Rear End Noise 8 3/4

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harley97sp

harley97sp

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I have a 70 Dart Swinger with a 8 3/4 rear end. When I press on the gas pedal I can hear a whinning noise from the rear end... It stops when I let off the gas and starts again when gas is given.

I have been told I need to "set up" the rear end to stop this noise of whinning/whinding.

What is required to "set up" the rear?? Is it a complicated process? Special tools required? etc. etc.....

Any suggestions?

Thanks

Jeff
 
I have done it, but darned if I could explain it to you very well.

Yes, it is kind of complicated, pinion depth being the most difficult for me, since the bearing has to come off to facilitate adding or removing shims. If the pinion depth is not correct, you can not get a perfect pattern on the ring gear.
 
for setting it up, at a minimum, other than your normal mechanic tools, you will need a dial indicator, bearing separator (for pulling the bearing off the pinion) and a press to put it back on. You also need a spanner wrench (home made is fine) to turn the carrier bearing adjusters. Get a book that shows how to do it and shows the contact pattern you are looking for. Older Motors manuals(50s -60s) are great for that or you can probably find that info online somewhere as well.
 
You need to check the wear pattern on your gear set. To check this you will need marking compound. Chances are, if you are hearing noise only on acceleration, the pattern is off on the drive side of the ring gear.
Pretty much, you'll pull the third member from your rear, set it on your workbench, paint the compound on 3 or 4 ring gear teeth, then turn the drive pinion one full turn in each direction. The gears will mesh as you turn and there will be marks on the ring gear teeth where youur pinion contacts the ring gear.
You look at the location of the wear pattern to determine what needs to be adjusted, depth, preload, or backlash.
Then, depending on your rear, you would adjust with shims, spacers, or crush sleeves
 
Wow, you guys really know what your talking about. I think for my level of mechanic I better just take it to a shop that can do it. I appreciate all your guys help and I will copy and paste all the responses so he can see what your talking about.

Just a quick thought.......It sounds like this is what is causing the noise on acceleration is that correct. I know it is not the tranny or the drive train cause it has been balanced and the transmission has recently been rebuilt. Just making sure that this is what is causing the noise. Any input???

Thanks again guys you all have been very helpful.
 
For what the tools cost between the 2 tq wrenches, dial ind, press or clam shells .....

You can pay a pro to set it up and have no worries...
 
Rear end noise on acceleration=...improper gear mesh. Yes, take the center section out and take it to a qualified rearend person who knows Mopar rear ends. If it is a 742 or 741 case, it will be a shimmable pinion gear. If it is a 489 case, it will have a crush sleeve. If it is a 489, I would suggest that you get the new hard spacer to install in place of the crush sleeve, thereby making the pinion depth shimmable on the 489 also. Not a difficult procedure and should only cost about $50.00 to have properly setup, unless of course you need some replacement parts in there also. Good luck with the project, Geof
 
...........Hate to burst ur bubble, but 1ce gears start whining, there is little u can do to stop em................kim..........
 
oldkimmer said:
...........Hate to burst ur bubble, but 1ce gears start whining, there is little u can do to stop em................kim..........
Click to expand...

I disagree with this. Reason being is when I was a kid I installed a set of 410 gears in my Dad's 69 Charger, welded the spider gears for full posi etc. The Rear End made a Horrible whine, we drove it like that for a few months. Yes we POUNDED on that gear set even though it was whining like crazy and making ALL KINDS of noise.

I tore it apart and brought it to a rearend guy. He set it up properly and the whine was no more.
 
cosgig said:
Rear end noise on acceleration=...improper gear mesh. Yes, take the center section out and take it to a qualified rearend person who knows Mopar rear ends. If it is a 742 or 741 case, it will be a shimmable pinion gear. If it is a 489 case, it will have a crush sleeve. If it is a 489, I would suggest that you get the new hard spacer to install in place of the crush sleeve, thereby making the pinion depth shimmable on the 489 also. Not a difficult procedure and should only cost about $50.00 to have properly setup, unless of course you need some replacement parts in there also. Good luck with the project, Geof
Click to expand...

wow $50? I called some shops around my neighborhood and they want $250 at the minimum
 
If you live here in Michigan, bring it to my buddy Chris Sager in Hamburg. He'll do it for $50.00. Lets see...$250.00 divided by lets say $65.00 an hour for labor, thats a little over 4 hours. If you can't get a shimmable center section set up on the bench in under 4 hours, you should not be working on it IMO!!! Even setting up a 489 with the crush sleeve shouldn't take that much time. I would still say, take it to a qualified rearend person who knows MOPAR rearends. I took a center section to my trans guy (who also happens to know Mopar) and he fought it for 3 or 4 hours and finally told me..."Thats the best I can get it". Howled like a lone wolf. Took it to Chris, quiet as a mouse in about an hour. When you called around, did you tell them you would just be bringing in the center section. If they had to R&R the center section out of the rear then I could see $250.00 to remove it, set it up and replace and re-adjust it. Geof
 
I don't know....i do mopar rears, and quite a few super stockers you can see wheels up....

Im not going thru all that for no $50....

Even if i work at a somewhat fast pace.... setting the depth, then the pattern and then the preload.....then final assembly... that is without doing the ring... (you handing me a packed carrier and pinion gear)

Cleaning it thoroughly takes a damn good 15 minutes, or more... then set it in the jig to hold it in the vice...

I can't count how many 742's i have done and spent an hour getting the preload perfect.....or shaving a shim because they didn't come with what was needed.... Way less time setting up a crush collar then a shim...

Your guy is tq'ing these to spec with shims and getting it all done in under an hour...

Sounds to me if your boy is doing it under an hour he is just getting lucky...
________________________________________________

You can either get the gears quiet or much quieter if they're set up wrong...
 
Thanks guys, I have taken all of your advice and I made an appointment for next Wed at a garage that has all the mopar tools (or so he says) and diffenetly sounds like he knows what he is talking about. He says he would like the car for Wed and Thurs to ensure he does it right. My thought exactly lol.

I will let you all know how it works out with $$$.

Thanks so much

Jeff
 
I agree with the comments of "once noisey always noisey" and no way is quality work gonna happen for $50. Work at a 4wd shop for a little while. You eat and sleep gear swaps and repairs. The rule is if there is a whine and there's more than 50miles on them, expect worst case. I have the checking bearings and tools to do them. Case spreader too. And I wouldn't dream of saying an hour. That's enough time to run a pattern, carefully take it apart, and clean the stuff. Never mind fixing it.
 
If it just recently started whining it very well could be the inner pinion bearing going south. On acceleration the inner (large) pinion bearing is taking most of the load. Regardless if it's the ring & pinion or bearings it needs to be opened up.

I would also agree that a 4x4/truck repair place is your best bet for the repair if you don't have a differential only repair shop.


Chuck
 
Ive got the same problem
also the passanger side bearing is leaking tiny bit and coating the drum brakes.
we just had the 8 3/4 straightend.
 
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