Fix slight whine with Richmond 3.42s?

[QytumHacker]

Any gear experts out there? I recently installed some 3.42 Richmond gears in my 8.5 10 bolt. Performed the proper break-in and kept it under 50mph and thought everything was great and quiet. After break-in I tried some highway speeds and have a slight whine at light throttle when maintaining speed between 50 - 55mph. Higher speeds it goes away. Not terribly loud and you can drown out with radio. Hasn't gotten any worst.

During the install the ring gear was scribed with .008 backlash. With my shims I was able to get .010 and called it a day as it was within the +.004 range. After 100 miles, I flushed the fluid and rechecked the backlash and gear pattern. Backlash is now .011 - .012 which I assume opened up slightly from regular wear and the gear paint being wiped off. I've seen a range of .008 - .012 as acceptable and I'm on the high end of the range.

My question is if I were to tighten up the backlash to .008, would it help remove the whine or do you think it could make things worst and I should leave it alone? I've heard Richmonds can make some noise so maybe its already good enough? Unfortunately, Richmond Gear has been unresponsive. Attached the gear pattern and the coast side might be a little high to heel.

https://photos.app.goo.gl/RQ3nYVNg3QHA225G6

 

[big gear head]

Did you get the bearing preload set tight enough? Your backlash should not have opened up like that, which makes me thing that the bearings are not tight enough. If you can remove the bearing caps and pull the differential out by hand then it's not tight enough.

Your pattern shows that the pinion depth is about .003 too deep.

 

[Lowend]

If I'm not mistaken, Richmond Gear has always been kinda noisey

 

[QytumHacker]

You definitely need a crow bar to get the carrier back out so they are tight. Did that too many times as the Richmond supplied shims were not the correct diameter and had to order a Yukon shim kit. Same for ring gear bolts, they provided the 5/8ths bolts with locking washers and the washers would split open. Replaced those with stock style bolts and loctite. Lets just say I'm not happy with the install kit but at least it came with Timken bearings.

The whine I'm sure is my fault though as this was my first rebuild attempt. I can't remember if I measured backlash with the cap bolts fully torqued so that may be where that extra .001 came from. I do know that my backlash readings at 50 miles and 100 miles have been the same and not getting worst. I believe you are correct in the pinion depth is probably a hair too deep. Nice to have extra eyes on the pattern. If its too deep, am I correct in assuming that tightening the backlash would just make things worst since it would bring the pinion in even closer? My looser backlash may be compensating for the pinion being too deep. If that is the case I may just run it as I would have to remove the whole rear again to do the pinion shim and at that point I would rather get a different brand of gear. A lot of lessons learned but I will say the whine is not that bad and in a very narrow speed range. I've heard much worst browsing youtube vids.

 

[Fbird]

If I'm not mistaken, Richmond Gear has always been kinda noisey

Being a Richmond fan....i would disagree with this statement. Richmond has always been my go-to gear source as They TYPICALLY have run well with no noticeable noises.

Now...you want NOISE...buy ZOOM!!!!!....lol The name says it all....cause thats what you HEAR when you drive

 

[DougD]

Bigger speakers and louder radio cure rear-end noise nicely.

 

[green 1977]

Bigger speakers and louder radio cure rear-end noise nicely.

or a less restrictive exhaust system

 

[badazz81z28]

Being a Richmond fan....i would disagree with this statement. Richmond has always been my go-to gear source as They TYPICALLY have run well with no noticeable noises.

Now...you want NOISE...buy ZOOM!!!!!....lol The name says it all....cause thats what you HEAR when you drive

I put Richmonds in the rearend I built too and zero noise...I think people like to blame gears for improper set-up or issues. I just went through this with a 9"...same thing noise!! "Ah its normal"...once I had a enough, I pulled it and checked it out and way too much BL. Moser rebuilt it and put a new gear in it and surprise no more whine. The gear was bad...but no sure way to determine what happened. No Pun intended, but this is why I rebuilt my own 10 bolt. You shot for .008" and .010" was "good enough"...probably what Moser did when they built the first one. I feel these things require precision.

OP, I think your noise (if its actual noise) is from set-up or the gear is simply failing. I would pull the differential and check pinion bearing pre-load and re-install the tighten up the BL. What did the gear oil look like?

 

[351maverick]

I've driven for YEARS on rear axles that whine like a roots blower

change the gear oil occasionally & it'll be fine

 

[QytumHacker]

OP, I think your noise (if its actual noise) is from set-up or the gear is simply failing. I would pull the differential and check pinion bearing pre-load and re-install the tighten up the BL. What did the gear oil look like?

Gear oil looks great no noticeable metal. No grinding noises of any kind and other than that small speed range its quiet. I don't blame the gears for the noise at its my first setup, just not happy with the install kit and support. The only thing usable from the install kit was the bearings. I've decided I'm going to open it back up this weekend and tighten up the backlash as I can do that with the rear in the car. Just crossing fingers it won't make it worst.