2nd Gen Non-Engine/Transmission 2WD Wheel Bearing Questions

[charlessmith]

These questions are about my '96 Ram 3500 2WD, with a Dana 80 LSD rear axle. It just turned 200,000 miles.

I've got a noise that I've heard for the last 30,000 miles or so. It varies with road speed, and does not change under light throttle or trailing throttle. It's been so faint that it's almost unnoticable. When I first heard it, my thought was 'wheel bearing'. But back (drum) wheel bearing noises generally go away when you are on the brakes, and this doesn't. Front wheel bearing noises generally come and go when you turn around a sharp corner, and this doesn't. I can't feel any hub that's noticably warmer than another.

My imagination is probably working overtime, but it seems a tiny bit louder the last few thousand miles. It's most noticable rolling at 25 - 35 MPH, it's just a faint rrr rrr rrr noise, maybe at about wheel revolution speed. I've kept driving it with the theory that it'll get worse and then I'll be able to identify the problem! But since I'm heading for Alaska in a month or so, the last thing I want is a failure on the road.

So my questions are -

1. if it's not a wheel bearing, what can it be?

2. This has the one piece extended (for dually wheels) front hub / brake disk. Is there anything unusual about changing front wheel bearings?

3. What's involved in changing rear wheel bearings on the Dana 80 axle?

4. What's the recommended brand and source for wheel bearings? My main interest is which ones hold up the longest.

Thanks for thoughts and suggestions.

 

[Vaughn MacKenzie]

Have you changed your rear axle fluid lately? Drop the pan and take a look. . . if a bearing is deteriorating there will be metallic flakes in the lube. . . a lot of them.

If all is clean then service the front wheel bearings (pretty easy on '99 and older trucks). Just pull the caliper and remove the rotor and clean/repack the wheel bearings. If it hasn't been done yet 200k is a little overdue

 

[GAmes]

As Vaughn said, 200k is a long time for no service. It may be overkill but I repack my front bearings every 50k and change diff oil at the same interval. I have never pulled a hub on the rearend, even the rear brakes shoes are original. I do tow a lot too, about 70% of my miles have had a trailer of some type hooked up.



I would repack the front bearings and then drive it to see if they are the source of the noise, then change diff oil. If you do both at the same time and the noise goes away you won't know what caused it. I use Timbren bearings in all my vehicles when change out is needed.

 

[charlessmith]

Well, good news and so-so news.

The good news is that it was a front outer wheel bearing.

The so-so news is that while replacing and repacking the front wheel bearings, it was apparent that both lower ball joints were loose.

So, that got added to the list. I got Moog upper and lower ball joints, and took everything apart. The uppers fit fine. The new lowers are 0. 010" smaller than the ones that came out. This is a '96 2WD 3500 diesel with independent suspension.

The OD of the old wheel bearings where they press into the A frames is 1. 996" - 1. 998". The new Moog parts supposedly for this '96 are 1. 981" - 1. 985" diameter. They not only do not press into the A frames, they are a loose fit.

The auto parts guy lists a different part # for a '97 3500 2WD diesel, and after calling to ask his warehouse to mike them, they are the correct size - 1. 998".

So I'll have two '97 lower ball joints in the morning. And assuming all other dimensions are the same correct sizes, I'll be able to put it back together. The part # on the '97s is K7269.

Has anybody else run into this? So close and yet 0. 010" difference between years seems really strange ... ???

 

[GAmes]

Has anybody else run into this? So close and yet 0. 010" difference between years seems really strange ... ???

It is common occurance for parts places to have the wrong listing.