Intractable Speedo failure

[bmweerman]

About 20k mile or so, I'm obvioulsy guesing, my speedo failed.

 

New cable did nothing...replaced speedo drive..worked for exactly 180 miles. If one, as was suggested here, run the speedo cable round with and electric drill, the speedo registers...(my Black and Decker cordless goes about 12mph..does that mean I can countersteer with it? )

 

Anywhoooo...I've replace, torqued, untorqued, taken a trip, not taken a trip...you get the picture and nothing works.

 

Here are the pix

 

 

 

 

 

 

 

Any thought?

 

Thanks guys

 

Cameron

[Ken H.]

Well it's kind of hard to tell a lot with all that grease in there. Maybe clean it all up and re-post pics?

 

I think this ass'y is basically installed dry anyway.

[ShovelStrokeEd]

Just a thought.

 

Measure, by whatever means available to you, the length of the spacer between your wheel bearings. Compare that with the distance between the bearing seats in the wheel. It should be no more than a fuzz longer than that distance. If it is too long, you might not have enough room to accomodate the drive components as you tighten up the axle bolt. This will cause the internals of the drive to put a tremendous load on its small internal gears leading to early failure. You might also measure the thickness of the drive tang, comparing it with a new one.

 

I'll state the obvious just to cover all the bases, no insult intended, but you are sure you are properly engaging the drive with its tangs upon assembly, right?

[Chris K]

Randy Etheridge and I chased this same problem on his R1100RT. Ultimately we discovered the drive tangs were worn. It doesn't take much wear for this to happen. The part is cheap, under $2 if I remember correctly.

[DEF]

I have noticed lack of grease on some BMW speedo drives. As Ed suggests, make sure it’s clean and oriented correctly. Also, use plenty of grease and reassemble. But, your photos suggest the tangs may be shot shot. From what I see, a rebuild of the left hand side is in order...seal, drive and possibly the gear assembly. Your looking at the parts in person...you're the best judge.

 

After reviewing your photos again, it appears the gear in the drive assembly is gone. Recommendation as before, remove the left hand side, clean it up, and rebuild. Also, do not use moly grease in this application as it appears was done in the past. A regular wheel bearing grease is recommended here. Reason? If any moly grease is thrown from the hub, your brakes are worthless.

[bmweerman]

I think this ass'y is basically installed dry anyway.

 

Wow...really? I'm not arguing but the original one that came off was full of grease as was the replacement which actually was not new but came from beemerbonyard with 12k miles on it.

 

If they are installed dry where does all that grease come from?

[bmweerman]

I'll state the obvious just to cover all the bases, no insult intended, but you are sure you are properly engaging the drive with its tangs upon assembly, right?

 

he he good question...actually I did check but no offense taken believe me!

[Eckhard Grohe]

It looks to me like the drive washer is cupped toward the inside of the wheel suggesting that there was axial pressure on the tangs pushing them toward the center of the wheel assembly. That would make them effectively too short and unable to drive the gear or pop out after a while. Or perhaps that is an optical illusion..

 

As said before, clean up the parts and post the new pictures please.

[bmweerman]

Ok Echard...does this look like the offending piece/

 

Notice where I pointed with the photoshop arrow ...there is a deep groove worn here.

 

 

Sorry it's hard to see...got to get a camera with better macro.

 

Here also are some other, cleaner pix:

 

 

 

Is that in any way more helpful?

 

Thanks again...Cameron

[Mulepick]

Coincidentally, I was just in there replacing the fork seals. Can't say so empirically but your tangs look worn to me too. This after just buttoning mine up.

 

Bob

[bmweerman]

thanks for the response and just to be clear are we talking about the tangs inside the wheel itself?

[flars]

The plastic drive gear you are holding gets eaten up by the metal drive dog that sits in the wheel as a matter of time on some bikes - on others, it doesn't). You can see the drive dog sitting in the wheel with the two tangs poking out. (This little mother just sits in there behind the seal) My drive dog looked good...until I pulled the seal and then pulled out the drive dog. There are two tangs on the other side of that metal-washer-looking dog that engage two notches in the wheel hub. These two tangs were missing on my dog - as in chewed off completely. Cost is 84cents, I think. Try to turn the dog with your fingers or a pair of needle nose pliers with it sitting in the wheel. If it turns, the inner tangs are gone. Just pull the seal out and put a new dog in. I also made sure the tangs contacted the plastic gear cleanly by bending the out a little, but that only lasted a couple of thousand miles, so since the speedo drive came with a new one, I just replaced it. If you didn't get a new plastic drive part you can build it up with a little JB weld if you are cheap enuf.

[bmweerman]

Hey thanks for the input!

 

and

 

If you didn't get a new plastic drive part you can build it up with a little JB weld if you are cheap enuf.

 

 

who me

[Mulepick]

Yeah. The wheel tangs vs. the removable speedo tangs.

 

B