wheel bearings

[razorback]

Dear Sunrader Owners.

I just bought a 86 sunrader with a full floating 6 lug axle. My mechanic mentioned ALL the wheel bearings need to be greased and repacked as the rig as 89,000 miles on it.

Is there truth to this? No leaks.

Thanks.

Jamie

new owner

[Maineah]

I know this will start an argument but the rear bearings are lubed by the differential as they are on any full floating rear. The only time you would need to grease them would be if the hub and bearings had been removed for brake/seal work. Gear oil is an excellent wheel bearing lube just ask any long haul trucker with a million or more miles on their rigs. Generally it’s a good ideal to do the fronts every time you do the brakes. If you are concerned about rear brake lining there are inspection plugs on the outer edge of the backing plates that will allow you to see the edge of the lining.

[razorback]

I know this will start an argument but the rear bearings are lubed by the differential as they are on any full floating rear. The only time you would need to grease them would be if the hub and bearings had been removed for brake/seal work. Gear oil is an excellent wheel bearing lube just ask any long haul trucker with a million or more miles on their rigs. Generally it's a good ideal to do the fronts every time you do the brakes. If you are concerned about rear brake lining there are inspection plugs on the outer edge of the backing plates that will allow you to see the edge of the lining.

Thanks for the insight. And sorry for the repeated post... it was my internet connection.

So in your opinion - to repack, and re grease the wheel bearings is overkill.

The wheel gaskets show no sign of leaks or cracks.

I have no leaks, and no noise issues.

Just want to be road ready.

Jamie

[fsprandy]

The rear bearings in the Toyota full floater are not lubed by the differential oil. They must be repacked with grease periodically.

[Maineah]

The rear bearings in the Toyota full floater are not lubed by the differential oil. They must be repacked with grease periodically.

No one in their right mind would build a full floating duel wheel rear with bearings that require short term maintenance the whole ideal behind a heavy duty rear is to run them hundreds of thousands of miles. There is no seal inside of the axle tube oil is going to run into the bearings like it or not. Gear oil is a far better lube for bearings then grease it stays put. The pinion bearings and the carrier bearings run forever in gear oil. Think about this every other full floating rear has gear oil lubed bearings no exceptions why would Toyota reinvent the wheel?

[ralph]

No one in their right mind would build a full floating duel wheel rear with bearings that require short term maintenance the whole ideal behind a heavy duty rear is to run them hundreds of thousands of miles. There is no seal inside of the axle tube oil is going to run into the bearings like it or not. Gear oil is a far better lube for bearings then grease it stays put. The pinion bearings and the carrier bearings run forever in gear oil. Think about this every other full floating rear has gear oil lubed bearings no exceptions why would Toyota reinvent the wheel?

i don't know why but they did it on my 1986 odyessey

[jim]

i don't know why but they did it on my 1986 odyessey

Whether you think its right or not it is true, there is a seal at the end of axle tube to stop oil from entering hub past axle shaft. Bearings are to

be greased,,,how do I know,, because I have had my 1990 22ft winnebego apart and done it,,,also I am a 20 year Toyota tech.

Jim

[Derek up North]

Sorry to drag this out of the 'grave', but I like seeing things in print.

I've read/heard that the Toyota 1-Tonne axle (and also the Nissan) need the rear bearings repacked. I've never read it other than by 'some guy on the internet', and nice as 'guys on the internet' are, I always prefer to verify.

I started my search for 'truth' by looking in my copies of Chilton for both Toyota and Nissan. They both say exactly the same thing:-

"Only the front wheel bearings require periodic service ..."

Before anyone points out that this doesn't apply to 1-Tonne vehicles, in the Chilton Toyota description of the correct procedure for the front bearings, they list different values for adjusting the front hubs for single and dual rear wheel vehicles (i.e. they do acknowledge the 1-Tonne).

Next to the Owner's Manual in the glove box. Here it just say "Repack wheel bearing grease." So not really clear if it's front only or all.

So, does anyone have access to a Factory Service Manual that covers the 1-Tonne rear axle? The only one I've found online is for the Pathfinder, which doesn't cover the 1-Tonne.

