Speedometer rattle on R80 RT

[msw0530]

Hi all --

First post here so be kind to the rookie ...

I took my 83 R80 RT out of storage this spring and took her for a spin. All running smoothly (slight squeak on the front rotor - probably a caliper adjustment) but my speedo has been acting funny. Seems to be behaving normally but then I hear a rattle up front somewhere and the needle will go dead, and then re-engage.

The cable is solid and the bushing is fine where it connects to the transmission (or at least I'm trying to avoid disconnecting it there) so I'm wondering if this means the speedo itself is gone. As I say, it sounds like a rattle up front, and then the needle drps to zero while riding, but then it comes back to life.

Can't find anything in my Clymer manual about the speedo AT ALL, so hoping somewhere here has solved a similar issue somewhere along the way. Thanks in advance -- looking forward to connecting.

[Kurt in S.A.]

Welcome! My guess is that the internal part of the cable is beginning to fray. The frayed ends are catching, then not catching, etc. You really don't want that kind of activity on the needle...it will likely do internal damage. You could try lubricating the cable by undoing both ends and then getting some lube in there...I like Tri-Flow...might find it at bicycle shops. Probably should consider getting a new cable...they really don't need lubing but in an emergency...

Be careful about damaging the internals.

Kurt in S.A.

[Rob Frankham]

As Kurt says, probably the cable. It may be frayed or it may be wear to the squared end where it fits into the drive. If the cable is old, it might just be time to renew it anyway. even if it looks OK. There is one other thing that might be worth trying. If you remove the instruments from the bike, it is reletaively easy to test the speedo. Use a file to square a section of a nail, then remove the head and fit it in an electric drill. It needs to be reversible because the drive is anticlockwise.you can them spin up the speedo to see if the noise occurs. If it does, it isn't the cable... The next thing is to look at the drive gears inside the speedo. This means the speedo head wioll have to be taken out of the case but that's no great problem. The drive gears are in the plastic moulding at the rear of the speedo. Just two screws to remove it but be careful. The moulding also holds the rear bearing for the speedo drive so, with the moulding removed, the needle and drive ar unsupported.

[msw0530]

Thanks to both of you! My Clymer is pretty useless when it comes to how to disconnect the cable at the tranny case and I don't want to force it -- any advice? I think I'll just replace the cable to be safe. Thanks again!

[Seth]

Take the vent bolt out of the trans case just below where the cable enters. Don’t lose it or use a regular bolt. It has a hole down the center to vent the trans and a nose below the threads to hold the cable housing in the trans. I think the head is 10mm. It also generally attaches the ground cable from the battery.

[msw0530]

Thanks!

Looks like I need to upgrade from my Clymer -- any recommendations welcome ..

Take the vent bolt out of the trans case just below where the cable enters. Don’t lose it or use a regular bolt. It has a hole down the center to vent the trans and a nose below the threads to hold the cable housing in the trans. I think the head is 10mm. It also generally attaches the ground cable from the battery.

[Kurt in S.A.]

I've never had a Clymers...been referring to my Haynes for a long time. That said, they are all fraught with errors! Even BMW's shop manual! Get a couple of manuals and bounce them off each other.

Kurt in S.A.