I see lots of posts on whining/howling from the rearend when people get work done on them, such as new gears. However, mine is compeltely stock. I haven't put in new gears or anything and it's howling.

It's proportional to vehicle speed. If I'm cruising, put it in neutral and rev the engine, the noise doesn't change tone. I can really hear it above 30 MPH. I couldn't tell where it was coming from while driving - from the front, back, side, so I put the back up on jackstands and still heard it, so it's not the front.

What i'm not sure of is if it's really coming from the tranny, getting transmitted through the driveshaft and sounding like it's from the rear end. From what I've read, it seems to be the U-joints. But the joints are stiff and I can't wiggle or otherwise move them. When I spin the tires, there is a screeching sound coming either from the front or back of the driveshaft - I can't tell, but is it possible that this screeching at very very low RPMs of the shaft turns to a howl at higher RPMs?

I recently had the car in to have the pinion seal replaced because it was leaking, so I don't know if the shop put it on crappy or what - but it was fine for a couple thousand miles. I've always had noise from rearend, but this is in addition to the noises I've always had. There seems to be enough fluid in the pumpkin, so I don't think it is that. When I took the plug out, oil leaked out so I know there's some in there.

So... Is my rear-end about to go? Should I bother replacing the u-joints or just take it into the shop (I still have an extended warranty on it)? Like I said, it's a stock rearend so it's not like the backlash is off or something. Ideas??

Thanks in advance!

Jim

 

Sounds like pinion bearings...When you replace the pinion seal you have to be very careful when reinstalling the pinion nut to the same thread position and tension. A lot of shops just crank back down on the pinion nut not having paid attention to its thread position before removal. Too tight and you'll make the pinion bearings howl...Been there, done that... It makes the whole rear feel "tight" and will destroy the pinion bearings...

--Alan

 

^ ^ ^ I'm with Alan .

Although I had a carrier bearing go in my 2.73 diff ... same sound/symptoms though.

 

its probably the crush sleeve, when you put the pinion flange back on and don't torque it to the right setting, it will cause the gear to be able to move up and down alittle giving you that grinding noise. It could also be the bearings like they said, but that would be because of the crush sleeve being over or under tightened. have the backlash and the gear pattern checked. you'll probably have to have the rear end rebuilt.

 

Thanks for the replies guys.

What should the nut be torqued to, so I can tell the guys at the shop?

Also, how do I know if the rear end needs to be rebuilt? Just curious because if the shop says no way, I want to be able to convince them they're wrong.

Thanks again,

Jim

 

It has to be in the same "position" that it was in when it was removed..Some will take paint and mark the nut and threads to get it as close as possible. Others count threads, etc..Sounds like this shop just overtightened it, which is very common...I would ask them the procedure they followed to do the job and see what they say...don't lead on that you know anything and then hit them with this info and see what they say...Good luck...

--Alan

 

Thos SOBs! The pinion seal was replaced on 4/13/06. They have a 3 month/9,000 mile guarantee on it, which I'm past.

I asked what procedure, and since they're a Chrysler dealer (I bought my car used), they would only refer to whatever their Chilton manual says. If it was Chrysler, they could go through it step by step.

And even if it was under the 3 months, all they would guaranee would be the seal, not the bearings. And if I bring it in for differential noise, they'll probably bring it to their sister shop, a Pontiac dealer - which is better, but not good.

My deductible is $200. Should I replace the bearings myself? Should I bring it in so they can look inside the diff better than I could?

If the pinion seal has already been carelessly removed and reinstalled, how do I count the number of threads now???

 

If they won't stand behind their work and you don't want to persue it further, then I'd find another shop that specializes in rears, trans', etc and have them do it..I don't mess with rear set ups...You may want to take this opportunity to upgrade components, etc, but I certainly won't go back to that dealer...

Find a place you trust to take everything apart and see whats going on in there..

--Alan

 

IIRC, the "book" spec says 20 inch*lbs of drag on the pinion when tightening the pinion nut. It's enough so that the pinion won't spin free if you give it a quick spin, but you shouldn't have to put a breaker bar on it to turn it either.

 

Thanks everyone for your input. Much appreciated and helpful!

Jim

 

Yep, it was the pinion bearings and side bearing. Thankfully the Chrysler dealership where I bought it (and thus have a warranty from) took the car to their sister Pontiac dealership to be worked on.

Needless to day, not only is the whine/howl gone, there are no noises whatsoever. It's quieter than it's ever been - at least for as long as I can remember. In fact, the car feels more solid when the transmission shifts and when I go in and out of Drive or Reverse.

Thanks again for all your help guys, my baby is safe and sound!

Jim

 

Doh! naughty firefox...