Speedo reads High

Ok, it's been awhile since I have been on, This is aproblem with my last project car, a 1999 CVPI where I replaced the engine and trans with the drive train out of a 1996. Everything is fine except for the speedo, At 60 I am guessing it reads about 72, I did change the speedo gear in the tailshaft with the one from the 99 trans, the 99 has 3.55 gears and the 96 had 3.23, any other ideas on how to calibrate it short of a reprogram of the PCM, which I will not do, I'll live with it.

OK, nobody has any idea's ? Does anybody know if there are multiple versions of the speedo gear in the trans availible? Some thing I was wondering, the car the trans came out of has p225-7015 tires and the 99 has p225-60-16 tires. Also I ran through a side of the road speed device an determined my speedo is of by 20%

Did you try using the speed sensor out of the 99? The pulse rate of the 96 speed sensor might not agree with your 99 speedo. If that does not work you, you may want to consider an electronic ratio adapter


OK, nobody has any idea's ? Does anybody know if there are multiple versions of the speedo gear in the trans availible? Some thing I was wondering, the car the trans came out of has p225-7015 tires and the 99 has p225-60-16 tires. Also I ran through a side of the road speed device an determined my speedo is of by 20%

Ok, it's been awhile since I have been on, This is aproblem with my last project car, a 1999 CVPI where I replaced the engine and trans with the drive train out of a 1996. Everything is fine except for the speedo, At 60 I am guessing it reads about 72, I did change the speedo gear in the tailshaft with the one from the 99 trans, the 99 has 3.55 gears and the 96 had 3.23, any other ideas on how to calibrate it short of a reprogram of the PCM, which I will not do, I'll live with it.

That is a big problem when switching transmissions.
Some have different gears set up inside on talil shaft.
But if speedo is reading fast look for a gear with more teeth to help slow it down.
MT