New Gearset High Pitched Squeal

[randy500]

Your current pattern looks acceptable and moving it a little i dont think is going to make a real difference. I cant think of what else might cause the noise though.

[randy500]

On the coast side of the last picture you can see the smooth spot worn into the gears from driving it, do you see that on the other side? Are you sure the backlash was correct and the same all the way around? No Runout? Pattern looks possibly a tad deep into the gear root.

[cebra]

Originally Posted by randy500

On the coast side of the last picture you can see the smooth spot worn into the gears from driving it, do you see that on the other side? Are you sure the backlash was correct and the same all the way around? No Runout? Pattern looks possibly a tad deep into the gear root.

The same all the way around? Does that mean to measure on a couple different places on the ring gear? We just measure it where it was at. Here are the pics after adding a .004" shim, Richmond says it looks good as far as the pattern goes but maybe it is a little deep (backlash too tight)?

[randy500]

Yes check backlash at 4 spots, checking for runout.
Pattern does look good, as far as depth to root, your prob best judge in person, helps sometimes to clean marking compound from root with a q-tip to see if centered.

[randy500]

Just looked at pattern again on page 1, current pattern is much better. I would run it if backlash is good and no runout.

[cebra]

Last pattern we sent to Richmond (same shim as the last pics I posted just all bolted up). When I saw this, I didn't like the pattern as it looks too far to the outside of the ring gear vs the crappy thumb size pattern pic in the manual but Richmond said yup that is it. Drove it down the road, squeals like 1 million shrieking children...actually sounds more like a very loud, very high pitched whistle. I mean very loud as in probably the loudest single noise I have ever heard in my life. One takeaway is that the squeal has seemed to move from starting at 40mph to more like 55mph so that may change something. The shop thinks it is a bad gearset as they are up in arms, I am considering swallowing my now ~$2K I have in this and put my 3.07/GM Carrier back in, whatever work I have to do I will need to do myself now since the shop has chalked it up to a parts issue and I am 50/50 on that. In hindsight, I should have just bought a new rearend and dropped that in myself. Specs below for any rearend experts to comment:

Pinion shim - .034
Backlash - .0085
Pinion Preload - 25 in lbs

[cebra]

The shop put a stethoscope on the rearend and seems to think the pinion nut is too tight and the squeal is coming from the pinion bearings being sandwiched. They said they found somewhere that the 20-25 in lbs spec in the GM manual may be incorrect for the new bearing set (which had no torque spec) and are going to set it at ~12...anyone else run into this on a new gear set?

[randy500]

Gm shop manual has a spec for bearing preload, new and used, i haven't looked it up in a while but its there.

Too much preload is not usually a problem, i have overshot the preload many times and they run out fine, the bearings are relatively large and in a gear oil bath at all times so they can take a lot of load.
High pitched squeal now that i think about it sounds like stamped steel rubbing on Something, could the oil slinger on the pinion flange be rubbing on something?

I also had a driveshaft carrier bearing oil slinger get loose and make a squealing sound once.

[randy500]

What other work was done at the same time?
Driveshaft?
axle shafts?
5 lug conversion?
Anything?

How about this...remove the axle shafts, spin it up without them
Remove the carrier and spin it up again
Try to isolate the noise to the ring and pinion or bearings

[cebra]

Originally Posted by randy500

What other work was done at the same time?
Driveshaft?
axle shafts?
5 lug conversion?
Anything?

How about this...remove the axle shafts, spin it up without them
Remove the carrier and spin it up again
Try to isolate the noise to the ring and pinion or bearings

We did replace the axle seals/bearings the first go around and one axle was pretty worn so we replaced that between the 2 times where it squealed (squealed before and after replacing the axle). I think they are already blowing it apart again and I don't have a warm fuzzy feeling about backing off the preload to 12-15 in lbs. The 1971 GM manual says it needs to be 20-25 and I have heard that it will end up in the 12-15ish range after break in.

[randy500]

exactly right on the preload before and after...
Maybe they are saying pinion was set to spec but they know its actually way tighter and are now finally going to back it off....

Backing it off is a lot of work and requires a new crush sleeve, probably why they didn't so it before. Starting the crush is a real bear in terms of force and tool set up.

[71meangreenc10]

If you do decide to put another set of gears into it look at Motive Gears. I went down the Richmond road and will never do it again. I have a Motive set in my GMC and they have been great.


Smitty

[cebra]

Originally Posted by 71meangreenc10

If you do decide to put another set of gears into it look at Motive Gears. I went down the Richmond road and will never do it again. I have a Motive set in my GMC and they have been great.


Smitty

Thanks, they backed off the pinion to 6 in lbs to purposely set it super light and no change in sound so I called Summit and they are sending me a Motive and taking the Richmond back. The shop has to redo the crush sleeve to get it to 20 in lbs again so minimal work to change the gears out.

[GASoline71]

Originally Posted by 71meangreenc10

If you do decide to put another set of gears into it look at Motive Gears. I went down the Richmond road and will never do it again. I have a Motive set in my GMC and they have been great.


Smitty

Been using Richmond gear sets for 30+ years with not a single issue. Not saying there can't be a bad apple in the bunch, but... I don't think I've been lucky either.

Gary

[cebra]

Originally Posted by GASoline71

Been using Richmond gear sets for 30+ years with not a single issue. Not saying there can't be a bad apple in the bunch, but... I don't think I've been lucky either.

