I think I have a bad rear wheel bearing. I have a Haynes manual, which doesn't seem to call out the rear from the front, and seems to indicate that it's just a couple of bolts behind the wheel hub. Is it really that easy? Being on the rear, is there an issue with getting the brakes out of the way (I haven't done the rear brakes, so I don't know how easy/hard this is)?

 

The "rear wheel bearing" is called an axle shaft bearing in the FSM. This part is behind the axle shaft seal and is a pressed in part. It does not require removing the brakes, just the axle shafts. You'll need to take off the diff cover, remove the center pin, axle shaft c-clips, slide the axle shafts out, pry out the axle shaft seal, and use a bearing puller to remove the axle shaft bearing. The new one needs to be hammered in, but you'll need a tool the exact size of the bearing so you don't damage it.

Just out of curiosity, what makes you think that particular bearing is bad?

 

Well, that became a more interesting question last night.... I thought is was in the rear because the howling sound seemed to be coming from the rear, but it's hard to tell. So last night I jacked it up and spun the rear wheels by hand. Nothing seemed out of order. I didn't have time to try the front, so I'll do that this morning. If I can't figure it out, I'll probably have to take it to a shop to diagnose. But my only realistic guess at this howling noise is a bad bearing. The pitch of the sound is exactly proportional to speed, doesn't change on different road surfaces, doesn't change when it shifts gears, when I brake or turn. But there's no noticeable slop in the suspension yet.

Time to go jack it up again. Back in 10.

 

Looks like it might be the front driver's side. When I spin the tire by hand, I hear bit of noise. The front right felt just fine. But since I can only spin a tire so fast by hand, the noise I hear in the front left is pretty faint. But it is sort of like a quiet version of cards in bicycle spokes. It's a very rapid, faint almost clicking "brrrrrrrr" type of noise. No play in the suspension when I try to lift the tire.

Is this what I would expect from a bad bearing?

 

Well now I'm stumped. I had my wife drive it and I rode next to it on my bike. Left side and right side front and back, at about 20mph. I was completely unable to tell where the noise was coming from. It almost sounded like it was coming from directly under the middle of the truck. It's also louder inside than it is outside the truck. I'm almost thinking it's coming from the drive shaft or somewhere near there. Of course, based on the description above of replacing the rear bearing, that may actually be the problem.

 

Does it make the noise under acceleration, or coasting, or does it not matter which? I had my pinion nut come loose which took all the preload off the pinion bearing and whenever I would coast in gear or engine brake, it would make a whirring noise. Just another suggestion if this sounds anything like your problem.

If you haven't already, you should download the '01 Dakota FSM available somewhere in the Gen 2 FAQs. It has a whole section devoted to the rear axle and diagnosing noises and repairing them.

 

Thanks for that info. I'll look that up.

It makes the noise consistently, no matter what.

I took it to Carmax for their free appriasal (I actually do plan on selling it), and they said it was the diff. Since they probably don't realize the rear bearing is in there, I'm guessing that may be the problem. I think my next step is to take it to a real shop, possibly even a stealership, and pay them the $100 to tell me difinitevely. Then I decide whether I want to do it myself or not. I can probably borrow a bearing puller from Advance Auto, and fab up a piece of wood the right size to hammer in a new bearing if that's the only problem.

 

I also think my Dakota has a rear bearing problem too.

I get a constant whine that increases in frequency (pitch) with vehicle speed (barely noticeable at slow speed) but progresses.

It does not change pitch at a specific speed except when you let of the gas then it briefly quiets or briefly when going over some bumps but returns to the speed dependent pitch.

If I put the trans in neutral while rolling at speed it does not change tone so I think this means the rear differential is ok. I checked the rear differential fluid and it seems to smell ok and fairly close to the fill hole.

Thoughts?

 

my whole rear was shot i had most of my noise from my pinion bearing when i ripped everything apart i noticed the pinion shaft was not even touching my ring gear(well barely) making my noise right there.