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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: BoobZ on April 10, 2008, 07:59:38 pm

Title: rear end question
Post by: BoobZ on April 10, 2008, 07:59:38 pm

ok so ive been doing the ole redneck rear gear check and i cant get it right..

since its an open diff. i only jacked ONE wheel off the ground to check this..

i can spin the Driveshaft 1 full rotation and i only get .75 turns out of the wheel.. 3/4s turns out of the tire..

I can spin the wheel 1 full rotation, and get about 1 and 1/3 rotation..

my question is, how come everywhere i look, i see people saying "you should be able to spin the driveshaft 2.73ish rotations before the tire completes a revolution"?

do i multiply the single wheel rotation trial by two making it 2 and 2/3 rotations? making it 2.73ish?

truck is an 86 2wd.. the code says it has a 2.73s in it..

Title: Re: rear end question
Post by: VileZambonie on April 10, 2008, 09:04:03 pm

I think you are in error. Put a witness mark on the driveshaft and a witness mark on the tire. Have an assistant rotate the tire while you observe the driveshaft.

You should rotate the tire 1 complete revolution

Title: Re: rear end question
Post by: BoobZ on April 10, 2008, 09:12:29 pm

been there tried that.. the driveshaft turns 1 1/3. 

my only guess is that you multiply 1 1/3 x 2 because of the open differential..

maybe if i turn both wheels forward at the same time?

Title: Re: rear end question
Post by: VileZambonie on April 10, 2008, 09:16:23 pm

Yeah you need to turn the carrier not the differential.

Title: Re: rear end question
Post by: BoobZ on April 10, 2008, 09:18:14 pm

ahhh.. that makes sense then.. lol  ill try tomorrow and see what i come up with.. thanks :)