Got the new speedometer cable installed today. Now here is the problem. it shows I am going 35mph when I am only going 25. I know the rearend gears are 3.73, not the factory 3.23. This is in a 83 T/A. Do I need a different transmission drive gear to get it into proper range and where do I get one?

suks2bu37

 

Welcome to TGO. Listing your car, make, model, motor and trans is always helpful. For example, you don't mention if you have the 700R4 (auto) or the T-5 (manual).

Yes, you'll need to change the driven gear. Check the stickies in the Transmission and Drive Train section for the proper gear.

You'll be able to purchase what you need from the following company:

http://www.transmissioncenter.net/sp...n_______va.htm

JamesC

 

Sorry,
The car is a 1983 T/A Daytona 500, the transmission is a 700R4. Motor is the crossfire injected 305. I will check the stickies and see what they have to say for me being an idiot.
suks2bu37

 

You need the 15 tooth drive gear. Driven gear depends on your tire size.

 

Drive gears, you must remove the tail shaft housing, which means pulling the drive shaft, and some fluid might leak out.

Driven gears can be changed with out pulling the tail shaft housing, unless it stuck in there good like it is most times and ya end up pulling the tail shaft housing to knock out it anyways

Car angle will depend on the amount of fluid leakage.
Jack up all 4, for less loss/mess.

Its fun, never got mine 100% cause of my odd combo.
But I’m cool with it being 5 under. At 60 its 55.9, so natural instinct to run 5 or more over, keeps me in the safer zone when putting around town.

 

that's true, but the speedometer WILL NOT calibrate with a 17-tooth drive and 3.73:1 gears. Let alone 18 tooth or 19 tooth.