Need help diagnosing rear end noise

[Blk98Slobra]

Needs some help diagnosing this problem guys. A few months ago, a friend and I redid my pinion seal and also put on a ford racing diff cover along with MM diff bushings. In the process of installing everything back in, I knicked my outter halfshaft boot. Realized this after I drove it down the highway and fluid was all over wheel. No big deal, got another halfshaft (used) and threw it on there.

Last week, I noticed a new noise that started at around 55 mph. It sounds like bearing noise, but it’s only coming from the left rear. My thoughts are it possibly could be the halfshaft, seeing as i did buy it used and the seller acted fairly shady During the transaction (whole different story).

At this point, like i said earlier, could be the halfshaft or it could be a totally different problem. Should I buy another halfshaft? Or, just bite the bullet and take it to a reputable shop here in town? I will also add, car has had gear whine since I bought it from the original owner at 145k miles.

 

[nxhappy]

sounds like the rear end needs a rebuild. if it's not PERFECT it will whine again.

 

[Blk98Slobra]

sounds like the rear end needs a rebuild. if it's not PERFECT it will whine again.

I figured that would probably be the direction I’d have to go with. Any recommendations on what I should be buying now so that they can just install everything for me? Shops around here typically charge way more for the parts versus me sourcing them out.

 

[olympic]

You said the noise was coming from the left-rear, any chance it's a wheel bearing? Maybe jack the car up and wiggle the wheel to see if there is any play in the bearing.

Also, if your diff is now solid mounted with aluminum bushings you will get some added differential noise in the cabin that wasn't there before.

 

[Albatross]

I would also recommend checking the torque on the axle nuts. Those have been known to come loose. Torque spec for the axle nuts is 250 ft lbs.

 

[TerminatoRS]

You said the noise was coming from the left-rear, any chance it's a wheel bearing? Maybe jack the car up and wiggle the wheel to see if there is any play in the bearing.

Also, if your diff is now solid mounted with aluminum bushings you will get some added differential noise in the cabin that wasn't there before.

+1

I would also recommend checking the torque on the axle nuts. Those have been known to come loose. Torque spec for the axle nuts is 250 ft lbs.

+2 Especially considering you've replaced the half shaft, you've obviously removed this 36mm nut before. Also, the recommendation is getting a new nut instead of reinstalling the old one.

 

[Blk98Slobra]

+1



+2 Especially considering you've replaced the half shaft, you've obviously removed this 36mm nut before. Also, the recommendation is getting a new nut instead of reinstalling the old one.

Thanks for the replies guys. I did torque down the nut to 250 lbs, but I also reused the original nut. I did buy another one (updated Ford nut). I’m going to try and jack the car up tonight or tomorrow night and see if I can hear the noise. If it sounds like it’d coming from the area, I’ll replace the nut and see if that helps out.

 

[Blk98Slobra]

Just a quick update. Replaced the IRS castle nut with the new updated Ford nut and don’t hear the noise anymore! I’ll probably take it for another drive this week just to double check. Thanks for the advice guys.

 

[hotcobra03]

Why didn’t you replace your boot verse whole shaft?

 

[Blk98Slobra]

Why didn’t you replace your boot verse whole shaft?

I didn’t want to go through the trouble of pulling off both boots to get the messed up boot off. When I replaced the half shaft, I ended up damaging the inner boot too lol. I ended up buying boot replacements and was going to do the job so I could have an extra half shaft; but once I pulled one of the boots off, found more damage to my stock half shaft.