It seems to me that Chilton got their 'front bearings only' information from somewhere and that if countless owners had followed these instructions since the mid '80s without a rash of axle failures, then it must be good info.

Feel free to prove me wrong. I don't mind learning. But I do mind repacking rear bearings if it's not required!

[Derek up North]

Did some more digging and came up with the 93 FSM. The Service schedule specifically (and ONLY) mentions repacking the front wheel bearings.

http://personal.utulsa.edu/~nathan-buchanan/93fsm/maintenance/1maintena.pdf

http://personal.utulsa.edu/~nathan-buchanan/93fsm/maintenance/2maint.pdf

So it seems to me that if the rear bearings not being repacked lead to premature failure, there would have been a TSB issued. I've never heard of one.

[fsprandy]

Derek,

FWIW the owners manual that came with my '86 says to repack the wheel bearings every 40,000 miles or 4 years, whichever comes first. They do not specify which wheel bearings.

fspr

Did some more digging and came up with the 93 FSM. The Service schedule specifically (and ONLY) mentions repacking the front wheel bearings.

http://personal.utul...e/1maintena.pdf

http://personal.utul...ance/2maint.pdf

So it seems to me that if the rear bearings not being repacked lead to premature failure, there would have been a TSB issued. I've never heard of one.

[powdrhound]

My 1986 Toyota Repair Manual has a nice section on the "Rear Axle Shaft And Axle Hub (Double Tire)". [if I can get my scanner working, I will add it to the Manuals section.]

It also does not specify any Rear Bearing schedule.

On the other hand, the diagram definitely show an inboard Oil Seal. That would separate the bearings from any differential fluid. The re-assembly section also has good bearing repacking instructions.

Since you have to pull the rear hub to service the rear brake shoes , the hub/bearing assembly will be sitting on the floor in front of you. This is the obvious time to repack the bearings and replace the inner oil seal and the axle paper gasket

So, the service interval for the rear bearings will be whenever the rear brake shoes are replaced/serviced.

Now to find those inspection plugs...

John

[DanAatTheCape]

No one in their right mind would build a full floating duel wheel rear with bearings that require short term maintenance the whole ideal behind a heavy duty rear is to run them hundreds of thousands of miles. There is no seal inside of the axle tube oil is going to run into the bearings like it or not. Gear oil is a far better lube for bearings then grease it stays put. The pinion bearings and the carrier bearings run forever in gear oil. Think about this every other full floating rear has gear oil lubed bearings no exceptions why would Toyota reinvent the wheel?

on 92 itasca spirit there are 2 seals on each wheel - the wheel bearing is isolated from the rear end fluid. To get to the rear brake shoes one has to pull the axle & remove the bearing. I did a brake job and replace my seals -- got them at advance auto. I have photos if anyone needs to see.

one side had fluid mixed in with the grease (the seal between the axle & the bearing had leaked).

I do not see a reason to go in unless one is going to do the brakes -- I guess that is a reflection of mileage & manner of operation. In my mind that falls into the get it done while you are not on the side of the road. at 89k I would want to see in there. I went in at 60k & replaced the wheel cylinders, shoes & both seals on each side.

[Tom W]

I'm with Jim on this one my had about 80,000 miles looked like they had never been done, but the grease was in good shape and not a drop of gear oil in either side, Differential was full, I did repack them.

[Derek up North]

Sounds like, in your case, that repacking the rear wheel bearings whenever you happen to be 'in there' for other reasons makes perfect sense. The same way that changing a water pump while you're changing a timing belt makes sense. Following the 'Urban Legend 30k mile' schedule, you would have been due for a 3rd repacking which you say would have been unnecessary.

If your rear brakes have lasted 80k miles, it sounds like they aren't doing much work. Is the brake proportioning valve adjusted properly?

[DanAatTheCape]

[

If your rear brakes have lasted 80k miles, it sounds like they aren't doing much work. Is the brake proportioning valve adjusted properly?

all depends on how one drives -- if one anticipates stops and just lifts their foot off the accelerator pedal and coasts (which my unit does quite well) I could see getting a lot of mileage out of the brakes - front & rear. 80k does sound like a lot - I would guess a brake job has been done somewhere along the way.