Gary

Have you used Excel by Richmond by chance, in hindsight I have not read very good things about them and there is a massive price discrepancy between those and regular Richmond gears so they may just be of lower quality? The guy doing the work has done a lot of gear sets on various vehicles (more of a FCA than GM guy though) and as much as I thought he/we set it up wrong, we have had it in and out with various changes 4 times now as neither of us wanted to believe it was a parts issue. Once Richmond confirmed the pattern and backlash through pics and we did the pinion load change for good measure I have given up and chalked it up to a parts issue. When we called Richmond they said "gears make noise, send it back to Summit" so that is what I am doing, the noise is horrific is all I can explain it. Not a whine, not a clang, ear piercing whistle noise that sounds like it may be the noise that busts glass. I can feel it through my entire body sitting in the seat at 60mph. Now if the Motive makes the same noise...well after I puke a bit I will replace the pinion bearings a 3rd time and the carriers a 2nd and say the Richmond gears were fine. Will update by Monday on status of new gears.

[cornerstone]

This thread is making me nervous too! I'm a ways off before a test drive but I set up my gears myself for the first time.

[GASoline71]

Originally Posted by cebra

Have you used Excel by Richmond by chance, in hindsight I have not read very good things about them and there is a massive price discrepancy between those and regular Richmond gears so they may just be of lower quality? The guy doing the work has done a lot of gear sets on various vehicles (more of a FCA than GM guy though) and as much as I thought he/we set it up wrong, we have had it in and out with various changes 4 times now as neither of us wanted to believe it was a parts issue. Once Richmond confirmed the pattern and backlash through pics and we did the pinion load change for good measure I have given up and chalked it up to a parts issue. When we called Richmond they said "gears make noise, send it back to Summit" so that is what I am doing, the noise is horrific is all I can explain it. Not a whine, not a clang, ear piercing whistle noise that sounds like it may be the noise that busts glass. I can feel it through my entire body sitting in the seat at 60mph. Now if the Motive makes the same noise...well after I puke a bit I will replace the pinion bearings a 3rd time and the carriers a 2nd and say the Richmond gears were fine. Will update by Monday on status of new gears.

I have never used anything other than "regular" Richmond gears sets. Man it sucks you are getting that high pitched whine after it's all set up. I wish I could add more to help you out in your situation.

I tried Motive Gears (cuz they were cheaper) in a 1979 K25 14 bolt FF some time ago, and they made a horrible whine. But it was the typical whine you would think when hearing "gear whine"... not the screech like you mention. I ran those gears for quite a while and the whine subsided over time, but was still faintly there.

Gary

[cebra]

Originally Posted by GASoline71

I have never used anything other than "regular" Richmond gears sets. Man it sucks you are getting that high pitched whine after it's all set up. I wish I could add more to help you out in your situation.

I tried Motive Gears (cuz they were cheaper) in a 1979 K25 14 bolt FF some time ago, and they made a horrible whine. But it was the typical whine you would think when hearing "gear whine"... not the screech like you mention. I ran those gears for quite a while and the whine subsided over time, but was still faintly there.

Gary

Yeah, the regular Richmond gears are almost double the price of the Excel by Richmond ones so I assume there is a significant difference in materials, quality, etc.

[Jrainman]

Originally Posted by cebra

The shop put a stethoscope on the rearend and seems to think the pinion nut is too tight and the squeal is coming from the pinion bearings being sandwiched. They said they found somewhere that the 20-25 in lbs spec in the GM manual may be incorrect for the new bearing set (which had no torque spec) and are going to set it at ~12...anyone else run into this on a new gear set?

I have been following this thread and ,I am no expert , I have 5 rebuilds under my belt 3 gm and 2 bmw in proberly a 15 year span , and yes GM truck rear specs are 20- 25 inch pounds for both 12 and 10 bolt, and everytime I did a GM rebulid I set them at 16-19 inch pounds , the 10 bolt was set at 16 and the 2 12 bolts set 18 and 19 inch pounds,this seemed to be the sweet spot for me , I had no issues at all with any of the rebuilds I did.

[71meangreenc10]

Originally Posted by GASoline71

Been using Richmond gear sets for 30+ years with not a single issue. Not saying there can't be a bad apple in the bunch, but... I don't think I've been lucky either.

Gary

Gary,

From what I read when I had my experience there were quite a few Richmond Orchards that must have had a bad year.....

Smitty

[71meangreenc10]

Originally Posted by cebra

Thanks, they backed off the pinion to 6 in lbs to purposely set it super light and no change in sound so I called Summit and they are sending me a Motive and taking the Richmond back. The shop has to redo the crush sleeve to get it to 20 in lbs again so minimal work to change the gears out.

I have put 3.42 Motive sets in quite a few 12 bolts and I haven't had any issues with them.

Smitty

[cebra]

Originally Posted by 71meangreenc10

I have put 3.42 Motive sets in quite a few 12 bolts and I haven't had any issues with them.

Smitty

Good to hear, should know by Monday...fingers crossed.

[Quikshft]

Getting ready to install 4:10 gearing in my 71. Will admit the outcome of the situation topic of this thread will carry some weight in my choice of components.

[Steeveedee]

I rebuilt the diff in my '64 Impala (3.9X posi) but don't remember for certain where I bought the parts, but probably from the local Chevy dealer, since I was a mechanic at the time. Had to make a spanner and some other tool to get it done, but it was dead quiet when I was done. Sorry to see you having so much trouble.

[cebra]

I put the new Motive Gear set in, same backlash, pinion preload, bearings, and from what I see an identical gear pattern...whisper quiet. I wish I had taken a picture of the gear sets side by side, the visible difference was astonishing really. The motive gears were clearly more robust and the gear "cut" looked much more precise for lack of better words. The pinion gear itself was about 0.5" thicker with much deeper gearing. Anyways, all broken in and running perfectly. I would advise not to go with Excel by Richmond and if you do order another gear set and set them side by side before you choose, the difference is clear. There is a definite reason they are 50-75% of the price of Motive, Richmond (originals), and USA Gear.