Just took my 87 Toyota 5 speed manual transmission and put 29 inch tires on it. The previous tires where about 26" diameter. Question> How do I get the speedo to read right? thanks.
- posted
18 years ago
Correcting speedometer
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- posted
18 years ago
You should be ok with what you have. What does the door sticker list as the tire size? Mine listed 225's. I had an '87 that came with 33's the previous owner had installed on it. Way too much tire for me. Before I put 235's on it I used this calculator
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to find theodometer/speedometer correction. When I put the 235's on it they wereright on according to the mileage markers and construction radar signs.
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- posted
18 years ago
There are speedo calibration calculators on the 'net that will help you.
The easiest thing should be to go to an offroad shop (or a speed shop, in a pinch) and see if they can help. Basically, the speed sender lives in the transmission (transfer case if a 4WD) and picks up from the Output Shaft. There is a small plastic gear that changes in size for the various tire and gear set combinations.
Don't forget, since you made the tires much bigger, then you will alter the performance curve on your truck. It won't have the same pick-up that it had, and it won't perform as well on hills as it used to. This is a function of the gear set in the differential(s). If yo have 4WD, then you have to change the gear sets in both diffs, if you only have 2WD, then you only need to change one gear set.