Grinding Noise!!

[olddman]

I have a 489 8 3/4 differential with I believe Borg Warner Spin Resistant that needs to be rebuilt. Is this something that I could do or is it best to let someone who rebuilds rearends do it. It has been 50+ years since I have messed with a differential and just not sure about tackling this. Any idea what cost to have it rebuilt might be?

 

[Oldmanmopar]

Do you have the tools and Gauges to do the job. That would answer you question.

 

[Dartvader440gt]

Just because of time I have trusted friends that redo them for me. My buddy just went through my 8 3/4 from my 69 Dart. I'm sure I am more than capable but I work full time and have properties to care for. I pulled it, gave it a good powerwash and dropped it off to him. I cleaned all the leafs and hardware and I'll put it back in after I clean the underside of the car.

 

[Murray]

Unless you have the special tools for a 8 3/4", you can't rebuild it.

 

[olddman]

Do not have the tools to rebuild. However, I did pull the pumpkin and when I broke it loose from the rear end housing not much oil came out. That made me think that the bearings were shot. The manager of an O'Reilly's, who is a MOPAR owner recommended that I stop by and talk to the guy who builds/repairs transmissions for her race cars. Maybe he knew someone who could check it out. Stopped by and Tim said that he hadn't worked on rear ends for a few years but if I brought the differential by, he would look at it and give me his opinion. Took it to him and explained the noise that it was making and that after the axles were pulled there was no noise, it spun freely with no roughness. He looked it over and said the pinion bearing was a bit loose, but not enough to worry about. Said that the wear pattern on the ring gear look good, all the bearing were smooth with no noise or rough spots. Said that it could be that since the rear end was low on oil that the noise could be coming from the anti-spin unit. He said that he could pull it down and check everything out but said that I might try putting it back in, filling it up with oil and adding anti-slip additive. Drive for a bit and see if would free up the anti-spin. If not bring car by and he would listen for noise. He mentioned that it could be the transmission tail shaft bearing was bad and sound was traveling down drive shaft to rear end. Said that it wasn't common but to check bearing for roughness.

Checked tail shaft bearing and not rough so eliminated that. Plan on putting back together and see what happens.

 

[66fyssh]

I would do the same after he said it seemed OK. See what happens, it may just have been low on fluid.

 

[Murray]

Axle bearings commonly go out.

 

[olddman]

Had axle bearings replaced two years ago and haven't put that many miles on car. Won't be able to put rear end together until next week. Will post out come!

 

[TrailBeast]

Axle bearings commonly go out.

Had axle bearings replaced two years ago and haven't put that many miles on car. Won't be able to put rear end together until next week. Will post out come!

Pulled the axles and it was quiet and smooth?
Um, two years ago or not it points to axle bearings.
It sure is easy to check em while they’re out.

 

[oldkimmer]

If the pinion bearings are loose they need to be replaced. No if ands or buts. Kim

 

[olddman]

Started this project almost three months ago and was finally able to get the rear end back together again. While the rear end was out, I decided to replace all the lug nuts and washers. Tried to order some off the net but could not find any that would fit small bolt pattern Cragar S/S wheels. Went to several places here in Houston, but no one had them. The last wheel shop I went to suggested I go to Discount Tire. So, after weeks of searching the net and going from parts house to parts house I wound up going to the Discount Tire about three miles from my home and ordered the lug nuts I needed.

After installing the rear end, I then had a problem with the new Cragar washers that came with the new lug nuts. Several of the lug nuts did not want to torque down to 60 ft lbs. Instead, the lug nuts continued to turn and eat into the washers. Contacted Cragar and worked with Robert to get problem resolved. Manufacturer was contacted about any reported problems with the washers, and none had been received. I was asked to send the washers to Cragar so they could try to find what was wrong. Robert sent replacement lug nuts and washers for all of the ones I had purchased through Discount Tire. Installed the replacement washers and lug nuts without any issues. Have not heard back from Cragar yet about what they found problem was.
So now after months of problems everything is back together again, and a test drive was done Friday. Pleased to say that there is no noise! Do not know what caused the noise, perhaps the diff just needed to be cleaned and some fresh oil. Just don't know, but for now all is good.