Ok i have a 87 gxl... you can see it in my avatar, its got the stock wheels & tire size I'm trying to figure out what my speed is at about 2.5-3k RPMs in 3rd gear.
if anyone could give me an estimate that'd be great

Thanks,

87_gxl

 

my speedo broke too!

 

pick up a speedo replacement cable, if your speedo gear is still good you can feed a new cable through the housing.

 

i have a used s5 na speedo cable for sale. works great.

john

 

its an S4... I've just got S5 tails lol.... as long as the cable is no different from the one for an S4 I may be interested in buying it from you... to be exact with my issue it reads way over what speed i'm going, 60 mph its pegged at the M in mph, or 40mph reads 105-110mph, but its never the same

 

is it difficult to replace the speedo cable? would the dash need to be taken out? does this job take very long? I can't afford to be without my car for more than a day seeing as I have no alternative transport & I need to make it to work and home.

 

Go to http://www.f-body.org/gears/ and enter the info on your wheels, trans gears and Rear Ratio. it will give you approximate speed for each gear in 100 RPM increments.

 

Yes you have to remove the dash, no it isn't hard - 15 min job. It can come unclipped behind the dash very easily.

 

Ive got an extra cable that i could pull from an 88gxl. you can have the housing and cable...
pm me

 

If for some reason you do need to replace the cable, it only takes a few minutes to change. There is a seal inside the speedo drive gear. Chances are it has failed and feeding trans fluid up the cable and into the speedo head causing it to malfunction as you described. Hope this helps.