Please use jackstands!!!!!!!!
graham
graham
speed gauge not accurate
- Thread starter SlyMart
- Start date
- Thread starter
- #22
I haven't jacked the car but I have installled an speedometer app on my blackberry and went for a drive today and the cluster is exactly 10 km/h behind..
SM
exactly 10 km/h behind..
At what speed? 20km/h. Or 150km/h.. ??
Graham
exactly 10 km/h behind..
At what speed? 20km/h. Or 150km/h.. ??
Graham
- Thread starter
- #24
When my speedometer gauge is at 90 km /h then my speed on my app displays 80km /h when my speedometer is at 60 km /h my actual speed is 50 km /h. So something has to do with the rear end..
Driven gear needs to go up by about 2 teeth.
what diameter are the rear tires ?
- Thread starter
- #27
They are the factory 255's 60 15 on them.. I haven't checked the rear end on it yet but I am sure they are 3:70 gears
XFIRE82
Power User
did you ever get the speedo to show correct ? GM also used in the 70's and 80's a little gear box that went between the speedo cable and the tranny which could vary plus or minus about as much as 10 % . I used them many times to correct inaccurate speedo readings. This gear box plus changing the driven gear can give you many options to getting the needle to show correctly. Your diff ratio didn't change that much so I think just the driven gear might do the trick withoput having to go inside the tranny tail and change the drive gear to boot. 22 to 20 tooth is approx 10% so if your needle showed 100kmp with the 22, then it should be about 110 with the 20., etc etc.
Oh you guys are revving and buring gas !! , my 82 has a 2.87 ratio with the 700 o/d, 130kmp is only 2000 rpm. !!!!
Oh you guys are revving and buring gas !! , my 82 has a 2.87 ratio with the 700 o/d, 130kmp is only 2000 rpm. !!!!