I have a '97 Jimmy 4x4 2-door that was a bit of a basket case when I bought it. I put in a new engine and trans and just got it fired up tonight but haven't got it off the jackstands yet.

Much to my surprise, when I pulled the rear drums after seeing the rear brake lines were cut and blocked at the T, there were NO brake internal parts... and the ends of the axle shafts had yellow writing on them indicating a junkyard sourced part.

Given I have no history with this truck, I'm inclined to think that since there's no brakes, the entire rear end was likely swapped out.

How do I know if this is the correct gear ration for the truck... and if I try to engage 4x4 for the first time to see if it works... what problems might it cause if it's a mismatched rear end?

Sorry if this is a rookie question, but this is the first four wheel drive truck I've ever owned. Any help is appreciated.

 

when you have it on the ground and in 4wd your truck will not want to roll if you have different gearing. your front will want to turn at a different speed then the rear.


you can pull the cover off the back and it should say somewhere on the gearset, 3.42's are the most common. in your glove box the rpo code will tell you your factory ratio (don't remember 3.42, it u*7 *being wild cause i don't remember) GT4 is 3.73's and very rarely gt5 4.11's...

 

ive had a few trucks like this. you can put it in 4x4 and just go really slow. if the truck starts to feel like its breaking then the ratios are different. hopefully since he bought a junkyard axles he at least tried to match it up

 

You might be lucky enough to still have the Metal tag on it, but I doubt it. Just take the cover off and count the teeth on your Ring and Pinion gears. Then divide the larger number with the smaller.