Grinding Noise 2000 Mustang GT

[bluemustang66]

Hello. Noticed a rear grinding noise in my 2000 Ford Mustang GT. Took my car to shop on Saturday and stayed from open to closing with promises of fixing b/4 end of day - I was there for 11 hours and they said that I needed new rear calipers, rear brake rotors, axle bearing seals, and axle shaft bearing. Also, that all else was fine in the rear end except for the fact that whom ever changed the rear axle fluid last did not use the correct weight synthetic fluid. Instead, regular engine oil. Picked up vehicle today with promise of 'fixed' and test driven with no grinding noise. Yet, I drove it and the noise continues and assistant manager agrees. Says to drive it 2 days and see if new fluid will help clear the noise as they have no other prognoses. All else is 'perfect' with no bearing issues nor metal shavings.

Any advice?

Are they right that having the incorrect rear differential fluid damaged my car?

Will the correct fluid correct the issue?

Had all new brakes installed recently, too, by Ford dealership where they 'topped off' the rear differential fluid w/ incorrect fluid, yet won't admit to it and cannot prove.

What else might it be?

Please excuse my whine, yet cannot afford to continue paying for repairs as I've 4 children (14, 8, 5, 1) and husband has not produced any child support.

Thank you

 

[Robs96]

First, how many miles do you have on this vehicle? Second, are you the original owner of this car ? Has there been gears added to the rear? Some inferior brands of rear gears can cause this sound (if indeed from the axle housing itself) and sometimes a poor installation of the gears can be a second source. Does the sound only occur when brakes are applied or at all driving times and does it get noisier the faster you go? Oil is heavier than diff lube. Even if they did add regular oil to it, if they were just topping it off then I doubt they added enough to already existing gear lube to make any difference unless you had a leak (notice any stains in the driveway where the rear sits?) and the case was almost empty Also, I fail to see why you would need those axle seals. All signs seem to point to a poor installation of gears and more than likely whoever did replace the gears, probably shouldn't be fixing cars. That or someone is/has been ragging the sh#t out of the car. Lastly, when the car was delivered as "fixed" what did they tell you they did to fix the problem, replace the brakes and that was it?

 

[bluemustang66]

Yes, original owner. Presently 87000 miles. No gears added to the rear. No, no ragging the sh#t out of the car. What they told me is that it was the rear axle and it was fixed. One technician drove it and I asked to ride with, yet due to "liability" was not allowed. Technician said it has the "normal car sounds", then I insisted to ride and heard the grinding noise. Left in my car and listened while driving across street to p/up Enterprise rental car agent and deliver to rental car. Yet, my brake light would not turn off. So another technician fixed and drove my car for about a mile and said yes, he heard the noise and was totally lost as to why. He again attributed the noise to prior shop using incorrect rear differential fluid. (This shop is now no longer same ownership). The technician said he'd call his manager, who returns on Thursday, and continue to research the problem and will call me today. This has not occured.

 

[Robs96]

No surprise on the return phone call. Lets look at the brakes. You recently had them serviced. Did the vehicle make this sound prior to having the brakes changed and who did the service? Then you pick up the car and the brake light is on. What did they do to fix it?

Now lets look at the rear axle. There is some mystery here. You are the original owner. Have you prior to these "repairs" ever had the rear axle fluid drained and refilled? I'm assuming so but why did you have it changed? Did this sound start after that service? What was the interval between this place that is out of business and when you just recently took it to Ford in relation to the noise starting? Did Ford replace the fluid? Another thing I have a problem with this is did Ford tell you the fluid was incorrect before repairing/replacing fluids? If you just removed the fill plug in the axle to check it, you would not be able to tell readily the type of fluid. I changed the rear axle fluid in my Stang at 100k and you couldn't tell what the hell it was aside from it smelled like diff lube. I will also add that as the car gets older it is not uncommon to hear gear noise (they wear also).

 

[bluemustang66]

Well, after picking up car "repaired" on Monday, Oct. 8, the "grinding noise" continued and the new left rear caliper failed. Thus, brake fluid leaked and had to use emergency brake to stop car b/4 driving through the rear of my garage. Car towed, legal threats, calls to district manager, witnesses, photos, missed work, etc., they agreed to pay the correct repairs (ring and pinion bearing assembly), tow, rental car. The repairs took 3-days.

Yet, now, at times the car 'squeaks' on bumps. Why could this be? They won't take my calls. May file report with BBB and Attorney General.

 

[John00Stang]

Id be scared to let them touch my car ever again..i would threaten them with a lawyer etc etc.. try to get my money back completely and take it to a reputable shop.
Now i get that they can't fix the noise.. but the fact that they (fixed) your brakes and then your brakes failed could have possibly been a very nasty accident. Good luck with it, and let us know what comes of it.

 

[Robs96]

Yes you need to contact the BBB. There is clearly something not adding up hear and you will not get anywhere with a dealership. The squeaking you here is most likely from your suspension, your car is seven years old. Since you had the other problem though, you will be more susceptible to other sounds the vehicle makes. I would not worry about the squeak. If the dealership screwed up the vehicle, my advice, take it to another dealership and tell them what happened. Dealerships LOVE to outdo one another and in a case like this, if another dealership will provide in writing that the other business messed up, then you could have some money due to you I think they pulled some shady practices on you, personally speaking. I remember as a kid my grandmother taking a vehicle to firestone for tires and they sold her a water pump, rack and pinion, and new brakes on top of tires for a Nissan Maxima station wagon that was an 1983 model and this was in 1985. Some things just don't change.

 

[COramprat]

The squeaks over bumps don't sound to be much of a problem. Does it sound like bedsprings? If so it is just worn isolators. Mine has been doing this for 3 years.

Frustrating thing is I think whoever changed your differential screwed up if they just used regular oil. Hopefully those issues are fixed. next time come here and ask a few questions. Most of the time you'll get some good info to bring with you to the mechanic and you will sound a bit informed so they don't try to rip you off.

The other concerns...is the grinding gone now?