Got Me Worried About Gears, Is This A Problem Or Just My Imagination?

burnthefurniture · November 16, 2008

I just got a set of Yukon 4.11's put in my truck. I'm running stock size tires with them. Its a 10 bolt rear end. I have a slight whistling noise through all speeds and around 40-45 it howls just slightly then goes away. In all cases the noise is only on acceleration or deceleration. If I match the engine RPM to the rear end, it is quiet. I have heard people say they're having noises from their yukons and I've heard people say they are quiet as stock. Just wondering what anyone thinks. I would really hate to have to put the truck back in the shop if this is normal, but would kick myself if its not and I don't. Thanks in advance.

blackvmax07 · November 16, 2008

hey man i installed a 373 on my other truck with a locker and it whined, which is probably wat your hearing but after research i found that after market lockers are known for that so if you had a posi or locker installed at the same time thats probably wats goin on..

merlin5577 · November 16, 2008

Is the differential low on fluid?

66nova · November 16, 2008

I just got a set of Yukon 4.11's put in my truck. I'm running stock size tires with them. Its a 10 bolt rear end. I have a slight whistling noise through all speeds and around 40-45 it howls just slightly then goes away. In all cases the noise is only on acceleration or deceleration. If I match the engine RPM to the rear end, it is quiet. I have heard people say they're having noises from their yukons and I've heard people say they are quiet as stock. Just wondering what anyone thinks. I would really hate to have to put the truck back in the shop if this is normal, but would kick myself if its not and I don't. Thanks in advance.

I'm not going to say it's "normal", but I am also not going to say it's a problem. Who installed your gears? Gear installation can be a finicky job. It is critical, if you want quiet gears, to make sure they mesh correctly using shims. Setting up a set of new gears is actually easier because the gears have not been seated together yet and created a wear pattern. Even with a set of new gears, if they are not shimmed properly, they will whine (and yes it is almost alway when under acceleration/deceleration). A used set of gears has already created its wear pattern, so unless they are put in exactly how they were taken out some whining could be normal.

I would talk to your rearend guys and see if they think it is a problem, but it may be the way its going to be.

burnthefurniture · November 16, 2008

Is the differencial low on fluid?

I haven't cracked it open yet, I'm still in the first 500 miles of break-in. It is installed with the stock g80, I only replaced the ring and pinion. I have heard people say their yukons made a little noise, but others say they're quiet. I just am paranoid, this is the first time I've switched gears so I don't know if a little noise is normal for a gear swap to aftermarket or if its a problem.

burnthefurniture · November 16, 2008

I just got a set of Yukon 4.11's put in my truck. I'm running stock size tires with them. Its a 10 bolt rear end. I have a slight whistling noise through all speeds and around 40-45 it howls just slightly then goes away. In all cases the noise is only on acceleration or deceleration. If I match the engine RPM to the rear end, it is quiet. I have heard people say they're having noises from their yukons and I've heard people say they are quiet as stock. Just wondering what anyone thinks. I would really hate to have to put the truck back in the shop if this is normal, but would kick myself if its not and I don't. Thanks in advance.

I'm not going to say it's "normal", but I am also not going to say it's a problem. Who installed your gears? Gear installation can be a finicky job. It is critical, if you want quiet gears, to make sure they mesh correctly using shims. Setting up a set of new gears is actually easier because the gears have not been seated together yet and created a wear pattern. Even with a set of new gears, if they are not shimmed properly, they will whine (and yes it is almost alway when under acceleration/deceleration). A used set of gears has already created its wear pattern, so unless they are put in exactly how they were taken out some whining could be normal.

I would talk to your rearend guys and see if they think it is a problem, but it may be the way its going to be.

I got my gears installed at a local place called driveline specialties. I was told by another race shop that they didn't sound too loud (when he test drove my truck after tuning the ABS light out). The noise issue does not bother me if it is not a problem, but if it is, I obviously want it to be fixed. I believe I have a warranty on the labor, but its just a time issue obviously.

superjim · November 16, 2008

After checking to make sure the proper level of gear oil is in it....

if it is anything more than JUST BARELY AUDIBLE...

I would be taking it back and have them check the clearance on the gear teeth and the backlash of the gears.

Don't wait till your time limit guarantee runs out.

pm26 · November 16, 2008

Yes, this is a gear backlash adjustment issue. I had this before and I had one differential that whined all the time under steady load, the other whined only when unloaded, i.e. during deceleration.

burnthefurniture · November 16, 2008

Yes, this is a gear backlash adjustment issue. I had this before and I had one differential that whined all the time under steady load, the other whined only when unloaded, i.e. during deceleration.

Should I take it back to the place I got the install done? I would expect they ought to fix this since it was an install issue to begin with. I have definitely not driven it hard since the install during the break in.

Ryan00TJ · November 16, 2008

Sounds like a tight backlash issue to me. A properly setup R@P diff should not have an audible whine inside the cab at speed. Moser's 12 bolts for Fbodys are notorious for this whining but they claim they are set up with a tight backlash for added strength so its a give take relationship there.

I would take it back and have them check it out.

burnthefurniture · November 18, 2008

Sounds like a tight backlash issue to me. A properly setup R@P diff should not have an audible whine inside the cab at speed. Moser's 12 bolts for Fbodys are notorious for this whining but they claim they are set up with a tight backlash for added strength so its a give take relationship there.

I would take it back and have them check it out.

I am going this coming Thursday morning when they open to get it looked at. If I get there at 8, they ought to have more than enough time to get this resolved that same day? Would I be correct?