Why do we repack just the front wheel bearings?

[scottm]

I'm thinking about doing the fronts at 100k, but what's the point if the rears are "run to failure"? Plenty of 80s have run over 200k without any bearing maintenance, but is there a reason the 100 rears should not need maintenance? I see it's a ball bearing, used on other vehicles, perhaps uses the diff fluid to cool and lubricate?

 

[badlander]

I think the rear bearings get lubed full time by the oil in the differential. They don't use grease like the fronts.

 

[spressomon]

The rear axle bearings are not user serviceable. The diff lube does not lube the rear axle bearings; there is an axle seal located on the outer portion of the axle housing tubes that keeps the diff lube from the bearings. The rear axle bearings are a combination of sealed cartridge style bearings and greased open roller ball type bearings. Typically failure occurs when either the outer or inner seal fails and diff lube purges the grease from either or both bearings or contaminant enters past the outer seal and eventually contaminates one or both axle bearings. This semi-float axle is a completely different design compared to the full float 80-Series style rear axle/bearing assembly.

 

[LCHardriver_02]

Any idea as to why T went this route for the 100? $$?

 

[1loudLX]

dont let spresso see that comment...this thread will go on for ages! I had the beginning of the failure described, but addressed it while doing the lockers.

 

[spressomon]

Its a fine design/bearing system for the intended audience. Its just not the best system for those that do repeated water crossings and/or ned/want to be able to PM/replace axle bearings themselves. There is ZERO chance this could be an in-the-field fix.

Under the typical conditions the 100-Series' (IMO) targeted audience/buyer you're probably looking at a service life of around 200k miles (that would be about 3.25 target market owner's possession of this rig ).

 

[wildsmith]

I've pulled my rear hubs about every 6 months or so to check them for signs of failure. It's not a big job.

 

[scottm]

Can they be DIY serviced at all? Would I have to pull the entire axle housing out of the truck?

 

[spressomon]

You just have to remove the axles themselves which is the beauty of this design (similar to a Ford style cartridge hub assembly). But it goes downhill fast if you actually want to service or inspect the bearings. You can, as wildsmith stated above, remove the rear axles (make sure you have the rear e-locker engaged if so equipped!) to see if the axle housing seal has failed (then there would be diff fluid past this seal) and maybe how smooth the bearings feel. You can't, however, see the larger outer roller bearing without completely tearing the outer axle assembly down. For this you'd need, at the very minimum, a large tonnage press and the special SST bearing and collar press tools (any machinist could make these for you) and experience reassembling with the proper preload/spacing.

 

[wildsmith]

Inside the end of the axle tube

Back of the hub that fits on there

The area in green is just something I was pointing out in a different thread where there's not so much clamping force and they seem to go rusty and eventually let water in there. I know of at least one case of the rust that caused in the back of the hub causing complications for servicing the bearings when it came to replacing them. Like spressomon pointed out there's a limited amount you can check from this but it makes me feel better

 

[pman]

Its a fine design/bearing system for the intended audience. Its just not the best system for those that do repeated water crossings and/or ned/want to be able to PM/replace axle bearings themselves. There is ZERO chance this could be an in-the-field fix.

Under the typical conditions the 100-Series' (IMO) targeted audience/buyer you're probably looking at a service life of around 200k miles (that would be about 3.25 target market owner's possession of this rig ).

So the design is better/intended for for dry places?

What do you mean 3.25 target market owner's?

Any tips on how to make water crossings less likely to cause damage?

 

[Hank]

So the design is better/intended for for dry places?

What do you mean 3.25 target market owner's?

Any tips on how to make water crossings less likely to cause damage?

If avoidable don't go in water with hot/warm differentials. Make sure your vent is clear, avoid prolonged submersion.


What, you guys don't carry a shop press on the trail??

 

[spressomon]

So the design is better/intended for for dry places?

What do you mean 3.25 target market owner's?

Any tips on how to make water crossings less likely to cause damage?

Oh its just my little dig at the mall crawler/soccer Mom's that buy them and trade them in when they get to about 60,000 miles . So somewhere downstream, from a brand new 100-Series, the 3.25th (sorta like the average American has 2.2 kids ) owner might have to deal with the rear axles

Yeah...self admittedly I have a weird sense of humor! And my math isn't very good sometimes: Should be 3.33rd downstream owners

 

[OGBeno]

Yeah...self admittedly I have a weird sense of humor!

Understatement!

 

[NMuzj100]

Front Bearing Service Data Point - When Slee's guys serviced the front bearings on my 100 at ~156k they found that they had never been opened. They said they were in great shape and all the bearings could be reused. Slee told me that the OEM Toyota lube must be good stuff.

There might be a good argument for not doing them if they have never been opened before.

 

[scottm]

The front outer wheel bearings on the 100 are the same as the 80 front and rear outer. The inner bearing has a different part number. At 150k my 80 front bearings looked good, perhaps a hint of the inner bearing spinning in the hub, but might have been machining marks. I had new Timken bearings in hand from AutoZone, so I could return them if I didn't need them, and I replaced them just for the heck of it. At AutoZone when they look up your vehicle they get a Timken number to search for on the shelf, they're organized by Timken number. For my 80 they didn't show some bearings in stock, but they did find the bearings when they walked back and checked the shelf for the Timken numbers I gave them.

For my '03, from the Timken catalog:
- Front inner wheel seal: 710456
- Front inner wheel race: JLM506810
- Front inner wheel bearing: JLM506849A
- Front outer wheel bearing: Set47 (bearing and race)
- Rear wheel seal: 225874
- Rear wheel bearing: 510011

The seals and front inner bearing are Toyota specific, the rear bearings are used on Acura, everything else shows a variety of vehicles using that part, especially Set47, very common. I would get everything from cDan/Beno again, but might get the front bearings from AutoZone if I wanted to decide whether to replace or repack while doing the job.

 

[rmtannerjr]

I know this is an old thread but just wanted to give an idea of what the longevity can be for these bearings. I've been hearing a scrubbing noise as I cut my wheel and back out of the driveway which should put some side pressure on the rear bearings if i'm not mistaken. Now it's continuous driving down the road after a couple
of weeks. Haven't gotten it looked at but I'm fairly certain the drivers side rear is gone.

And it lasted just over 400,000 miles. I have been though some water lately too... Hmm

 

[Mxndrnks]

I know this is an old thread but just wanted to give an idea of what the longevity can be for these bearings. I've been hearing a scrubbing noise as I cut my wheel and back out of the driveway which should put some side pressure on the rear bearings if i'm not mistaken. Now it's continuous driving down the road after a couple
of weeks. Haven't gotten it looked at but I'm fairly certain the drivers side rear is gone.

And it lasted just over 400,000 miles. I have been though some water lately too... Hmm

you sure it isn't the dust shield? At that millage i would replace the bearings anyway... but the noise could also be the dust sheild...

 

[lexi4darin]

400k? That a typo?

If not, congrats!

 

[2000UZJ]

^ nope. He posted it in the high mileage thread. Pretty awesome if you ask me. I would check the dust shields as well. You said water, which means you have been offroad (obviously). Probably something trapped back there. I get gunk in there all the time. Take a pressure washer once everything has cooled down and spray the dust shield from the wheel side. You will be amazed at how much garbage gets blown out.