Axle Retainer Nut Torque w/ Green Bearings?

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stop the beast

stop the beast

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I installed an 8 3/4 recenty and I've finally got the car on the road with a 3.91 clutch type suregrip which was professionally inspected and I'm told it looked really clean and totally functional. The suregrip is working great going straight and on turns. The issue is that I'm getting a slight "whinning" or "whirring" noise when I'm at lower throttle and the wheels and axle housing are very hot to the touch after a drive. Not hot enough to burn a bare hand but hot enough to be uncomfortable.

I'm trying to troubleshoot the issues and I'm wondering if the axle retainer nuts could be overtorqued, my manual says 35 ft/lb stock but I'm sure I put them on to more like 50 ft/lb and that numbers for stock bearings anyhow. I need to pick up a torque wrench and verify. Does anyone know if 35 ft/lb is okay with sealed green bearings?

Oh, and the gear oil should be full. I will verify as well but put 2 qts and it was right at the fill hole when level.
 
Bolt torque is not the problem. I'm not familiar with the "ins and outs" of green bearings but I've heard some talk of pulling out the middle thrust button. Could that be an issue?

Hot? could be bearings, or brakes? How hot is it there? How long/ fast do you drive, and how much and how hard do you use the brakes?
 
It sounds like the noise and the heat are unrelated. Seems like a typical amount of heat from what you describe. If it is more of a gear howl instead of a bearing growl, then I would suspect the pinion gear depth is not quite set correctly. If it is not too terribly bad, I wouldn't worry with it. You can always remove the center section and inspect the gear pattern if it is a big concern. The pinion gear contact patch on the drive side of the ring gear teeth should be in the center of the ring gear teeth. Ring gear backlash should be about .008".
 
You did grease the bearings, right? They don't get lubed from the gear oil. Also if you are running greens the thrust buttons need to be removed from the suregrip.
 
The green bearings are sealed but you do need to remove the
thrust button as was stated in the previous post. I had the
same issue.
 
The thrust button issue is sort of coupled with the axles he's using. I emailed Dr. Diff about it when I put green bearings on my new rear end and he said if you are using the stock axles it doesn't matter, you can leave the button in or take it out. Aftermarket axles tend to be a little longer so they have more of the splines engaged in the rear end and be more likely to hit the button. I left the button in mine so far and don't seem to have any issues aside from a whine that I'm fairly sure is gear setup related. I should have checked it before I swapped the rear end in, but I was impatient.
 
....if there factory gears more than likely they have 2 much backlash.........but they will still whine anyways......kim,.
 
Thanks for all the feedback. I'll have the gear backlash checked eventually, my 3.91s are stock. Are aftermarket gears quieter than stock? As far as the "whine" goes?
 
Map63Vette said:
The thrust button issue is sort of coupled with the axles he's using. I emailed Dr. Diff about it when I put green bearings on my new rear end and he said if you are using the stock axles it doesn't matter, you can leave the button in or take it out. Aftermarket axles tend to be a little longer so they have more of the splines engaged in the rear end and be more likely to hit the button. I left the button in mine so far and don't seem to have any issues aside from a whine that I'm fairly sure is gear setup related. I should have checked it before I swapped the rear end in, but I was impatient.
Click to expand...

I was able to leave the thrust button in mine also. I installed one axle and then took a tape measure and stuck it in untill it came in contact with the button and I had more than the axle length. So I installed the other axle.
 
I would pull that third member and check the pattern snap some shots and will have a look see. It could be starting to finally break down to the edge of the gears meshing and will resonate a whine noise when coming off each other.

Bearings also can be checked with a tug in and out up and down and double check the backlash NO tighter than .005 no wider than .010 .

Good luck and hope to see some pictures.

IF you want to run a pattern and do not have marking compound you can use a girl friends or wives old bright lipstick or clown make-up some sort of grease colored paste.

Jim
J D Race
 
I have heard that Richmond Gear ring and pinion set up even when installed correctly may have a little noise.
 
monzaz said:
I would pull that third member and check the pattern snap some shots and will have a look see. It could be starting to finally break down to the edge of the gears meshing and will resonate a whine noise when coming off each other.

Bearings also can be checked with a tug in and out up and down and double check the backlash NO tighter than .005 no wider than .010 .

Good luck and hope to see some pictures.

IF you want to run a pattern and do not have marking compound you can use a girl friends or wives old bright lipstick or clown make-up some sort of grease colored paste.

Jim
J D Race
Click to expand...

good info........ and welcome to FABO!
 
It'll be a few weeks at least but ill get the chunk out and check the gear pattern. Should I just sludge the compound on the pinion and spin the gear a few times?
 
stop the beast said:
It'll be a few weeks at least but ill get the chunk out and check the gear pattern. Should I just sludge the compound on the pinion and spin the gear a few times?
Click to expand...


You do not want a TON of it just paint it on to just get a nice even light coat so you can not see the dark or shiny color of the tooth do about 6-7 teeth both sides and when you do spin it have some resistance on the ring gear go around 3-4 times one way and 3-4 times the other. See what you get take shots of different parts of the ring gear around its full revolution so we can tell what the heck is going on in the pattern. :) JIm
 
well I am sure we all know the 741 is suppose to be the 10 bolt chevy rear of Mopar 8 3/4" rears. :)

Now the 489 and the 742 are some times a toss up

Some people think the 489 is better because of the big shaft 1.875 bearing but also takes more material out of the case which some say make it weaken the case...??? 489 uses a crush sleeve which in racing may not be the most desirable either.

742 case around here by most racing use it because it has the sold crush sleeve the shaft is still big but not to big to at 1.750 and conserder this a reason to help keep the case stable for hard drag racing.

My biggest pet peeve is MAKE CERTAIN YOU build the rear correctly and it will treat you right even the 741 for some mild track runs is NOT out of the question.

489 for me personally are easier to set the pinion because of the crush sleeve - the solid crush sleeve requires more work (assemble reassemble etc. ) to fine tune the preload correctly.

SO if you are going by size smallest to largest 741 742 489

742 489 will be always a personal choice I believe. Both will do the job. :)

:burnout:

Jim
J D Race
 
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