69 300 rear noise

jmustian

jmustian

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I need some thoughts. I have the sure grip 8 3/4, 2.76 rear. On the road I have a noise from the rear of car. Jacked up and running in low, I have no noise. I put a pipe on the diff and the axle bearing housing and it all sounds smooth with no clicks or roughness.
I tried listening on turns and seems louder, by very little, on the right axle than left.
I pulled the wheel and drum and end play is snug but a question is, should there be play when turning axle front to back. I estimate and 1/8" play. Any suggestions helpful. Otherwise I'm pulling the right axle and putting new bearings on it. Thanks
 
Usually the wining noise of a wheel bearing starting to fail, wiil be noticeable at certain speeds. And in some cases gets louder when cornering.
When the sound is coming from your dif, I would assume it is noticeable at all speeds.
 
If it's a rear wheel bearing, when you load that side of the car, as in swaying it side to side, the noise will be louder when loaded and quieter when unloaded.

If you're going to do one bearing, might as well pull the other axle shaft out and LUBE that side too. Then also put new lube in the whole situation, with ltd slip additive (no matter what the lube container says).

Just some thoughts,
CBODY67
 
NY69 said:
Usually the wining noise of a wheel bearing starting to fail, wiil be noticeable at certain speeds. And in some cases gets louder when cornering.
When the sound is coming from your dif, I would assume it is noticeable at all speeds.
Click to expand...
The noise is constant at any speed.
 
I'm betting it's axle bearings.

More noise when cornering and no noise when no weight points to that.

Do yourself a favor and change both. It's hard to tell which one is bad by sound, and chances are the other bearing is going to fail. Buy the good Timken bearings too.
 
Would be a good time to go with Green Bearings. My passenger side bearing failed on my Newport. I made the switch with no regrets.
 
Ok. Another problem. There is a large axle seal that fits into the axle housing and I have plenty of them.
There is a smaller seal in the flange plate within the adjuster.
The FSM says these are both the same. However I have both in my hand that I took out and they are not.
The number on the inner seal matches the FSM number for the outer seal. No other numbers are listed for the adjuster seal unless I'm reading something wrong. There is another number listed but it appears to be for the 7 1/4 rear. Anyone have info on this adjuster seal?
 
jmustian said:
Ok. Another problem. There is a large axle seal that fits into the axle housing and I have plenty of them.
There is a smaller seal in the flange plate within the adjuster.
The FSM says these are both the same. However I have both in my hand that I took out and they are not.
The number on the inner seal matches the FSM number for the outer seal. No other numbers are listed for the adjuster seal unless I'm reading something wrong. There is another number listed but it appears to be for the 7 1/4 rear. Anyone have info on this adjuster seal?
Click to expand...
Timken #8704S for the outer seal and #8695S for the inner.

Lot's of guys just buy the package from Dr. Diff. Mopar Set 7 (A7) Tapered Axle Bearing Package

I've bought the separate bits and pieces because I'm cheap, but it really only saves a couple bucks. But I am that cheap...
 
jmustian said:
Not sure what they are but got some Timkins
Click to expand...
Green bearings are the sealed units, no adjusting required.

Kevin

1679968329.jpg
 
Big_John said:
I'm betting it's axle bearings.

More noise when cornering and no noise when no weight points to that.

Do yourself a favor and change both. It's hard to tell which one is bad by sound, and chances are the other bearing is going to fail. Buy the good Timken bearings too.
Click to expand...
Ok. Changed both sets of bearings and seals. Didn't like looks of either. Still have some noise. More even and consistent so I'm assuming the diff. New fluids but didn't know about Mopar additive till I reread this post. Guess I'll try that next. I don't hot rod this beast, just cruise haha
 
Carrier bearings and races look new. Added Ford modifier to rear but still have a noise. Not bad and runs fine but I can still hear it. I'm told it's the sure grip assembly and I should get it rebuilt.
 
Snotty said:
Would be a good time to go with Green Bearings. My passenger side bearing failed on my Newport. I made the switch with no regrets.
Click to expand...
I don't understand the green bearings. If they eliminate the right adjuster, why is an adjuster needed anyway and why can't I use a left axle flange and just eliminate the adjuster anyway?
 
The factory rear bearings are tapered rollers same as the front wheels. On the front wheel, you have an inner and outer bearing on each side and tightening the spindle nut pushes them together. Too tight and there is too much friction, too loose and things are wobbly. On the rear there is just one bearing on each side and the adjuster is like the spindle nut.

Mopar front wheel bearings.jpg
Mopar rear axle bearings.jpg


The "Green" bearings use round ball bearings with the bearing housing controlling the side to side movement, so the tolerances are built into the bearing already, so no adjustment is necessary.
 
D Cluley said:
The factory rear bearings are tapered rollers same as the front wheels. On the front wheel, you have an inner and outer bearing on each side and tightening the spindle nut pushes them together. Too tight and there is too much friction, too loose and things are wobbly. On the rear there is just one bearing on each side and the adjuster is like the spindle nut.

View attachment 684455View attachment 684456

The "Green" bearings use round ball bearings with the bearing housing controlling the side to side movement, so the tolerances are built into the bearing already, so no adjustment is necessary.
Click to expand...
Great info. Thanks
 
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