy Pep Boys knob that has set screws? This is exactly why I've never ran an OEM knob previously, I guess my fears were justified. Everything about BMW shifters suck, my biggest gripe about these cars!



Thanks!

[earthwormjim]

You have to align the knob properly, then smack it down hard to get it to stay. Perhaps your brand new knob is already damaged?

I have a Z3 shifter and ZHP knob, no problems with it coming loose.

[E30SPDFRK]

You can squeeze the top of the shift lever slightly to make it grab the knob a bit better. But if your new parts aren't holding well, I too would say something is damaged; They should be stuck as well as if they were screwed together.

[BMW_325i]

I have had problems with gearknob coming off a Z3M shifter.

I have applied thick wall heatshrink to the upper section of the lever and the knob now stays firm.

[JimmyP]

What holds the stock knobs on is the plastic ring at the base of the knob that locks into the groove.
Its possible yours may be cracked and not locking into that groove. It should be quite hard to get off (like punch yourself in the face hard).
The slot holds its alignment from rotating, but the groove and the plastic ring holds it on vertically.
Maybe try another stock knob to compare to see if yours may have weak plastic ring?
IN the old days I have seen people get through a track day with a cracked plastic ring by putting a small hose clamp around the base of the shift knob.
Maybe try that and see if it improves. Have a look at the bottom of the knob and inspect that plastic ring. Its got slots to let it expand over the nub and a tapered "chisel" type profile to lock into that machined groove in the shifter handle.

That round groove is the whole of the vertical retaining method


Another possibility is the amount of enthusiasm,,, Hold the shifter like its a raw egg.
If you are pushing or pulling any harder than would crack a raw egg, you are doing it wrong.
FWIW I raced for years with a stock mushroom knob and it never came off once.
Hope that is helpful.

[tomstin]

Check the length of the shift rod and the depth of your shift handle. When I installed my short shift rod, the rod length is shorter (from the top to the wider part of the shift rod) than stock. I needed to cut my shift handle down so it would go all the way down. The boot and wider part of the shift rod was preventing the handle from going all the way down.

[Vincent Brick]

Soooooo I totally forgot I had made this post until yesterday when I started thinking about how much the shitty BMW shifter keeps me from having fun in my car..... not just the knob coming off but the sloppy feel no matter what I do to try and make it better, and bottom line I looked at your responses and the problem may as dumb as the zip tie I had holding the shift boot up with my old, smaller knob, causing the clip action at the bottom edge to not fully engage. I just did my best Ronnie Sox impression in the driveway and it didn't come off, where before it came off easily. Next time I go somewhere I'll get frisky and see if it stays put. Somehow I never noticed there was a clip action down there, thought the clip action was all in the notch at the top. If it comes off again I will try shrink tube or tape plus force.

Or I might just be shifting in a way that some may think is too hard. I grew up around drag racing, and it has always bothered me how I have never been able to nail a proper 1-2 powershift in this car, so I am kinda looking into what I need to do to remedy that. I bet this car would be so much quicker if I could shift it fast enough under high load to not lose so many revs, only really a problem on the 1-2, but BMW shifters and/or G260 just sucks so hard. No joke the shifters are part of the reason I don't want another BMW after this lol

Thanks for all the suggestions!