2012 Boss rear axle/brake noise and tranny leak
4/28/11, 04:30 PM
#1
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2012 Boss rear axle/brake noise and tranny leak
My car developed a slight chirping noise from the left rear brake/axle area. 
The noise was consistent with wheel revolution and actually got much louder with harder brake pedal application until it actually goes away. We did a state inspection at my work and also noticed a gear oil leak from the trans. I made an appointment with my local Ford dealer...
So by the time my appt came around the weather was warm and the chirping was embarassingly loud, so I knew something OTHER than debris on my brake pad was causing the problem.
The lead service writer had the shop foreman ride with me to show him the noise and he said he will get me when the car is on the lift to explain what he finds. So a hour goes by and they page me, he expained the hub was not pressed onto the axle shaft correctly and as such the whole wheel/tire/brake/rotor assembly was wobbling slightly causing the chirp as the rotor hit the brake pad. They are replacing the left rear axle assembly along with the rear diff fluid (needed to be done at 1,000 miles anyway
)
As far as the trans he showed me where the fluid was leaking out the vent tube on top of the tranny. I let them know that the trans was hard to shift into 2nd when cold and they said they will be replacing the gear oil per a TSB, and making sure the level is correct. They said we will watch the vent for futher leakage. BTW I had them change the oil filter only and top off the oil. It only took 1 quart of oil with the filter change...pretty low consumption for 1300 miles!!
Great service for a really dumb issues...
The noise was consistent with wheel revolution and actually got much louder with harder brake pedal application until it actually goes away. We did a state inspection at my work and also noticed a gear oil leak from the trans. I made an appointment with my local Ford dealer...So by the time my appt came around the weather was warm and the chirping was embarassingly loud, so I knew something OTHER than debris on my brake pad was causing the problem.
The lead service writer had the shop foreman ride with me to show him the noise and he said he will get me when the car is on the lift to explain what he finds. So a hour goes by and they page me, he expained the hub was not pressed onto the axle shaft correctly and as such the whole wheel/tire/brake/rotor assembly was wobbling slightly causing the chirp as the rotor hit the brake pad. They are replacing the left rear axle assembly along with the rear diff fluid (needed to be done at 1,000 miles anyway
)As far as the trans he showed me where the fluid was leaking out the vent tube on top of the tranny. I let them know that the trans was hard to shift into 2nd when cold and they said they will be replacing the gear oil per a TSB, and making sure the level is correct. They said we will watch the vent for futher leakage. BTW I had them change the oil filter only and top off the oil. It only took 1 quart of oil with the filter change...pretty low consumption for 1300 miles!!
Great service for a really dumb issues...
4/28/11, 05:14 PM
#2
Glad it wasn't serious and I am glad they took care of it properly. Good service story. We usually only get the bad stories. Not that there is anything wrong with that - it is good to know what to look out for, but a nice story once in a while is refreshing.
4/28/11, 06:10 PM
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Is there really a hub that presses on the axle? Don't have an exploded view to reference, but doesn't the rotor hat register against the axle flange? Assuming the axle is one piece, and the rotor mated flat against the axle flange, then for rotor/wheel/tire assy wobble to occur, the axle flange would have to be defective....
4/28/11, 06:16 PM
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Originally Posted by 68asedan
Is there really a hub that presses on the axle? Don't have an exploded view to reference, but doesn't the rotor hat register against the axle flange? Assuming the axle is one piece, and the rotor mated flat against the axle flange, then for rotor/wheel/tire assy wobble to occur, the axle flange would have to be defective....
Last edited by Big Vito; 9/5/11 at 04:57 PM.
4/28/11, 06:18 PM
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What am I missing here.....since when does an 8.8 have a hub assembly (like the IRS)?
In general and not owning a Mustang, yet:
Axles rotate on a bearing inside each end of the housing. A seal is also press fitted to keep the oil in and everything else out. Axle is held in by a C-clip. Brake assembly is bolted to the axle housing. If the bearing was not press fitted correctly, it still should not have made a difference on the axle rotation, at least not near enough to cause the rotor to contact the caliper. The brake pads wear to the position of the rotor in reference to the caliper. I don't see how the improperly pressed bearing affects the sound your describing. A bent axle or axle tube housing does. I can imagine that a improperly positioned bearing could scar/groove the axle making a grinding noise. If anything, leaking diff fluid would be a sign of an axle bearing and seal failure. Did you have any of that?
Dave
In general and not owning a Mustang, yet:
Axles rotate on a bearing inside each end of the housing. A seal is also press fitted to keep the oil in and everything else out. Axle is held in by a C-clip. Brake assembly is bolted to the axle housing. If the bearing was not press fitted correctly, it still should not have made a difference on the axle rotation, at least not near enough to cause the rotor to contact the caliper. The brake pads wear to the position of the rotor in reference to the caliper. I don't see how the improperly pressed bearing affects the sound your describing. A bent axle or axle tube housing does. I can imagine that a improperly positioned bearing could scar/groove the axle making a grinding noise. If anything, leaking diff fluid would be a sign of an axle bearing and seal failure. Did you have any of that?
