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This is a bunch of speedo gears I purchased at the Louisville, KY swap meet today and I thought it might be useful for those of you who have speedometer error caused by switching to a different size tire diameter or different rear axle ratio. This is the part needed to fix that.
The two pale green colored gears on the right are for a Four Speed transmission. Notice the teeth slant the opposite direction of the ones on the left which are for automatic transmission such as C4 and C6.
The five gears on the left are:
21 tooth (red),
20 tooth (black)
17 tooth (white)
16 tooth (maroon)
The stock application chart uses tire sizes which are useful as a reference but since they are all bias ply 14 inch tires they are not a whole lot of help unless you have reproduction bias ply tires.
To illustrate what works, I have 3.50 gears and 215/70R-14 tires on my green GTE and the speedo is accurate. It has the black 20 tooth gear installed.
I have 2.75 gears in the blue GTE with 215/70R14 tires in the blue GTE and the speedo is accurate with an 18 tooth gear.
The two pale green colored gears on the right are for a Four Speed transmission. Notice the teeth slant the opposite direction of the ones on the left which are for automatic transmission such as C4 and C6.
The five gears on the left are:
21 tooth (red),
20 tooth (black)
17 tooth (white)
16 tooth (maroon)
The stock application chart uses tire sizes which are useful as a reference but since they are all bias ply 14 inch tires they are not a whole lot of help unless you have reproduction bias ply tires.
To illustrate what works, I have 3.50 gears and 215/70R-14 tires on my green GTE and the speedo is accurate. It has the black 20 tooth gear installed.
I have 2.75 gears in the blue GTE with 215/70R14 tires in the blue GTE and the speedo is accurate with an 18 tooth gear.
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