Erratic Speedo

[jmel]

I have a mechanical VDO speedo, and its always been very steady up until a couple of days ago. At a dead stop, it said i was doing 20, and was all over the place while driving - when doing an estimated 40-45mph, it said i was doing anywhere between 30 and 75, just bouncing all over.

I checked connection into speedo, and connection at tranny, and all is well. I pulled out the cable looking for binds or frays, and there were none, however it was a bit on the dry side. I greased it up all nice and purdy like, put it back in, and apparently thats the cheapest mod you can make to a car, cause i was doing 90-100+ all the way home.

The ol' roadster sure is steady at those speeds.

In short...what the hell should i be looking for? Not exactly sure what is causing this. Is speedo bad?

 

[cantwell.colton]

I have a mechanical VDO speedo, and its always been very steady up until a couple of days ago. At a dead stop, it said i was doing 20, and was all over the place while driving - when doing an estimated 40-45mph, it said i was doing anywhere between 30 and 75, just bouncing all over.

I checked connection into speedo, and connection at tranny, and all is well. I pulled out the cable looking for binds or frays, and there were none, however it was a bit on the dry side. I greased it up all nice and purdy like, put it back in, and apparently thats the cheapest mod you can make to a car, cause i was doing 90-100+ all the way home.

The ol' roadster sure is steady at those speeds.

In short...what the hell should i be looking for? Not exactly sure what is causing this. Is speedo bad?

speedo might just be bad : /
but that mod comment made me laugh a little

 

[sneakysnake]

It sounded like a dry cable until you said " At a dead stop, it said i was doing 20". Thats sound like you may have trash in speedo mech or just a bad guage.

 

[jmel]

It sounded like a dry cable until you said " At a dead stop, it said i was doing 20". Thats sound like you may have trash in speedo mech or just a bad guage.

With that being said...i did notice black marks on the cable....perhaps its rubbing against something? I dunno...has worked like a champ since July - just started this crap 2 days ago.

Naturally, it starts it RIGHT before i'm driving the car down to Austin for the Roundup.

 

[Sam_Fear]

Since the cable doesn't turn at a dead stop (unless your doing standing burn outs) it isn't the cable causing it to stick. It is in the speedo. The cable might have been causing additional grief, but greasing it should have solved that.