Which Speedo Gear?

[Flip Smiley]

My speedo is of by 8 mph. When the speedo reads 50MPH my actual speed is 58MPH. I have a stock T5 from a '90 LX with yellow internal drive gear, 3:55 rearend gear, white 23 tooth driven gear, Auto Meter reverse read cable drive speedo, P275/50R15 tires.
Thanks, Phil

[Mustang Man]

http://tinyurl.com/5vkwpbg

:p

HTH...
Mark

[Mustang Man]

Here's the page from the FRPP catalog with the most common gear info. You most likely will not be able to get the right driven gear, as they don't make them higher than 21 teeth (Ford). The 23 tooth aftermarket ones don't always last. I would recommend changing the drive gear down to a 6-tooth from your stock 8-tooth, but that'll require R&R of the trans tailshaft housing.

http://www.fordracingparts.com/download/charts/129.pdf

HTH...
Mark

[Flip Smiley]

Thanks for the help.
Phil

[Lex]

I went from a 23T to a 21 and was still off by 5 mph. AutoMeter vintage reverse speedo. I found a 20T and it lasted 865 miles and the speedo jumped real bad than quit this weekend. Not for sure its the gear as the odometer quit about 50 miles before the speedo.

[gwnorth]

A good solution to this dilemma is the Speedhut GPS tach. Reasonably priced, easy to install, doesn't care which tire, transmission, rear axle ratio. And you can throw away the speedo cable before it melts and seizes.

[NC Jim]

I agree with gwnorth, after 1 1/2 years of trying to get it right and then figuring out the biggest probelm was the gear in the trans I threw in the towel. I just ordered the GPS speedometer from Speedhut and look forward to knowing how fast I am going.
Jim.