Axle ratio?

[1$Chuck]

Is there an easy way to tell what axle ratio a 1st gen truck has? Is it stamped somewhere, or is there a way to decipher the VIN number?

[Richie O]

If the tag is still under the hood and its original then its listed there. There also may be a tag on the housing if its not rotted off. Over the years there were only 3 ratios available for the whole series. 89 through 93.

[meby]

Or call your dealer. They can tell you what the original one was based on the vin #.

[1$Chuck]

Thanks guys. After some wire brushing of old dirt and crap off the differential housing, I found the tag. 4.10 gears with manual transmission..no wonder it seams like I'm driving a tractor.

[flyinredneck]

where was it at on the housing

[PToombs]

Mine was stamped on the right axle tube just out from the center housing.
Rear side.

[DieselLam]

That works if you know your gears are stock. If they might not be then Jack rear end up turn,driveshaft one time while counting how many times your tires turn.

[Richie O]

That works if you know your gears are stock. If they might not be then Jack rear end up turn,driveshaft one time while counting how many times your tires turn.

Kinda. Its the other wy around. How many driveshaft turns to 1 tire revolution. You also need to make sure both wheels are up and that both wheels spin the same amount. ( make sure a brake is not dragging the wheel )

[DieselLam]

Oh yeah thats right , thanks

[flyinredneck]

so say the dr turns 4 times and your tires turn 11 you have 4:11 's

[Fred_M1010]

so say the dr turns 4 times and your tires turn 11 you have 4:11 's

No, it's 4.11:1 and not 4:11.
So 37 turn on the driveshaft gives 9 on the wheel (37/9=4.11)
Or you could just count the turns on the DS while turning the wheel 1 turn.
If it turns 4.11 times, you have 4.11 gears.

But as stated above both wheels must turn the same for this to work.
If you have a limited slip this is no problem, the other wheel will follow if you jack up both of them.

But if you have an open diff you can also do it by jacking up only one wheel.
Then you have to turn it 2 turns instead of 1, to get the proper count on driveshaft turns.

But why not open the diff cover and check the markings on the ring gear,
it's probably time to change the oil anyway