Rearend Whine after rebuild???

[chaztruett]

Finally got some time to get truck on road, slight whine, but no biggie at this point. Dang if I dont notice whine and gear noise in any car i get into now.

I still get a hum at 70 MPH, deffinatley drive train related. Ease down under 70 and it quits. Was told by another Old Hot Rod buddy that this was normal with these new gear sets, given time the gears will wear into pattern and hum will go away. The whine will never really go away.

Anyone else experience the hum? Bear in mind this is the second set of gears and second set of bearings.

thanks guys!
tt

[motorcritter]

Is the centre carrier bearing in good shape? Also, universal joints- known good or unknown? Sounds the rear axle is set up properly, you might want to eliminate any other driveline components as the source. An outside chance is tire noise. Once we had a Ford Taurus in the shop with an alleged front bearing noise, we replaced the bearing and CV axle at the customer's request. Noise still there- when test-driving, found out that the roof rack (for a sailboard) was the source of the noise- pulled it off, nice and quiet. Sometimes it's not readily apparent.
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[vettedrvr]

Originally Posted by chaztruett

Dang if I dont notice whine and gear noise in any car i get into now.
Was told by another Old Hot Rod buddy that this was normal with these new gear sets, given time the gears will wear into pattern and hum will go away.

thanks guys!
tt

Listen to your friend. It takes a few miles for the gears to wear a pattern then most of the noise will go away. I would check the rest of the drivetrain, too. Never know just when a 45 year old bearing will decide to stop being nice and round and turn into sharp little pieces.

[tcrist]

The quality of parts these days really gets me and then the idea of, it whines and will always whine, so live with it, does also.

If you bought a brand new pickup and the rear end whined, would you not take it back? Or not buy it!!!

Those have brand new gears in them also.

It used to be that you bought a gear set that was matched and you know what, it did not whine. That was the reason that you bought a MATCHED gear set.

Sorry, off my rant.

[chaztruett]

Originally Posted by motorcritter

Is the centre carrier bearing in good shape? Also, universal joints- known good or unknown? Sounds the rear axle is set up properly, you might want to eliminate any other driveline components as the source. An outside chance is tire noise. Once we had a Ford Taurus in the shop with an alleged front bearing noise, we replaced the bearing and CV axle at the customer's request. Noise still there- when test-driving, found out that the roof rack (for a sailboard) was the source of the noise- pulled it off, nice and quiet. Sometimes it's not readily apparent.
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No center Carrier bearing. All ujoints new. Running on lift and listen with stethoscope so no doubt coming from rearend. But you have some great things to check for sure!

[chaztruett]

Originally Posted by tcrist

The quality of parts these days really gets me and then the idea of, it whines and will always whine, so live with it, does also.

If you bought a brand new pickup and the rear end whined, would you not take it back? Or not buy it!!!

Those have brand new gears in them also.

It used to be that you bought a gear set that was matched and you know what, it did not whine. That was the reason that you bought a MATCHED gear set.

Sorry, off my rant.

I agree 100%! Im not sure if it has to do with offshore steel, gear cutting, or what. Have read that alot of this is due to trying to make the rearend stronger and last longer gives the resulting whine.

Hopefully when the gears wear in and polish themselves up it will be good. After 500 mile inspection on first gear set you could still see tool marks, gears had yet to wear into polished pattern, which means this steel is very very very very hard. (Im gonna say that OEM is somwhat softer) Shop replaced all bearings and a new gear set with a little better results. BL was set to 11/1000. Ive been into every part of cars and trucks by myself for many years but this is the first rearend, and thanks to all you guys I am learning alot.

thanks!
tt

[Keith Seymore]

After all this talk about rear axle whine I thought you guys might enjoy some "science" from one of the OEMs...

For your entertainment -

K

[Keith Seymore]

...

[chaztruett]

Hey Keith, that is awesome stuff. But, were do we get a dampener? Wouldn't that be kewl!

[fp1967]

I seen a cardboard tube inside of a driveshaft. I was told it was a fairly common thing to reduce ringing noises. I only seen this once, although I haven't cut all that many driveshafts apart. Anybody else ever seen this?

[Keith Seymore]

Originally Posted by fp1967

I seen a cardboard tube inside of a driveshaft. I was told it was a fairly common thing to reduce ringing noises. I only seen this once, although I haven't cut all that many driveshafts apart. Anybody else ever seen this?

Yes, but they didn't work very well.

That's why we quit doing it.

K

[Keith Seymore]

Originally Posted by chaztruett

Hey Keith, that is awesome stuff. But, were do we get a dampener? Wouldn't that be kewl!

We ended up using them on some C/K's (I think) and Astro/Safari (I'm sure).

Some time I'll have to tell you about tuning those.

K

[chaztruett]

OK guys, pulled cover and checked wear pattern which looked good. And backlash was showing 13 Thousandths. Pretty much no noticable whine, and no hum at 70mph.

Is it ok to live with the 13 thousandths? No doubt this gets tighter when everything gets hot.

thanks
tt

[Taibo]

Originally Posted by Keith Seymore

We ended up using them on some C/K's (I think) and Astro/Safari (I'm sure).

Some time I'll have to tell you about tuning those.

K

Astro or Safari??? Why tell us about those? If I owned one I would be ashamed to be seen in public. I might even slit my wrists.

[Taibo]

Originally Posted by chaztruett

OK guys, pulled cover and checked wear pattern which looked good. And backlash was showing 13 Thousandths. Pretty much no noticable whine, and no hum at 70mph.

Is it ok to live with the 13 thousandths? No doubt this gets tighter when everything gets hot.

thanks
tt

I am not worried in the slightest about 0.001 in. If it runs, does not whine let it be. If it begins to clunk when you lift your foot then it is time to shim it a little tighter.

[Keith Seymore]

Originally Posted by Taibo

Astro or Safari??? Why tell us about those?

Well....because we were talking about technical solutions that span across multiple GM product lines (S/T truck as well)....

It looked like some of the guys around here were interested in learning some "science".

Originally Posted by Taibo

If I owned one I would be ashamed to be seen in public. I might even slit my wrists.

You certainly seem to feel strongly about that.

K

[Katrina/10]

Cause I always wondered what that ring on the Astro driveshaft was, now I know.

[chaztruett]

Originally Posted by Katrina/10

Cause I always wondered what that ring on the Astro driveshaft was, now I know.

After you mentioned that, now I know exactly what ya'll are tlking about. Ha!