speedometer tranny gear

[tpodwdog]

ok,,,,heres the dillio. my speedo was reading 10 mph slower than my GPS....I.E...... if the GPS said i was going 50 mph....the speedo said i was going 40 mph...SOOOOOOOOO..... i asked you guys how to fix this and yall said " new speedo pinion gear with 36 teeth, the RED one. well...i just replaced the speedo gear. there was a 39 tooth GREEN one in there and i put in the RED 36 tooth gear. its still; reading the exact same. WHY is the question.

3:55 rear end gears and the back tires are 27 inches in diameter...the chart was calling for a 36 tooth RED gear.

the green gear was a bigger circumference than the red gear so this should speed up my speedo,,,,RIGHT??? what am i missing here????

( yes i know its a 3:55...i checked.....wheel back turns once and the driveshaft turns 3 and 1/2 times = 3:55)
(yes also...the indicator is at 6 o'clock with the proper numbers at the bottom)

IM BAFFLED!

 

[1badstroker]

According to the information I have the gear should be a 34 tooth for a 3.55 gear and 27 inch tall tires. The 36 tooth gear works with a 27 inch tire and a 3.73 gear. Good luck, I have to fix mine one day also, no time. I am 10 to fast.

 

[tpodwdog]

According to the information I have the gear should be a 34 tooth for a 3.55 gear and 27 inch tall tires. The 36 tooth gear works with a 27 inch tire and a 3.73 gear. Good luck, I have to fix mine one day also, no time. I am 10 to fast.

ok...hurry up and take yours out and mail it to me and ill do the same....then both of our speedos will be ON !:headbang:

 

[hunt2elk]

I haven't had very good luck going by the charts, but having to use trial and error. I have found that every 1 tooth change will change the results about 2 mph in the 50 to 60 mph speed range. As far as your 36 and 39 tooth gears giving the same result, this isn't possible unless the tire size or gear ratio have also been changed. Some of the aftermarket gears have numbers on them that don't corrospond to the number of teeth. Did you count them by any chance?

 

[tpodwdog]

I haven't had very good luck going by the charts, but having to use trial and error. I have found that every 1 tooth change will change the results about 2 mph in the 50 to 60 mph speed range. As far as your 36 and 39 tooth gears giving the same result, this isn't possible unless the tire size or gear ratio have also been changed. Some of the aftermarket gears have numbers on them that don't corrospond to the number of teeth. Did you count them by any chance?

nope....nuthin changed but the speedo trans gear...im as baffled as you are and yeah i counted 'em !