97 Dakota Differential Noise

97 Dakota with the 8.25 rear end. 189,650 miles.
The pinion seal went bad and all the gear lube sprayed out. I drove it about 10 miles before discovering the lube had gone. Hell of a howling
noise. Replaced the pinion seal and lube, but howling noise is still there. Noise is only apparent when under load. When I back off the gas, the noise disappears. What is the most likely problem? Pinion bearing, carrier bearings, wheel bearings, ring and pinion gear faces affected by heat are things I've thought of. I'm trying to decide if I want to take the time to fix this myself, send it to a shop, or just find a low mileage rear axle from a salvage yard and swap it in.
Any insight appreciated.
Ken Clarksville MI
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And all probable causes... you ran the bearings dry, and they've worn grooves into the races. Depending on how much heat was generated, the gears could have suffered damage as well.

If you're a competent DIY-er, have access to or can rent the following tools:
bearing splitter shop press (not exactly required - but would make things a little easier) dial indicator and adjustable base inch-pound torque wrench (beam or dial - click-type won't work) foot-pount torque wrench slide hammer with 2 or 3-jaw puller attachment Chrysler differential adjuster tool (can be made from simple components if you have a welder or someone who can)
You'll be replacing all bearings (carrier, pinion, and axle), and possibly ring/pinion gears as well, depending on how they look. If you can do it yourself, you'll be looking at about $300 in materials (or a little over $100 if the R&P are still salvagable), and probably close to a day's worth of work. If this is the route you decide to take, we can talk about specific steps and procedures.
A shop would probably charge you around $400-$500 in materials, and 4-6 hours labor. You can calculate that based on the going shop rates in your area.
If you can find a used axle with the correct gear ratio (only really critical if you have 4WD - otherwise, any gear ratio available in those axles that's acceptable to you will work) for a good price, it would save you a LOT of time (essentially, unbolt the old one, bolt in the new one, and bleed the brakes).
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<snip>

Thanks for the quick reply, Tom. I either have or can get the tools. What I'm not sure about is the time, plus what would be most cost effective. I'll check around for a used axle and see what the price and availability is first. If I decide to work on the old axle I'll surely take you up on your offer of more help.
Thanks again.
Ken
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Got an axle from a '98 w/ 36,000 miles on it for $350. Time is more of a concern right now than the extra money. I haven't done any differential work for about 25 years and I don't have the time to mess with it now.
Ken
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Even if I had the parts sitting on my shelf, I'd still choose to shell out the $350 for the axle, just for the convenience of it. By going this way, you're spending an extra $50 to $150, but saving at least 4 hours of time (if not longer).
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One potential problem. The new axle has 1 electrical hook-up at the differential, while the old one has 2. Will it still be usable?
Ken
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Two? Well, one's the wheel speed sensor - what's the other one? Can you describe the connector location, number of wires, etc. for both connectors on your old axle?
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My mistake. It was just a pigtail that made me think that there were 2. That, and the way the yard cut the wires on the new one.
One more question. What size torx do I need for the rear spring bolt? I'm guessing about a T-55.
Ken
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None...
Well, you could do that - but it's difficult. If you notice, the end of the bolt is hex-shaped, meaning you can put a wrench on the nut, and a smaller wrench/socket on the bolt itself.
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10mm on the end of the bolt worked well. Job is completed and the new rear axle assembly is working great.
Thanks for your advice, Tom.
Ken Olson Clarksville MI
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