Speedometer gear replacement

Do I need to remove the rear transmission cover to change the speedometer worm gear?

I have not seen said gear, is it metal, pot metal or plastic?

Does it engage with the output shaft of the transmission? St.

From the diagram, it appears that it just comes straight out...sort of like how a distributor engaged with the older cars:

https://www.realoem.com/bmw/enUS/showparts?id=0333-USA-09-1977-2474-BMW-R_100_7T&diagId=23_0254

Better diagram

Hey Kurt, your picture is a whole lot better than the one at Max BMW.

I can see now how the gear works with the output flange.

Not happy about the Bite MY Wallet price for the new gear!

Thanks for the reply. St.

There are alternatives to your speedometer. GPS, Sigma bicycle speedometer, stopwatch/mile markers TSD mathematics are some that come quickly. Or just bite the bullet and order the gear if you are sure that is the problem as opposed to a broken speedo drive cable. The gear is easy enough to remove and obvious if it is stripped. Know anybody with a trashed tranny willing to give you their old gearbox speedo drive gear? I do believe they were all the same for the Airheads.

Friedle

What I have found so far.

So far:

Kurt was helpful in sending me a better diagram as to how the gear engages as well as pointing out it may detach like an old distributer. I have not had the time to try to see if this is true.

Drew from Max BMW was kind enough to tell me the gear is not plastic but is metal, he did not say however if it is a pot metal gear or a machined gear.

I could see a pot metal gear wearing out if engaged with a solid machined gear. Pot metal being better than plastic but still not a solid machined gear.

IF it is a pot metal gear, the price of almost $90 is Bite My Wallet, typical. I would be more understanding if it turns out to be a machined piece of metal.

I made no mention of problems with my system.

I did not ask about alternative systems, I am not interested in alternative systems.

I made no mention of a problem. I asked three questions. I AM smart enough to know if the cable is broken. St.

Steve, please let us know what the problem ultimately turns out to be.

Friedle

STEVENRANKIN said:

So far:


Drew from Max BMW was kind enough to tell me the gear is not plastic but is metal, he did not say however if it is a pot metal gear or a machined gear.


IF it is a pot metal gear, the price of almost $90 is Bite My Wallet, typical. I would be more understanding if it turns out to be a machined piece of metal.

I made no mention of problems with my system.


I made no mention of a problem. I asked three questions. I AM smart enough to know if the cable is broken. St.

Click to expand...

Hi STEVEN, It has been a looong time since I removed it but the gear on my '76 R90/6 was machined steel. BTW you also made no mention of which bike that you are working on but a check of the parts fiche would likely indicate that they are all the same ;>)

Russ '76 R90/6 '78 R80/7 '78 R100RS

gear

Ok, so far, the gear is not pot metal but a good machined piece.

It does lift out like a distributer as Kurt mentioned.

Inspection of the gear shows no wear as I would expect for a machined part, not pot metal or plastic.

I have an ongoing problem with a speedometer repair shop regarding a badly bouncing needle on my speedometer and a failure to address the issue after the speedometer was sent in.

Cable, cable routing, and gear are 100% OKAY. A speedometer from another bike is steady as a rock, as should be.

I am not going to discuss any issue regarding the shop as I am not 100% sure we have communicated properly. The fault in the failure to fix the problem may in fact be due to my miscommunication.

I thank those of you who responded to my post. St.

Speedometer guts

For my own education, I pulled apart an old speedometer.

Now I have a better idea as to why a needle can bounce around.

Now I just have to find someone to fix the problem. St.

Send it to Terry Vrla. He will fix it properly.

terryvrla@hotmail.com