Rear End Noise - something new?

[GVW299]

2011 with 140k miles. Have been noticing a new rear end noise last few months. Took it to a Ford Tech and he had trouble replicating - he said would drive this truck across country any day so $180 inspection fee and no diagnosis.

To me, it seems to be getting louder the last 2 months. The noise is on acceleration but disappears on coast so I thought a load side pinion bearing but maybe not loud enough. I opened the diff intending on replacing the carrier and pinion bearings this weekend. Diff fluid was pristine, no metal, nothing untoward on the magnet. Ring gear backlash is 12 thou (spec is 8-12 thou). Ring gear, spider and side gears look great. Wear pattern in the yellow goo looks fine. Everything rotates fine with no untoward noises. Didn't take out the carrier yet and backtracking on replacing the 4 diff bearings because maybe that is not the problem?

When I took the axles out, I noticed the plastic coating on the ABS tone rings are worn on both axles. Now I am thinking the axle bearings were worn and the noise was coming from the tone rings contacting the ABS sensor posts intermittently. No rub marks on the sensor posts that I can see but they are really just getting through the plastic so far.



ABS sensor post is at 9 o'clock. It is 18mm from the hub and with the axle installed is only 1 or 2mm from the tone ring.



I replaced the axle bearings and seals and I can button it back up and hope the noise goes away or,
while it is open I can pry off the tone rings and press new ones on (~$70 each OEM),
or if the noise is still there, will do the diff bearings next weekend.

Has anyone come across this tone ring wear and how likely to be the problem?

 

[mprice1234]

Good write up! Sorry but I have nothing to add to help you other than good luck running down the noise.

 

[MTF]

You didn't say what type of noise, so I'll just post what happened to me, hopefully it might help.
I have a video of the noise from the rearend when I had to replace every bearing in the pumpkin including the pinion bearing.
The outer axle bearings were fine.
Luckly warranty covered the cost to completely rebuild the rear.
I had them put the Magtech cover on and use Mobil 1 oil.

 

[fordfreek]

Based on your description of the noise, I'd say your inner pinion bearing is bad. If you still have the axles out, pop out the differential and spin the pinion by hand. Should be able to feel and/or hear it.

 

[GVW299]

You didn't say what type of noise

Thanks for the input as this seems like a rare one. Can't even find a youtube about replacing this type of tone ring on an F150.

It is like metal on metal like an angle grinder on steel but very subtle, maybe like bad pads rubbing on a rotor. Nothing like a bag of bolts in a washer. Pretty constant on load then nothing on coast. With worn bearings, makes sense under load that the axle pushes toward the rear and contacts the sensor post then on coast, the axle would push forward. The OEM axle bearings were Torrington and the new ones I got from Ford are Koyo. Motorcraft seals. Going to put some sort of sealant on the tone rings then put it back together. No codes in the system but they would not have been far away if this kept rubbing.

 

[MTF]

Are you sure it's from the rear?
I mean, I'm sure you can tell the difference between the noise coming from the front or the rear.
But just mentioning it.
Because, if it only happens when accelerating... it could be the IWE.
You may just have a small enough vacuum leak that the IWE is just starting to engage.

 

[GVW299]

Didn't get a chance to get back under until this evening. I got to the bottom of it finally. New rear wheel bearings and the noise was still there - of course. I could swear I could hear it in the rear axle but it was in the front. I ruled out the IWEs a few weeks ago but replaced the solenoid and valve anyway.



The driver's side O2 Sensor and Catalyst Monitor Sensor connectors and cables were rubbing on the front drive shaft between the Transfer Case and the Front Diff next to the transmission. One of the connectors was rubbing at that silver band lower down and part of the sheath was rubbing higher up. The thicker part of the cable is supposed to be secured higher up with a Christmas tree plug but it was out.

I had checked the rear drive shaft for rubbing but was fixated on it being at the back and forward of the transfer case is out of sight out of mind when you are not on a lift.

Second picture is with the cables where they are supposed to be with the help of some zip ties.


I appreciate the suggestions. Glad I found this as I was about to order new hub and bearing assemblies for the front so saves me some $$. New idler pullies, a tensioner and serpentine belt arrived today but will probably just put them on anyway.

 

[Space Ghost]

Didn't get a chance to get back under until this evening. I got to the bottom of it finally. New rear wheel bearings and the noise was still there - of course. I could swear I could hear it in the rear axle but it was in the front. I ruled out the IWEs a few weeks ago but replaced the solenoid and valve anyway.

View attachment 425609

The driver's side O2 Sensor and Catalyst Monitor Sensor connectors and cables were rubbing on the front drive shaft between the Transfer Case and the Front Diff next to the transmission. One of the connectors was rubbing at that silver band lower down and part of the sheath was rubbing higher up. The thicker part of the cable is supposed to be secured higher up with a Christmas tree plug but it was out.

I had checked the rear drive shaft for rubbing but was fixated on it being at the back and forward of the transfer case is out of sight out of mind when you are not on a lift.

Second picture is with the cables where they are supposed to be with the help of some zip ties.

View attachment 425615
I appreciate the suggestions. Glad I found this as I was about to order new hub and bearing assemblies for the front so saves me some $$. New idler pullies, a tensioner and serpentine belt arrived today but will probably just put them on anyway.

Its always the most random shit lol, glad you fixed it.

Reminds me of loud meta banging i heard when driving my lightning that got worse with speed. Sounded like a dump truck gate slamming. Checked driveshaft, wheels, brakes, axle, running out of ideas and then i check the prking brake.

Guess it had enough and separated and was the cause of the noise.