ok awhile back i got a 145mph gauge cluster from a 87 iroc-z and when i put it in my 85 iroc-z all the gauges work except the spedometer,when i drive down the road it acts like its reading my speed but when i speed up it starts going "crazy",what i mean by that is the needle jumps up and down and it makes a wierd vibrating/grinding noise and im not sure why it does that,im pretty sure the from 85-89 the gauge clusters were the same with wiring and being cable driven,my 85 mph spedometer works fine so can someone shed some light on this annoying problem of mine thanks

 

You might try greasing the cable. Just the last 3/4 of it (closest to trans) with a thin coating of white lithium grease.

 

where does the spedo cable go into the tranny at,does it come on the driver side or passenger side,not to sound retarded but im still learning about cars and will plain old black grease work or do i have have special kind?

 

Remove the cluster from the dash and unscrew the cable from the driver's side of the tranny. Remove the cable from the cable housing. Shoot the housing with brake clean until the fluid runs clear. Shoot the cable itself. Reattach the housing at the tranny end. No black grease. Purchase some Sil-Glyde from Napa (lube for speedo cables and other things). Squirt a glob in the palm of your hand and run the cable through it as you thread the cable back into the housing. You may have to twist the cable a bit to reseat it in the driven gear. Button up. All should be well unless, of course, the speedo head is shot. If the trip odometer doesn't function, check the following link:

https://www.thirdgen.org/forums/faq-...-fix-pics.html

JamesC

 

if those dont work oyu could just pick up a new cable, they are like 15-20$ if i remember correctly

 

but see what i dont understand is why does my factory gauge cluster work fine including the spedometer but the 145mph spedometer doesnt work right

 

Have you put the 85 back in? If you have and it still functions as designed, the 145 head is probably defective (and it may be anyway).

JamesC

 

yea i put the old cluster back in and it seems to work as it dosnt jump around or make that weird noise,the 87 iroc i got the cluster out of was wrecked in the front