Wow, that title is open to suggestion isn't it; but seriously, I've got a problem...

I have 2001 Dodge Ram 1500 2WD 5.2L Sport Club Cab with about 80k. Back around Thanksgiving I noticed a “whining” noise that seemed to be coming from the rear of the truck. I only heard it at highway speed and couldn't be sure the noise was from the rear. I immediately started to freak because I’ve heard these trucks have inherent tranny issues. So, I took the truck to a local mechanic. He heard the noise when driving the vehicle, but once he put it in the air…no noise. He checked everything obvious that didn’t require taking things apart (at least he said he did and I have no reason to believe otherwise as he comes highly recommended) and could not find anything. He didn’t want to guess, didn’t charge me for his time, and said we’ll need to let it get worse/ louder and try again.

Now it’s worse.

Like I said, the noise is a “whine” similar to the sound some vehicles make in reverse, can’t really be heard until 20MPH (use to be highway, then start at 30MPH, so it’s definitely getting worse) and changes pitch with speed. Talked to tranny guy and he doesn’t think it’s the transmission since there are no slips, pops, hesitation, can only be heard under load, and fluid level is good and clean. Fluid, filter, flush have been done twice in 80k. Most of the research I’ve done online points to the pinion bearings. However, the noise does not go away when you let off the gas at speed. It is present throughout the speed range and as I said does change pitch according to speed.

So, what do I do? I don’t want to drive it and risk having to rebuild a rear end if one of the pinion bearings go, but don’t like guess work either. Should I just bite the bullet and pay $500~ to get the bearings replaced and see what happens?

Thoughts, advice, and opinions…Thanks!

 

Your title is full of WIN!

As for the whine, it definitely does sound somewhat like a gear issue, but just to stick with the KISS method (keep it simple stupid) how old are your tires? I know I have some regular street tires that are pretty worn down that will whine like a spoiled rich brat when I'm going over 30mph. Its a shot in the dark, but its a free one. To me, if it was a gear problem especially with a bearing you would hear more than just a whine. More of a metal on metal clanking or grinding.

 

Failing bearings will be whiners as well. Have a look at the diff, are you losing fluid at the front pinion seal? What does the fluid level in the diff look like? Is it just low??

 

I thought about the tires too. However, I worked in the tire business when I was younger and it just doesn't sound like any tire noise I've ever heard. Seems more mechanical. They are probably 3yrs old, but still have decent tread and aren't cupped. It also doesn't seem like the noise would progress as it has, but who knows. Tires can do some weird things.

There are no obvious leaks around the diff. and if anything its to full. I think its supposed to be about a 1/4 inch below the fill plug, but when I loosened the plug fluid started to come out. I had a seal replaced last year and I guess they overfilled.

I was going to remove the cover and look for any metal or obvious damage, but I'm not sure you would see the beginnings of penion failure. I consider myself a pretty good "Home Mechanic", but I'm not sure I want to get into taking apart a diff; especially if I expect to drive it again anytime soon.

Wait a minute...how do you overfill the diff?

 

I had this happen to me this last summer. I changed out the diff fluid and put the limited slip additive in and the whine went away. Its kind of a shot in the dark but i would say if the whine doesnt go away after doing that its a pretty good sign that its time for new bearings. They really are not hard to replace pinion bearings but if your not 100% sure you can do it after you research how to do it i would have a shop do it.
Thats just my .02

 

Well, he had a seal replaced in the not so distant past...... If that was the pinion seal, my guess would be that's where your whine is coming from.

 

99% sure that either your inner or outer pinion bearing is worn. had this happen in my 98 ram 1500 5.2l 2x4 so i put a junkyard axle in it and its doin it again now. pretty easy to replce them if you have acess to a press. just dont break the bolt that holds the carrier pin in place or your f***ed!