As far as I can tell, the rear end is still the original for the truck (1999) with 148K miles on it. I've been trying to get help to determine what is making a scraping sound (the best description I can give is that it sounds like I have oversized tire sound on concrete, but ONLY when the gas pedal is pressed or at very low speed). I changed the differential gear oil and gasket this past weekend. The oil was at the proper level, but was very very old and needed to be changed. While in the differential, I looked at the gear teeth and they seemed to be fine (not rounded or broken). There were signs of dimpling on the inner part of the teeth, but otherwise were fine. A friend came over yesterday to help me with it. We did the test drive, and again, ruled out the transmission. He shook the driveshaft and said if felt good to him as well. He said the u-joints COULD be dry possibly. But his overall opinion was that the whole rear end needed to be replaced. The reasoning was that he didn't know precisely what was causing the sound, but it had to be in the rear end based on the test drive and what was NOT causing it, and it could be more expensive to start replacing parts than to just get another rear end. He's not a master mechanic, but he has owned 3 Dodge Rams and does all the service himself.

My question(s) for the forum are:
1) Would you agree? Is there a way to determine if individual parts of the rear end have failed? How?
2) should I take it to a mechanic? I hate doing this, but will do it if it's the best option.
3) if I have to replace the rear-end, where do I look and how do I know if it's got issues before buying it? what is a good price for a rear-end, and what all should be included?
4) what rear-ends will fit on a 99 1500 2wd (5.2L)? It has a 9 1/4 on it now.


Thanks for your time.

 

I just the the rear carrier replaced with an eaton due to the clips in the stock limited slip breaking out and casuing damage. at low speeds i heard what i believe is to be what oyu are describing. low speed and only with foot on the gas pedal. i replaced bearings, pinion and carrier bearings. all better. to test pinion bearing pull drive shaft off the spin pinion. most likely you can feel that it is not as smooth as it should be.

 

nothing you mentioned leads me to think you need an entire new rear end, just a reconditioning of yours.

 

Thanks. I don't understand the first line in your first reply. I don't know how to check all of that, but my Haynes manual should explain it. How do I know when bearings should be replaced?

 

First read this, http://www.fourwheeler.com/how-to/10...dana-trac-lok/

But around here you can get a 9.25 rear for $100 from the junkyard and it has a 30 day warranty, so if it is bad just get another one. Sure you're out the time swapping them, but with a friend you can have the whole thing done in under 2 hours.

 

U-joints can in fact make big ugly noises that will make you think your differential is dying. Were it mine, I'd pick up a couple of U-joints then get under there and remove and inspect the old ones. I'd replace them anyway just because U-joints are cheap and don't last forever, but my primary purpose would be the inspection of the old ones.

If the U-joints look good when opened up and the noise remains with the new ones, then it's time to start thinking about the rear end. For now, though, I recommend focusing your attention on the U-joints. They fail far more often than differentials do.

 

+1

9.25s are pretty stout rear ends.

 

Well, a couple of friends and I swapped out the rear end this weekend. Found a guy parting out the same make/model/yr as my truck with just over 100K on it, so I bought the rear-end from him. Then went to my friend's body shop and we swapped it out. Upon inspection, my u-joints were good. So were my shocks. But my original gears had a lot of slop, and you could easily see where the teeth of the spider gears were rounded off. We didn't dissect the carrier, but the new one was in much better shape. It took us about 3 hours to do it, but we were shooting the breeze and not in a huge hurry. Changed the gear oil. Used the new plug I had just purchased. I used my original drums and e-brake piston, but the shoes were about the same. Anyway, noise is gone. Truck rides well.

Is there any reason to keep the old rear-end? I'm keeping the extra lug nuts and brake springs. Is there anything else worth saving off the old one?

Now time to do the plenum gasket/pan swap, as well as timing chain, water pump, thermostat, transmission fluid change, coolant flush, etc.

 

You can sell it..... scrap it, or strip it, then scrap it. Or, if you have the space, and are a bit twisted... (like me...) you can stash it, in case you need anything off it later. If you just want it gone, take off EVERYTHING that will unbolt, put it in a box, scrap the rest.