93 Rear end whine

Gs1987GT

Active Member
Sep 25, 2019
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As said, if the rear has been noisy for awhile, there's probably no curing it short of a rebuild and new gear set at this point.

I would only reccomend the FRPP gears, nothing aftermarket. I'd also use the factory style crush sleeve that comes with the gears. Getting pinion depth and backlash is critical. I rebuilt my rear with new carrier and pinion bearings and 3.55 FRPP gears. Since my car had the OEM 2.73s in it, i gave it a shot with the OEM pinion shim and that worked. Took me some time with a dial indicator and moving shims around and I finally came in at just under .012, which is the limit I believe (from memory) for backlash when using new carrier and pinion bearings (highly reccomend)

It's not for the faint of heart, but can be done with time and patience. I have a mechanical background which helped a lot. The key is ensuring everything is in spec before you call it done. My rear is factory quiet, no noise or unusual sounds.
 

Crigano

New Member
Mar 27, 2022
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Westchester NY
As said, if the rear has been noisy for awhile, there's probably no curing it short of a rebuild and new gear set at this point.

I would only reccomend the FRPP gears, nothing aftermarket. I'd also use the factory style crush sleeve that comes with the gears. Getting pinion depth and backlash is critical. I rebuilt my rear with new carrier and pinion bearings and 3.55 FRPP gears. Since my car had the OEM 2.73s in it, i gave it a shot with the OEM pinion shim and that worked. Took me some time with a dial indicator and moving shims around and I finally came in at just under .012, which is the limit I believe (from memory) for backlash when using new carrier and pinion bearings (highly reccomend)

It's not for the faint of heart, but can be done with time and patience. I have a mechanical background which helped a lot. The key is ensuring everything is in spec before you call it done. My rear is factory quiet, no noise or unusual sounds.
Thank you!
 

manicmechanic007

5 Year Member
Sep 26, 2017
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Run a pattern check on the gearset
Chances are your pinion depth is incorrect
On an 8.8 it's a little bitchy to set them up
You start with dummy bearings all around
Assemble it and check the pattern
Then if it is off you just change shims and re assemble it again and recheck the pattern
After you are satisfied with the pattern, you assemble it with new bearings and road test it
You might still have to play with it a bit more to get it perfect
As stated above, If the gears are Lo-Po all bets are off on noise
However if on coast or accell only, the whine can usually be solved by changing the pinion depth
Good luck
I put 4.56 Eatons in one of my ( 9 inch) pumpkins and they whine some
Car is so loud anyway, I worry not
 
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manicmechanic007

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1116-Yukon-9.75in-Ring-Pinion-Set-3.55-017.jpg
 
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manicmechanic007

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What I have found from the school of hard knocks
If it howls on coast, The pinion shim needs to be thicker
Sending the pinion closer to the ring
Yours, if it howls on accel, most likely needs a thinner pinion shim
Change it by about .008 each time
 
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Monday

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Feb 8, 2022
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So you think it’s the brand of gears that makes the noise?
When I put my 410s in, there was a definite 'whine'. I took it to the shop, and the mech there told me my backspace blah blah everything was all fine. The noise comes from the manufacturer - he said Ford gears don't do it; brands other than Ford seem to be the only cause for the whine.
 
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manicmechanic007

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I would have a different shop check the pinion depth
The whine should be there but not real bad
Most people (shops) have no pinion depth gauge for your 8.8
So, they either rely on a marking on the new pinion, or just guess as to which shim to use
They guessed way wrong on yours I believe
It might be time for you to learn to overhaul a rear end
It's really not that tough, especially if you get or make dummy bearings
 

Crigano

New Member
Mar 27, 2022
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Westchester NY
I would have a different shop check the pinion depth
The whine should be there but not real bad
Most people (shops) have no pinion depth gauge for your 8.8
So, they either rely on a marking on the new pinion, or just guess as to which shim to use
They guessed way wrong on yours I believe
It might be time for you to learn to overhaul a rear end
It's really not that tough, especially if you get or make dummy bearings
I’m not opposed to overhauling the rear end. I would do it if I had the tools. What do you think a shop would charge?
 

manicmechanic007

5 Year Member
Sep 26, 2017
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As far as special tools
All you need is a dial indicator on a magnetic base (to check the backlash)
You do need some heavy artillery (to crush the sleeve)(at the end when you assemble)
Normal labor about 900 (they are going to have to start over)
 
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Gs1987GT

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Sep 25, 2019
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As far as special tools
All you need is a dial indicator on a magnetic base (to check the backlash)
You do need some heavy artillery (to crush the sleeve)(at the end when you assemble)
This cannot be understated. I used breaker bars with pipes on them to extend length and had one braced on my chest attached to the pinion yoke to hold it so it wouldn't rotate (with the flange tool bolted to the pinion. It took a lot of force for me and I've been weight training for the past 30 years.

The other I pulled on the pinion nut to crush the sleeve. You need a beam style in. Lb. Torque wrench to measure the rotational force/preload on the pinion bearings and stop and check it often. You also need to go very slowly as the sleeve starts to crush as it comes up on spec quickly with very little movement of the pinion nut when the sleeve starts to crush. Go too far and your done. Have to take it back apart and start over with a new crush sleeve.

This was my first go at doing rear gears but I took my time and all went well. When I was in my 20s I had a shop in pottstown, pa do several gear swaps for me. He did a great job, but had all the Ford set up tools which makes it much easier. Worth it for him, not for me.

If I didnt have a lift and able to stand under the car to do the work I'd have paid someone to put the 3.55s in for me this time also.
 
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Crigano

New Member
Mar 27, 2022
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Westchester NY
This cannot be understated. I used breaker bars with pipes on them to extend length and had one braced on my chest attached to the pinion yoke to hold it so it wouldn't rotate (with the flange tool bolted to the pinion. It took a lot of force for me and I've been weight training for the past 30 years.

The other I pulled on the pinion nut to crush the sleeve. You need a beam style in. Lb. Torque wrench to measure the rotational force/preload on the pinion bearings and stop and check it often. You also need to go very slowly as the sleeve starts to crush as it comes up on spec quickly with very little movement of the pinion nut when the sleeve starts to crush. Go too far and your done. Have to take it back apart and start over with a new crush sleeve.

This was my first go at doing rear gears but I took my time and all went well. When I was in my 20s I had a shop in pottstown, pa do several gear swaps for me. He did a great job, but had all the Ford set up tools which makes it much easier. Worth it for him, not for me.

If I didnt have a lift and able to stand under the car to do the work I'd have paid someone to put the 3.55s in for me this time also.
I’m going to have a shop do it for me for sure. Lol
 
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