F350 DRW Brakes and rotors... should I replace bearings while I am at it?

Dadnatron · Nov 16, 2016

2006 F350 6.0 4x4 DRW (new to me) - about 150K miles

I am going to change out brakes and rotors this weekend.

Since I am going to be tearing everything out for rotors, it would be just a few more minutes to completely replace the wheel bearings. I don't know whether they are good or bad. Again, this truck is new to me.

Basically, since I will be removing and repacking the old bearings... I began thinking that perhaps I would simply completely replace bearings and seals.

I know the brakes are bad. I haven't taken the time (yet) to check the bearings, but since, they are relatively inexpensive given already being torn down, I am leaning towards complete replacement.

What do you think the utility of bearing replacement would be?

Am I missing anything? Am I being unreasonable in my thoughts? I haven't changed a wheel bearing in about 20yrs, but I don't know that they would be that much different now compared to before.

Billrog · Nov 16, 2016

My thought is if it's not broke don't fix it but then I'm not a mechanic either.

dieselcrawler · Nov 16, 2016

Double post

dieselcrawler · Nov 16, 2016

I am a mechanic, and have turned alot of wrenches on these trucks.

Repace the seal if you want but if its not leaking, I wouldnt bother. Bearings are lubed by diff oil, not grease. Check them by pulling the axle and spin the hub before removing bearing lock nut. If its smooth and no play, no worries.

Unless it looks like this... This is bad. Noticeable rumble when driving, rear inner bearing on my dually.

confused8122 · Nov 16, 2016

2wd or 4wd? Front brakes or rear brakes?

If 2wd and front brakes, then it's up to you and cost. But do the seals and repack bearings. If 4wd, don't touch the bearing unless it's bad(loose, noisy)
If rear brakes, inspect and replace if necessary, and replace the seal. (it's not ever going to be more accessible)
Dieselcrawler's advice is for rear brakes, and other than I would replace the seal, I agree.

Dadnatron · Nov 16, 2016

dieselcrawler said:
Bearings are lubed by diff oil, not grease.

Diesel... I understand the bearings are oil, however, everyone I've seen (on YouTube... and I know it isn't the ultimate source.) packs the bearings with wheel grease. I know that upon removing the axle, you lose a bit of oil. I can top that off in the diff case when I'm through.

But, do you just install the bearings 'dry' relying on the oil? I've never seen a wheel bearing installed that wasn't grease-packed. But then again, this isn't what I do on a daily basis.

Sawyer Rob · Nov 17, 2016

I ALWAYS pack the rear bearings when installing them.

It keeps them alive until plenty of oil gets to them and the grease just washes away in time anyway, so no big deal...

SR

ovrszd · Nov 17, 2016

confused8122 said:
2wd or 4wd? Front brakes or rear brakes?

If 2wd and front brakes, then it's up to you and cost. But do the seals and repack bearings. If 4wd, don't touch the bearing unless it's bad(loose, noisy)
If rear brakes, inspect and replace if necessary, and replace the seal. (it's not ever going to be more accessible)
Dieselcrawler's advice is for rear brakes, and other than I would replace the seal, I agree.

I'm "confused" right along with you. Not sure which we are talking about either.

Billrog · Nov 17, 2016

Unless the rear seal is leaking or the bearings (which I doubt) need replacing I would leave it be. Why mess with something that works. I've replaced a no. of seals over the years on my pick-ups and dump trucks but only after a lot more than 150k and they were leaking. Have never had to replace a bearing yet in a floating axle.

dieselcrawler · Nov 17, 2016

I wet new/dry bearings with a bit of diff lube before putting the hub on the spindle. When I'm done, top off the diff, and jack up the other side to let oil drain into the 'dry' hub, or park the truck on a sidehill for a while... Anything to get the oil to flow to the hub.

Never heard of packing a oil lubed hub with grease. I guess it would work... But I dont like the idea of contaminated diff oil, even if both are lube.

As pointed out earlier, I am speaking of rear full floater axles, that pertain to the OP's ford dually.