Dave
Last edited by iDrive; 4/29/11 at 07:50 PM.
4/29/11, 02:38 PM
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4/29/11, 04:51 PM
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What are you saying? You burned a quart of oil in 1300 miles???? Or are you saying a quart of oil leaked out just doing a filter change. I would hope you're not burning that much oil in a brand new engine?
4/29/11, 07:45 PM
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It used about 1/3 of a quart and the rest was filling the new filter and replacing the leaked oil. I wanted a new filter on because they advised to wait at least 5,000 miles before changing the oil. I asked them to at least change the filter as I wanted to make sure it was efficiently filtering until I change the oil at 5k
4/30/11, 09:14 AM
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My friends Shelby experienced something similar. It turned out to be a faulty or bent axle retainer clip. It allowed the axle to move outward and was rubbing on the caliper or brake pads. He said it was making alot of grinding noise. They rebuilt the rear end and no problems since.
Mike
Mike
5/4/11, 07:27 PM
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Picked up the car tonight and was really happy. the car was locked in the service drop off garage with no other cars around it and they didn't run it through their automatic brush wash!! The paperwork says the tech found the left axle had 0.015 runout and replaced the shaft, bearing, seals,, and diff fluid. The also did the trans fluid TSB by replacing the factory oil with dual clutch fluid. The cars shifts so much nicer now...feels like a new trans, no notchiness, and feels more "solid"! Overall a great experience, and btw the charge to replace the oil filter and 1 quart was $36...not bad in my book!
5/5/11, 09:59 AM
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So I'm wondering what's the down side of the dual clutch trans fluid? If the trans works better with that fluid, why doesn't the trans come from the factory with it in it? Should we all be changing our trans fluid to the dual clutch fluid?
5/5/11, 11:54 AM
#19
I would like to know if all newer Mustangs have the new fluid, if not then Ford does not think it is a better fluid but one that helps with a certain problem that not everyone sees.
Last edited by 2012YellowBoss; 5/6/11 at 07:14 AM.
5/6/11, 06:35 AM
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My car developed a slight chirping noise from the left rear brake/axle area. The noise was consistent with wheel revolution and actually got much louder with harder brake pedal application until it actually goes away. We did a state inspection at my work and also noticed a gear oil leak from the trans. I made an appointment with my local Ford dealer...
So by the time my appt came around the weather was warm and the chirping was embarassingly loud, so I knew something OTHER than debris on my brake pad was causing the problem.
The lead service writer had the shop foreman ride with me to show him the noise and he said he will get me when the car is on the lift to explain what he finds. So a hour goes by and they page me, he expained the hub was not pressed onto the axle shaft correctly and as such the whole wheel/tire/brake/rotor assembly was wobbling slightly causing the chirp as the rotor hit the brake pad. They are replacing the left rear axle assembly along with the rear diff fluid (needed to be done at 1,000 miles anyway)
As far as the trans he showed me where the fluid was leaking out the vent tube on top of the tranny. I let them know that the trans was hard to shift into 2nd when cold and they said they will be replacing the gear oil per a TSB, and making sure the level is correct. They said we will watch the vent for futher leakage. BTW I had them change the oil filter only and top off the oil. It only took 1 quart of oil with the filter change...pretty low consumption for 1300 miles!!
Great service for a really dumb issues...
The noise was consistent with wheel revolution and actually got much louder with harder brake pedal application until it actually goes away. We did a state inspection at my work and also noticed a gear oil leak from the trans. I made an appointment with my local Ford dealer...So by the time my appt came around the weather was warm and the chirping was embarassingly loud, so I knew something OTHER than debris on my brake pad was causing the problem.
The lead service writer had the shop foreman ride with me to show him the noise and he said he will get me when the car is on the lift to explain what he finds. So a hour goes by and they page me, he expained the hub was not pressed onto the axle shaft correctly and as such the whole wheel/tire/brake/rotor assembly was wobbling slightly causing the chirp as the rotor hit the brake pad. They are replacing the left rear axle assembly along with the rear diff fluid (needed to be done at 1,000 miles anyway
)As far as the trans he showed me where the fluid was leaking out the vent tube on top of the tranny. I let them know that the trans was hard to shift into 2nd when cold and they said they will be replacing the gear oil per a TSB, and making sure the level is correct. They said we will watch the vent for futher leakage. BTW I had them change the oil filter only and top off the oil. It only took 1 quart of oil with the filter change...pretty low consumption for 1300 miles!!
Great service for a really dumb issues...
Deysha