69 Chevy C20 rear end ratio?

[treveiger]

I have a c20 with a HO52 rear end if I'm not mistaken(compairing pics of them on here) and I went to figure out what gears are in the rear end. I did what I was told to do, jack up one tire, put the truck in neutral, an count the tire rotation and drive shaft rotation. For 10 tire spins the drive shaft spins 20.4 times. I did this with both tires an both got the same out come. I thought these rear ends came with 4.10 or 4.58 so how is possible? Did they make a aftermarket gear for these rear end? Any info would be great!
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[yuccales]

I thought spin the tire one revolution, count how many times the driveshaft turns.

[JimKshortstep4x4]

If you only spin one tire then you have to multiply the number of driveshift spins by 2 as the drive shaft spins 1/2 revolution for each spin when only one wheel is turned.

So in your case you would multiply 20.4 x 2 = 40.8 then divide by 10 you end up with 4.08 which is very close to 4.10. Did you check to see if the tag is still bolted on with the one of the cover bolts?

Jim

[bollybib]

There should be a two letter code stamped on top of the carrier that identifies the gear ratio. Mine was JU (4.10). I also counted revolutions to confirm and got a number very close to 4.10.

Here is a pic of mine for reference:
http://67-72chevytrucks.com/vboard/s...8&postcount=39

[treveiger]

Originally Posted by JimKshortstep4x4

If you only spin one tire then you have to multiply the number of driveshift spins by 2 as the drive shaft spins 1/2 revolution for each spin when only one wheel is turned.

So in your case you would multiply 20.4 x 2 = 40.8 then divide by 10 you end up with 4.08 which is very close to 4.10. Did you check to see if the tag is still bolted on with the one of the cover bolts?
Jim

That makes sense! Thanks a lot I couldn't figure out how to do it and it was making me mad.

Originally Posted by yuccales

I thought spin the tire one revolution, count how many times the driveshaft turns.

I did that too but came out around the same.

Originally Posted by bollybib

There should be a two letter code stamped on top of the carrier that identifies the gear ratio. Mine was JU (4.10). I also counted revolutions to confirm and got a number very close to 4.10.

Here is a pic of mine for reference:
http://67-72chevytrucks.com/vboard/s...8&postcount=39

O ya I'm subscribed to your build thread! You go into so much detail I've learned a lot.
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