Front bearings are unit bearings/hub assembly's. Easy to replace... Costly. Wait till they go bad.

Stimw · Nov 17, 2016

You are there, remove them, inspect them (there are no secrets good VS bad bearings/races), replace the seals!
Also Change the rear axle oil, then top off.
You don't need to "repack" them because they weren't packed. A light coat of grease will hold until the oil circulates.
Short cuts will come back to bite you!

nickmags · Nov 18, 2016

As has been mentioned, "If it ain't broke, don't fix it" Inspect, sure.

3930dave · Nov 18, 2016

One more tip for that rear axle OP, as I don't think it's been mentioned....

Make sure to check that the axle vent line is clear. Sometimes people (even shops) change the seals to cure a leak, only to have it come back. Often the real problem in those cases is that the vent line is blocked. It doesn't take much dirt to block that small vent fitting hole, which can pressurize the diff once it heats up.

Rgds, D.

Dadnatron · Nov 18, 2016

I appreciate your thoughts.

I will check everything while I'm working on the brakes, but as has been often stated, I'll leave things alone until they are broke or bad, if they aren't showing issues.

BTW... I was talking about both front and back.

After checking on the hub assembly costs, I will just wait until/if they go bad. For Rears... I'll pull and check them out.

Thanks for the help, knowledge, and opinions.

QRTRHRS · Nov 22, 2016

At only 150k, unless this truck shows signs of abuse or leaking seals, I would not be pulling axles. If you do though, like mentioned, change the lube and use a synthetic. Make sure you raise and lower each side to drain the axle tubes. Is there a rear axle drain plug? Likely not so you will want to have a tube of silicon on hand to seal the cover.

Copperhead · Nov 24, 2016

Not sure why anyone would mess with their axle bearings. I typically haven't even checked or changed out drive axle bearings on my commercial trucks well over 1 million miles. Have never had to do bearings in a 3/4 ton in my lifetime, and I owned my first pickup in 1970. Seals a few times, yeah. Bearings, never. In almost 5 million miles of commercial driving, not one axle bearing replaced and two of my commercial trucks racked up over 1 million miles and I currently have 622,000 miles on my present one. Front axle hubs and bearings from time to time on some others, of course. Unlike Tim Allen's method which is..."if it aint broke, you can probably still fix it"... I prefer to actually not mess with something like bearings until it needs it. Axle gear lubes we have today are light years ahead of what was available decades ago.

QRTRHRS · Nov 25, 2016

Copperhead said:
Not sure why anyone would mess with their axle bearings. I typically haven't even checked or changed out drive axle bearings on my commercial trucks well over 1 million miles. Have never had to do bearings in a 3/4 ton in my lifetime, and I owned my first pickup in 1970. Seals a few times, yeah. Bearings, never. In almost 5 million miles of commercial driving, not one axle bearing replaced and two of my commercial trucks racked up over 1 million miles and I currently have 622,000 miles on my present one. Front axle hubs and bearings from time to time on some others, of course. Unlike Tim Allen's method which is..."if it aint broke, you can probably still fix it"... I prefer to actually not mess with something like bearings until it needs it. Axle gear lubes we have today are light years ahead of what was available decades ago.

Once upon a time I saw bearings like in the photo posted by dieselcrawer on a Mack Cruisliner with 200k on it. Hard to blame the 300 Mack with a five speed for too much grunt. Perhaps it was coming out of Canada with a load of white cedar after the sap came up.... But then 85-90k gross combinations will do that on trucks of that vintage.

confused8122 · Nov 25, 2016

QRTRHRS said:
At only 150k, unless this truck shows signs of abuse or leaking seals, I would not be pulling axles. If you do though, like mentioned, change the lube and use a synthetic. Make sure you raise and lower each side to drain the axle tubes. Is there a rear axle drain plug? Likely not so you will want to have a tube of silicon on hand to seal the cover.

Some years of the fords, rear rotors are captive. You have to pull the axle and hub to change the rotor.