Constant rear axle whining/groaning noise from rear axle 2013 Mustang 5.0 track pack

[TrackpkCoyote13]

A little info and history on my 2013 5.0 MT82 track pack. It has the 3.73 rear gears with the Torsen. It also has the aluminum diff cover with the fins and drain and filler holes. I have 33,000 miles and the car is stock except for the mufflers and tune. Original suspension, driveshaft and rear axle. I did have a leak around 10k miles and the dealer drained the fluid and replaced the seal. Haven't had a leak since. My car has not seen any track or drag strip use but has been driven for fun mostly around the local area. I would describe my driving as normal, but I do some hard launches and acceleration occasionally. I don't do much freeway driving other than picking up my son who lives a hour away, when the weather is nice. Because the noise started worsening, I recently changed the rear axle fluid myself and used 75w-140 fluid with friction modifier.

Also, I did not see another thread on this that was similar, so hopefully this is ok.

The noise I'm certain is from the rear axle and the recent fluid change seemed to quiet it down temporarily IMO, but it's still getting louder with time. The noise is constant and noticeable as soon as I start accelerating and gets louder the faster I go. It sounds like a whining/howling sound, no grinding or anything that would send a red flag. When slowing down and I'm going about 5-10 mph, the noise sounds a little wobbly and groaning. I'm not driving the car much currently other than the occasional drive to keep it fresh.

My car is not winter driven and my plan is to go to Brenspeed for a rebuild and upgrade in the Spring. However, I'm worried about further damage and whether it might not make it there (about 200-250 miles away) by breaking down, or worse by it failing and getting into an accident. I don't want to take it to the Ford dealer since I want to upgrade and don't want to waste money since I'm upgrading. I appreciate any help on here. Thanks.

 

[GriffX]

I had a similar noise and the failure was the big pinion bearing. I don't think there is a big risk of getting further damage. I would drive the 200 mi with it and expect that the noise will increase with differential heat up.

 

[TrackpkCoyote13]

I had a similar noise and the failure was the big pinion bearing. I don't think there is a big risk of getting further damage. I would drive the 200 mi with it and expect that the noise will increase with differential heat up.

Thanks. I do drive it occasionally, even thru the winter when salt is not out so it doesn't sit too long and get issues I'm sure you are familiar with. I'll probably put 300-500 miles by the time I get it fixed, and it's pretty loud to the point I can barely hear the exhaust and I have GT500 mufflers. Hopefully it holds up.

 

[GriffX]

Do you have access to a lift? If so, you can check if the pinion nut came lose after they changed the pinion seal.

 

[TrackpkCoyote13]

Do you have access to a lift? If so, you can check if the pinion nut came lose after they changed the pinion seal.

I don't but I do have a good set of $220 Race Ramps I bought 10 years ago. I'll try to take a look. Any idea specifically I should look for?

 

[GriffX]

The problem, on race ramps you cannot turn the driveshaft with your hand and therefore not take out the driveshaft bolts. The pinion nut is below the rear driveshaft joint to the diff.

 

[86GT351]

The problem, on race ramps you cannot turn the driveshaft with your hand and therefore not take out the driveshaft bolts. The pinion nut is below the rear driveshaft joint to the diff.

Correct. All though the race ramps are a good idea, it won't work.