My latest project GS has a 12 bolt rear end in it. The differential cover has the raised "eyebrow" on it. It takes roughly 3 and 1/4 turns of the driveshaft to make the wheel go around once. It is an open diff. What ratio do I likely have and what do you think it may have come out of? I can't see the numbers on it yet, too much crude. No tag on it. Thanks for your educated guesses.
while you were turning your tire, ...if the other tire turned forward or backward at all, your driveshaft revolutions wont mean much. the best way for a non-posi unit to check with no special tools or popping the cover off to read the numbers is .... park the car on a flat surface. chock the front tires. put the car in nuetral. jack one rear tire off of the ground. place a jack stand under the car for safety. count the driveshaft revolutions as you turn the tire exactly TWICE. if you get just uner 3 1/4, the ratio will be 3.23-ish, a little over 3 1/4 will be a 3.31, a little over 3 will be a 3.08, a little under 3 will be 2.93, a little under 3 3/4 will be a 2.73 ... etc. etc. here is why you have to turn the tire twice ... with the other tire on the ground as you turn the tire thats in the air ... the spider gears in the rearend cut the driveshaft revs exactly in half. its like ... did you know that when you peel out with a car that only has one tire spinning that the spinning tire is turning TWICE as fast as the speedometer says (minus what little speed the other tire actually might be rolling). so if you are at a dead stop and you punch it and the speedo jumps to 60 mph and you havent started moving yet ... that tire is spinning 120mph .... no wonder it cant get any traction in those situations.
Thanks Yuk, I did everything you said except I only turned it once. I actually turned the driveshaft until the the wheel made one revolution. Funny watching a fat guy go under the car, turn the shaft once, crawl out look at tire, crawl back under turn it again, crawl back out, etc. I will do it again by turning the tire twice. Thanks again.
scribe a mark on the driveshaft to keep track of the rotations. you can chalk a mark on the inside sidewall of the tire to keep track of it also.
