hey all,

well my car had a 85 mph speedo in it, and it was off pretty bad because i went 2.73 to 3.73 for gears...well i changed to a 145 speedo and its off also which i know is right because of the gears...but now its off probably about 70 mph! going down the highway it says 145...my question is did the guy that i bought the speedo from just bolt a 145 plate to a 85 set of gears?? Or is it possible that the speedo is actually that far off?

thanks for any help guys!

 

I don't really see anything that could cause that kind of malfunction unless it is an electronic speedo. The only thing that should be causing the speedo to be off is the driven gear on the transmission. It needs to be changed to the one with the correct teeth for the new gears.

Other than that, I would say check the speedometer cable for any problems. I suppose that the speedo could be broken, but I have never seen one go before so I wouldn't bet on that being the problem.

 

+1

Your speedo is off due to the gear change, you can change speedos as often as you want, but until the drive/driven gear combo in the transmission tailshaft is corrected it will be off.

do a for speedo gear changes..there are several threads regarding this and I believe a tech article or 2. The correct gears are available from many aftermarket trans vendors.

 

Change gearing and, unless you swap out the drive and/or driven gears, the speedo will be off regardless of the speedo head: 85, 110, or 140. Check the following site:

http://www.transmissioncenter.net/sp...n_______va.htm

JamesC

 

alright thanks guys!!! i just wanted to make sure that the guy i bought it from didnt mess with me

 

Best way to calibrate the speedo is bring it into a shop where they can set it up on a bench and make the adjustments.

My "electronic" speedo and tach are adjusted by gently removing and repositioning the needles by hand.

 

Under normal circumstance, there is no need to calibrate the speedo head after a swap.

JamesC

 

The trick is not to touch the needles while handling the cluster. On the 90-92 models its much easier to maneuver the cluster with the clear cover off - so avoiding the needles requires constant attention.

 

well right now my speedo sits at like 8 mph without the car moving?