I recently rebuilt my 12 bolt rear end and it's make a slight humming sound.
It has a 3 series Eaton carrier, 3.42 Richmond gear and pinion & Strange axles. I did a complete rebuilt. Is it suppose to make that noise, or does it eventually go away. Can anyone help out, Thanks.

It sounds like the gears are not properly setup. Did you follow the instruction to the "T" that Richomond gave you as far as setting the rear up? That sound will never go away, if anything it will get worse over time until the gears fail.

Stop driving it now and re-check the tooth pattern. The pattern must be centered on the face of the ring gear tooth or the gears will make noise and eventually fail. If it's making noise now it will only get worse as the gears fail. They do not break in and get quieter.

Tom

Also to give a little more in depth of how a rear is set up in addition to the first post I made.....

You need to set the pinion depth first and foremost. The gear set should have come with the specs.
Once the pinion depth has been established, you need to set the pinion preload. You will need a torque wrench that measures in inch pounds, which I believe the reading should be 11 inch pounds if I'm not mistaken, but once again, it will be on the spec sheet
Once all that is complete, you have to set the backlash. This is how much play there is with the gears in regards to drive and coast positions. Most GM rears should be set at .004"-.008" of backlash. This is achieved by adding/subtracting shims from the sides of the carrier unit.
You will need a dial indicator to perform this operation.

Bottom line is, if you don't fix this problem now, it will get worse. Even if you redo the gears again so it's right, the whine will more than likely still be there or worse because the gearset has already begun to wear in.

I just refreshed mine today(12 bolt). If it is a 12 bolt you need to be sure the pinion depth is correct. and then the most important thing is backlash. Did you check your pattern? If you have new gears you should have a a centered pattern with .008 - 010 backlash. If old gears you will need to go closer to your old setup or the gears will ride too deep, venturing into gear contact that did not exist before. That is a problem and you will have issues like you stated. Your diff will fail if your pinion is set too deep into the crown or you have your backlash too tight.

Most folks underestimate the need to build a diff like an engine. They learned through the school of hard knocks!

Just MHO,

Charlie

Also to give a little more in depth of how a rear is set up in addition to the first post I made.....

You need to set the pinion depth first and foremost. The gear set should have come with the specs.
Once the pinion depth has been established, you need to set the pinion preload. You will need a torque wrench that measures in inch pounds, which I believe the reading should be 11 inch pounds if I'm not mistaken, but once again, it will be on the spec sheet
Once all that is complete, you have to set the backlash. This is how much play there is with the gears in regards to drive and coast positions. Most GM rears should be set at .004"-.008" of backlash. This is achieved by adding/subtracting shims from the sides of the carrier unit.
You will need a dial indicator to perform this operation.

Bottom line is, if you don't fix this problem now, it will get worse. Even if you redo the gears again so it's right, the whine will more than likely still be there or worse because the gearset has already begun to wear in.


I guess we posted at the same time but Blue's post is spot on.


Charlie

here check out this link might help.

http://www.usgear.com/ring__pinion_installation.htm

All of the above info is good, BUUUUUUUUUUUUUUT, there is one thing that no one has touched on so far (I don't know why?????).
Richmond gears have a reputation for sometimes being noisy. In the past, some customers have discussed this issue with Richmond, and Richmond's response has been less than satisfactory. Basically, their response is that is just how it is and it would be to costly for them to change or replace their equipment.
As a result, I don't buy Richmond R&P gears. Also, I have a strong preference for genuine GM gears. If a person can locate a good gear set of the ratio they desire, original GM gears are excellent. I frequently see used GM 12bolt gear sets at swap meets for VERY reasonable prices.

I completely agree that pinion depth is critical. But, it is not uncommon to get a rearend completely assembled only to discover that the contact pattern is not desireable (pinion was set according to specs). Thus, it is necessary to completely tear it down, change the pinion shim, and put it all back together. If you're familiar with setting up rearends, have patience and a press, it's not a difficult job, just time consuming.
I absolutely refuse to build a rearend in the car. Too much hassle, plus my knees are just getting too old for all that bending and getting up and down. I do 10-12bolt style rearends on a pair of jack stands and the real early rears (drop out center sections) on a fixture attached to the workbench. I don't know how much longer I can continue to do this stuff because I'm just not as agile as I used to be.

All of the above info is good, BUUUUUUUUUUUUUUT, there is one thing that no one has touched on so far (I don't know why?????).
Richmond gears have a reputation for sometimes being noisy. In the past, some customers have discussed this issue with Richmond, and Richmond's response has been less than satisfactory. Basically, their response is that is just how it is and it would be to costly for them to change or replace their equipment.
As a result, I don't buy Richmond R&P gears. Also, I have a strong preference for genuine GM gears. If a person can locate a good gear set of the ratio they desire, original GM gears are excellent. I frequently see used GM 12bolt gear sets at swap meets for VERY reasonable prices.

I completely agree that pinion depth is critical. But, it is not uncommon to get a rearend completely assembled only to discover that the contact pattern is not desireable (pinion was set according to specs). Thus, it is necessary to completely tear it down, change the pinion shim, and put it all back together. If you're familiar with setting up rearends, have patience and a press, it's not a difficult job, just time consuming.
I absolutely refuse to build a rearend in the car. Too much hassle, plus my knees are just getting too old for all that bending and getting up and down. I do 10-12bolt style rearends on a pair of jack stands and the real early rears (drop out center sections) on a fixture attached to the workbench. I don't know how much longer I can continue to do this stuff because I'm just not as agile as I used to be.


X2 richmonds suck

The pattern was centered and the backlash was set at .008.5, dont know what to do.
the Eaton required 4oz of Additive and the rest non synthetic oil, the Richmond required synthetic oil. I went with the Eaton carrier requirements.

I am getting the hawling sound when i lay off the gas pedal when I reach over 30mph

I would definitely re-check the pattern and backlash on the coast and drive side of the teeth, a 3.42:1 gear should not be making noise. It's an easy thing to do and will verify that everything else is right, a lot easier than re-building the whole rear end later.

I have heard of Richmond gears being noisy but more so with the higher ratios. The last rear end I set up had a Motive 4.11:1 gear and it made no noise at all.

Tom

Back in the day, and now-a-days, too, some gears weren't heat treated correctly. I always do this myself when I put a rearend together. I forget where I saw this, but it works.......

After you install a set of gears correctly so everything checks out, take it for a liesurely cruise for about 30 minutes, until the gears and fluid are hot.

Park it and let it cool for about 2 hours.

Take it for another easy drive until the gears are hot again. Do this over and over about four or five times and the gears are supposed to harden.

It sounds crazy, I know, but I've put in some cheap @$$ gear sets and they all are holding up. Even a set of Korean gears I put in an Impala SS the guy races on the weekends.

GM all the way theres nothin like GM parts:yes:

I never had a problem with Richmond gears being noisy....HOWEVER....I have broken 2 sets of them in a 7.5" 10 bolt posi I built for my 86 Cutlass. The first time the ringe gear sheared 5 teeth off, the second time, the pinion gear broke. THe contact pattern and backlash were spot on. That was the last time I ever bought Richmond Gears.