i know i've seen this post before so i know there are guru's out there that know how to figure out what the gear ratio is on a rear end without taking it apart. i wrote it down a coupla years ago and put it in a place where i could always find it. LOL. if anyone would like to part with this bit of knowledge again i would surly appreciate it.

 

Flyn, I have read about jacking up one wheel, or both wheels, dividing by 7 and multplying by 12. I'm cornfuzzed.

One sure way is to have a bud with you and on very level ground, hand roll the truck one tire revolution and count the driveshaft revolutions. Some folk like to take a string to the ds and help with the count.

This method is the way it works in real time, and garneteed to work everytime, on both open and LS rears.

John

 

jacking the truck up and turning the wheel would be safer same effect

 

How is that Bob???

John

 

had friend do that on slipped and rolled the truck over his hand broke it also quick way to see if it opened or limited slip was added

 

You can jack up the truck, turn the tire one full revolution, and count the number of rotation the driveshaft makes, and that should be your gear ratio, like previously stated.

But if your lucky, there should still be a metal tag on the bolts on the differental center, and is should be somthing like
3 50 4M3803HJ
Or somthing like that which means 3.50 gears made in blank on blank date.

 

Check the Read First: FAQ thread at the top of the 73-9 forum for a real good method to find the gear ratio info.