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what rearend gear ratio do i have?

669 views 4 replies 3 participants last post by  Doubleclutch 
#1 ·
i spun the driveline 16.3 times, and one of the rear wheels went around 10 times.
 
#2 ·
Rear Ratio?

I think the computation is 10/2 equals 5 turns on both the rear tires. Then 16.3 divided by 5 is 3.26. Plus/minus tire size and overdrive kick up if equiped.

Lots of RPM to speed calculators on the web. run a goggle on RPM Speed if you have a tack to recheck. You also need tire size.
 
#5 ·
Your Close If the Other Wheel didn't Turn.

You can tie it in tighter with a degree wheel and a wire marker threaded through the U-Joint. If its a GM 3.23 and 3.42 were popular. The opposite rear can't turn. Or pull the back plate on the differential and count the teeth.

I just changed out mine. I had it worked out using tach and speedo and the online calculators at 2.94 or 2.73. It turned out to be 2.42! Lots of difference going to a 3.42. If your looking at change, run some numbers and listen to your engine. I don't like going above 3.5 if your doing much highway driving. I was at 2,200RPM at 70, now around 3,000RPM. But lots more pep!
 
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