Just picked up my car after having TSB 05-20-2 done for rear axle whine. Before I took it in, it was a faint but noticable whine noise around 65-75 mph, only with foot on gas. After the "fix"? 1000 times worse! That is not a exaggeration. Only now it's on decel (foot off gas). All the way from 65 down to about 30 mph - louder around 45 mph. I swear at 45 mph it sounds like a cop has his sirens on behind me now. WTF! Don't they even test drive these things when they fix them?!? It's going back.

So - anyone else have the same experience? Was it ultimately fixed? Did they just redo the TSB?

 

Buy 4:10 gears and have a good installer put them in.

 

Yeah, pretty much same experience - karma was on my side today, though (so far).

Back in April I took it in to the dealer for the same TSB/problem. They redid the ring and pinion per the TSB. Whine was even worse. What was a slight whirr/whine at 55-65 was now a howl from 45 to 70, and then the thing groaned if I either stomped on the gas or lifted off. Took it back in July. They took the differential back out and "everything was within specs", but the carrier side bearings were abnormally worn. So they replaced those - the gas pedal sing along stopped but the constant howl from 45-70 was still there. Sometimes I could hear it at 30 MPH, too.

I took it to a different Ford dealership last week (though owned by the same guy, just a different suburb). Tech took it for a spin and said the last guy obviously put it in wrong for it to make that much noise. He said some techs are lazy and set the backlash somewhere within factory spec and let it go, without really dialing it in using gear marking compound. If it still makes noise - lazy tech will just say "Well, I set it within specs so what could be wrong?" He said he would take his time with it, dial it in real good and get it done right.

They had to order a new ring and pinion so I took it back today. He spent about 6-7 hours on it total. My repair order today says "Prior TSB repair set improper backlash, too much pinion depth, and insufficient pinion preload." Jeez - what part of the TSB did he do RIGHT? He also noticed my differential retaining bolt (P/N 4241) was rounded off by the last tech and replaced that. (you're really not supposed to reuse them in the first place).

So far - fix seems great, super quiet all the time. But I have not pushed it past 60 MPH or driven for more than 10 minutes - I'm doing a "proper" break-in, though probably not needed as they may have already done it (they put 60 miles on the car).

So...hopefully my luck holds out. If it does I'm going out of my way to thank the tech and service advisor. Goes to show its really who does the work. Not every dealer or tech is the same.

 

Even brand new FRPP gears will whine like a banshee if the installer does a crappy job.

 

How much would a good installer charge to install 3:73 or 4:10 gears?

 

Well, got it back after second attempt. Significant improvement, but still hear a whine on coast (decel) between 40-60 mph - definitely noticable and not there before I brought it in. I also now notice a whirring type sound coming from under the gear shift (auto tranny) while in park - could that be related somehow?
So, now what? Do I:
- keep going back until they get it right?
- try a different Ford dealership?
- take it back and have them install FRPP 3.73 gears in hopes that they won't whine?
- give up on Ford and just pay a reputable installer to put in 3.73's?
I'm not asking for perfection here. I just want the car to be at least as quiet as when I brought it in.

 

My local Ford dealer installed 4.10s in my '01 GT (this was back in '02) for $200 labor....I provided the gears.

 

Take it somewhere that will do it right - either another Ford dealer under warranty or a performance shop that will put in the 3.73's. It's obvious to me that your current dealer doesn't know what they are doing since they have tried twice and still can't get it right. (like my experience).

I'm going on one week so far with mine and it is still dead quiet. If done right it shouldn't make any noise, period.

 

It's going in Monday for try #3 at the same dealership. If they can't get it right, I'll take it to another dealer or demand they pay for a performance shop to do it.

 

4 times and you might get a new car under the lemon law.

 

Differentials really separate the men from the boys. Your ears know immediately if yours was worked on by a man or a boy.

 

Is it safe to get the 3.55:1 rear axle upgrade package from the factory?

 

Being that this isn't a major mechanical, car-doesn't-run sort of problem, I doubt I'll lemon law it. I just put a clear bra on it, so I'd be out $500 for that if I did.

I took it in Monday for try #3. They called and said they'd like to keep it for a couple days to really attend to it and get it right. Would've been nice if they did that the first time or second time. I have my fingers crossed.

I stopped in Carolina Mustang Performance yesterday, and they recommended a couple guys in the area. So if the dealer can't get it right, I'll push for Ford to pay an outside shop to do it.

 

Sorry you're having so much trouble getting this fixed .

I recall seeing on either this site or another one (I do stray when TMS is down) that on a TSB for this it mentions some sort of gear lube as a possible fix. I couldn't find it just now by doing a search on TMS.

Apparently the improper lube is sometimes applied at the factory and this alone has solved the problem for some vehicles without having to replace gears. Sorry that I don't have more complete info on this. Just wanted to give a heads up for a possible solution.

 

Thanks, I'll look for it. If you find it, please let me know.

 

I sent you a PM on this.

 

I heard from a fellow CV owner that his GT had the same problem (crack snapple and pop while turning, whining, groaning, etc...) and the correct amount of friction modifier solved the problem.

If it were my GT and it had the 8.8" rear, I would remove the fill plug and extract some gear oil if it is full (about 4 oz worth). I would then buy a 4 oz bottle of FM and squirt it in there and see if it fixes the problem.

Alternatively, you could just change the gear oil yourself (grab 2-3 qt of full synthetic 75W-140 formulated for limited slip differentials, and add 4 oz of FM). I think the owner's manual said to use 75W-140 synthetic?

 

I don't think the friction modifier is going to correct the whine. The dealer would have added it when they rebuilt the rearend.

 

In that case, its gotta be the pinion gear. I've swapped out the carriers a few times on my 8.8" and set the backlash at different values (from tight to OEM-spec loose) and never experienced whine/howl/groaning. I never touched my driveshaft or the pinion gear.

 

Just got it back, Definitely improved, but STILL THERE. Enough that I can tell exactly when I'm doing 50 mph without looking at the speedometer. Man this is frustrating.

This time they found "the pinion bearing had slight wear", so they installed a new one and reset the ring and pinion. The parts listed are cup, cone, spacer, oil, additive (XL-3), and shim.

I'm gonna drive it a few days to make sure I'm not being overly **** about it. Next step is a different ford dealer I guess.