Gunstar1
04-08-2006, 09:48 PM
Some friends of mine and I did a axle swap in my 77 Firebird. Now the speedometer is WAY off. I can drive 90 (according to the speedo) and everybody is passing me.
The car used to be:
TH350 with 2.56:1 rear axle.
What the car is now:
TH400 with 3.42:1 rear axle (posi)
The speedo didn't seem far off with the change from the TH350 to the TH400, but the recent addition of the new axle it throwing it way off.
As I understand it, there are some speedo driver gear(s) that can be changed in the transmission to fix this problem.
Is this hard to do, or is it something that should be left up to a transmission service center?
The car used to be:
TH350 with 2.56:1 rear axle.
What the car is now:
TH400 with 3.42:1 rear axle (posi)
The speedo didn't seem far off with the change from the TH350 to the TH400, but the recent addition of the new axle it throwing it way off.
As I understand it, there are some speedo driver gear(s) that can be changed in the transmission to fix this problem.
Is this hard to do, or is it something that should be left up to a transmission service center?