AUBREY- that's what my thoughts were but how do I check if there the same
gear ratio or not?

 

To start, there should be tags on the diff. covers held on by the cover bolts.

 

AUBREY- ok if it is differnt gear ratios how would I check that?

 

Oh ok and if they aren't there what would be another method?

 

I'm assuming you don't have any info on what was put in the rear.

Put the rear on jack stands and the tranny in N. Rotate the rear tire and for one full revolution of the tire, count how many times the yoke rotates. This will only give you a rough idea but should be good enough. An example would be maybe one full rotation of the tire equals 4 1/5 rotations of the yoke. Put the truck back down and do the same thing on the (driver side) front.

If it is really close, you're probably ok. If it's like 4 1/2 on the rear and 3 1/2 on the front, do not put it in 4 until you get your ratios matching. You'll rip your drivetrain apart.

 

+1, I'm thinking since the front was not changed, the tag should be there atleast. Unless someone serviced it and didn't replace the tag.

 

Ok I will defiantly Check that now, so Since I'm gonna be down there should there be anything else to check for?

 

Right i know that i shift it in all the time(well in winter) at speed. But i have never shifted in to low range at speed. As you stayed you could do at 15mph?


Josh

Ps sorry for confusion.

 

the problem with both wheels in the air on an open diff, is that the spider gears are free to turn, and if that happens ANY, it gives you a wrong answer.

i think this is a better way to check... assuming you have an open differential.

jack up one tire. turn the tire until the drive shaft rotates to a point where the weight is pointing straight down, or make a mark on it. make a mark on the tire. turn the tire exactly 2 revolutions and count the revolutions of the drive shaft. its going to be a number like 3.5 or 3.72 or 3.91 or 4.10 or 4.56

if you have a limited slip differential that works, or a locking diff, then with one tire in the air and one on the ground, it may refuse to turn. if so, then jack up both tires, and turn them one revolution.

 

since you will have the wheel off the ground you may as well grab it at 12 and 6 and push/pull on it to check for movement (ball joints/hubs) and grab the axle shaft by the u joints and push/pull on it to feel for movement which would indicate that they are bad.