Post 4.10 install issue, what could it be?

[Testcase]

Just got the stang back from getting 4.10s put in and what I notice now is that when I take a turn, usually left, and I got some momentum going, I can hear a sound coming that wasn't there before. I can't tell if its coming from the front or rear, but it sounds like a rubbing or low whining noise.

I'm going to take the car back to where I had it done, but anyone have an idea of what it might be? At first, I thought it sounded like a tire rubbing when I turn, but there's no evidence of that and not 100% consistently occurring.

thanks!

 

[XTONKAX]

Whining usually means the backlash wasn't set correctly. I believe. Someone will correct me if I'm wrong. Did you have the bearings changed out at the same time? In any case, let us know what the installer says.

 

[340.29m/s]

hmmm, I would have to assume it is the gears. There is really no reason the for tires to be rubbing or anything else. Make sure they got the proper amount of fluid in!

 

[trinity_gt]

Sounds nuts but I'd have 'em verify the amount and type of oil (i.e. Traction Lok compatible...) they put in after the install...

 

[HIGDON]

Did they put a bottle of friction modifier??? That could cause your limited slip to chatter/whine when you take corners. . .. It's only $4 so grab a bottle and drop it in and see if that helps it out. Gear whine is consistant on accel or deccel.

 

[shane93nc]

Did they put a bottle of friction modifier??? That could cause your limited slip to chatter/whine when you take corners. . .. It's only $4 so grab a bottle and drop it in and see if that helps it out. Gear whine is consistant on accel or deccel.

So the gear whine is normal on accel and deccel?

 

[StangLou]

No, gear whine is not normal. What he is saying is that if you have gear whine it will be during both. If you have gear whine, they were not installed correctly

 

[twogts4us]

You can have some trannie gear whine with an aftermarket shifter, but this has nothing to do with new rear gears - you should not hear anything different from the rear...nothing. If you do, it's only a matter of time before it'll chew itself apart. Take all the advice above and take it back to your installer...something ain't right.
Backlash, gear oil, friction modifier.

 

[Testcase]

UPDATE:

Took it back yesterday and they thought friction modifier might be the cause. Picked it up after work when he called me as he said he took it for a spin and didn't hear anything.

BUT

Yeah, it's there still. It seems to have lessened I think. The way to *consistently* reproduce the noise is to be driving in a straight line and then start jerking the wheel to the side, like you're in a slalom. That seems to produce the noise every time. It sounds like some kind of rubbing noise more than anything, and occasionally, I can hear/feel a 'clunking' noise as well.

Normal driving to work today, there was no noise I think and everything felt normal.

The rubbing noise doesn't sound metallic really. And it's hard to tell where it's coming from, but its somewhere beneath me.

This started after the install, but I'm not even sure this *IS* a gears issue? All I can think is to take it back *again*.

Any ideas??

 

[Cobra Jay]

No, gear whine is not normal. What he is saying is that if you have gear whine it will be during both. If you have gear whine, they were not installed correctly

I work for Ford at the Axle Plant. I work with R&P for the F-series, but when it come to gear noise it doesn't matter what they are for. Maybe this will help.

Gear whine or humming is called Run-out. It actually could be caused by a few things. A nick or burr on either the ring or pinion, or not having the gears properly shimmed(bad drive and coast contact patterns) just to name a few.Also could be bad axle or carrier bearings.

If you get a humming during acceleration it's 9 times out of 10 the pinion isn't set right. On decel, it's usually the ring rear. Could be either one though.

Something is wrong, and I'd make him tear it apart and check. Bearings could have slop in them. If he wants to keep a good name for himself,he'll back up his work. Hope I helped.