Gear ratio
 

Someone on craigslist has a rear end for sale. How do I tell what the gear ratio is if there is no markings? How many turns of the axle compared to the shaft input? I am looking for 3.73's.


Gary

Re: Gear ratio
 

Approx 3 3/4 turns of the pinion to one turn of the axle.

Re: Gear ratio
 

What is it with the 3.08's for comparison? That is the 4 speed truck gear ratio right?(3.08).

Re: Gear ratio
 

buying a 40 year old rear end i'd want to look at the gears to see condition// the numbers are stamped on the gears

Re: Gear ratio
 

Just a smidge over 3 turns on the pinion for a 3.08 to 1 turn of the axle. The number represents a ratio of turns of the pinion to axle, like 3.73 to 1, or 3.73:1. 4.11 would be 4.11 turns per 1 turn of the axle.

cdowns has a valid point.

Re: Gear ratio
 

I agree with CDOWNS, I would ask to remove the cover, and look for numbers on the ring gear. It SHOULD say something like 41-11, which would be a 411. If you see no numbers which I doubt, just count the teeth on the ring and pinion, bring a calculator, and divide the pinion by the ring gear and do the math. The other upside to pulling the cover is to look to see what the gears look like /// rusty, broken teeth, etc

Re: Gear ratio
 

I agree with cparman and cdowns remove that cover and see what you got inside. Also if I remember this right the numbers on the gears are 40 13 is a 307 and 41 11 is a 373. Or divide the big number by the little one and there you go.

Re: Gear ratio
 

I agree with the others, if I am going to buy I like to look first