I went from an 85 to 110 with no problems. I recently swapped in a 145 (I used the VSS that came with the speedo) and now the needle will bounce from 65 to 80 miles an hour at 70. Suggestions?

JamesC

 

Check your speedometer cable for binding, if that's not it, you have a bad speedometer head.

 

Would some graphite spray such as Lock-Ease be beneficial on the cable?

JamesC

 

It might help.

 

I removed the 145 cluster, stuck the old VSS (I know, I know) back on, and shot some graphite lube in the cable. Now it's only bouncing, perhaps 5 mph, at 70. I don't know whether to try lubing one more time, since it helped, or simply stick the 110 speedo head back in.

JamesC

 

You could try to lube the entire length of the cable too.

My speedometer bounces a little and reads low right now becuase I really hate pulling the head out to get at the cable. :P

 

Is removing the cable as simple as pulling and twisting until it comes free? How about reinsertion?

JamesC

 

Just pull it straight out, it should come out without much fuss. If you want you can disconnect the cable housing at the transmission too and spray some brake cleaner down from the top to flush out any crud that's in there first. When you reinsert the cable, you might have to turn it a little to line the square end with the hole in the gear in the transmission. You might also need to turn the shaft on the speedometer a little to get it to seat fully when you install the head too.

 

Cool. I may put the 110 in again tomorrow to see what occurs. If it too suddenly has a problem, then surely the cable is at fault (though how swaping one speedo for another would cause difficulties is beyond me). If it functions as well as it always did, then the 145 has a problem. Because the 145 improved after the lubing, I'm intrigued at what the results might be.

JamesC

 

FYI.

I swapped the 110 back in this morning. It's right on the money, so the 145 speedo head must have a problem of some sort. I think I'll see what my GM parts man says about sending it for repair--may be cost prohibitive however.

JamesC

 

I've been quoted something like $300 Canadian before to repair thirdgen speedometers.

 

Ouch!!! Well, I'll pick up another somewhere sometime before I cough up that kind of dough. The parts man is supposed to be getting an idea of the cost this afternoon.

JamesC