So I have an 89 Jimmy, had it for about month now and since I have owned it, at certain speeds I noticed a slight wah wah wah wah wah coming from the rear end, and a few weeks ago I was driving like 35mph and heard a pretty loud bang but the truck kept driving just fine and I didn't feel the bang, just heard it, but I wondered what it was, well now I know. I was planning on changing the rear diff fluid today anyway but when I parked my truck for about 7 hrs this morning after a 5 min drive during which I heard no odd noises, when I got back to the truck about 1 today there was a large puddle of oil under the rear axle and a hole in the cover... So I limped it home and it still drove fine except for the wah wah sound, pulled the cover and there are a bunch of teeth chipped off the ring gear. The oil that came out of the axle looked like grey metallic paint. So I'm going to try to get an axle from the junkyard but here is what I need to know.
As you all know the newer trucks list 3 digit codes on the glovebox sticker instead of listing the actual options, so I need to know where I can find these option codes decoded, so I can figure out the axle gear ratio. I am pretty sure it is a 3.42 as that seems to be the most common in these 80s and up trucks. It also has a posi, lsd if that makes a difference in what gearing it might have. Also, if I happen to run across a truck at the junkyard that is missing the option sticker, what is an easy way to tell the gear ratio. I want to be able to use my 4x4.
Last thing, am I thinking right to just replace the whole axle, I think this will be the cheapest route, junkyard axles are 90 bucks. But how hard is it and how expensive to replace the ring and pinion, or would other things need replacing as well? I have never messed with axles before so I am thinking I'll just get a junkyard unit.
As you all know the newer trucks list 3 digit codes on the glovebox sticker instead of listing the actual options, so I need to know where I can find these option codes decoded, so I can figure out the axle gear ratio. I am pretty sure it is a 3.42 as that seems to be the most common in these 80s and up trucks. It also has a posi, lsd if that makes a difference in what gearing it might have. Also, if I happen to run across a truck at the junkyard that is missing the option sticker, what is an easy way to tell the gear ratio. I want to be able to use my 4x4.
Last thing, am I thinking right to just replace the whole axle, I think this will be the cheapest route, junkyard axles are 90 bucks. But how hard is it and how expensive to replace the ring and pinion, or would other things need replacing as well? I have never messed with axles before so I am thinking I'll just get a junkyard unit.
If you put the time/money into rebuilding it you will have a guaranteed good axle, anything you pull used out of the junkyard is a gamble. Your call, there isn't necessarily a wrong answer here.
