5 ton rear axle seal fix procedure

Well I finally went ahead and tore into the rear axle to replace the seals. It was not very hard. Just heavy. I followed the proceure from "dm22630" and there were no problems. I tried to document everything with photos so others can see what's in there before they start.

1. Park on a FLAT surface & set your parking brake.
2. Chock wheels.
3. Jack up the leaking side of the axle.
4. Remove both tires.
5. Remove axle shaft.
6. Remove axle nut, lock nut, outer wheel seal, & outer wheel bearing.
7. Remove hub/drum assembly (80+ lbs....DONT slide across your axle threads!).
8. Remove inner wheel seal & inner wheel bearing.
9. Clean everything (brake shoes, brake drum ** clean & lightly sand to scar surface **, remove all old wheel bearing grease & gear oil from inside hub).
10. Pack bearings.
11. Install inner wheel bearing & inner wheel seal.
12. Install hub/drum.
13. Install outer wheel bearing, outer wheel seal, lock nut, & axle nut.
14. Insert axle shaft & remember to use high-temp RTV sealant to seal completely.
15. Reinstall tires.
16. Remove Jack.
17. Fill gear oil in that axle.
18. DONE!

More.....

Still More.....

Evenmore......

And even more!!

GREAT JOB

Excellent write up with pictures. I am planning on doing this soon to both my 5 tons so this is a great help to me!!

Great write-up.
Could you have put the inner bearing and seal into the hub prior to installing the hub? I never did a 5 ton, but that is how I've done every other vehicle.

Anyone know the proper size wrench for the 5 ton hub nut?

jpekarek your write up and pictures are better than any I have ever seen in a service manual. Thank you for going the extra mile and posting it up. I am getting the parts together to do this to one of my XM818 axles soon.

drgreg said:

Great write-up.
Could you have put the inner bearing and seal into the hub prior to installing the hub? I never did a 5 ton, but that is how I've done every other vehicle.

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Yes you could, but I didn't want to risk dragging the seal across the axle threads or messing it up some how. If you place it on the shaft first, it slides right into place with almost no effort.

MWMULES said:

jpekarek your write up and pictures are better than any I have ever seen in a service manual. Thank you for going the extra mile and posting it up. I am getting the parts together to do this to one of my XM818 axles soon.

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Hey you're all welcome. You guys have posted a lot of helpful information that I have used to fix my big green machine. Lease I could do.

Very nice! That write-up will be referenced for years to come by many. Thank you!

Nicely done but I disagree with putting the seal on the spindle and letting the hub press into it. I've seen plenty of seals (too thick) that wouldn't force the inside bearing to align the hub before seal contact is made. I always do it the other way. Did you back the hub out to make sure the seal seated properly?

Stalwart said:

Nicely done but I disagree with putting the seal on the spindle and letting the hub press into it. I've seen plenty of seals (too thick) that wouldn't force the inside bearing to align the hub before seal contact is made. I always do it the other way. Did you back the hub out to make sure the seal seated properly?

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Good point, didn't think of that. I did pull the hub back out and check the seat, it looked good in my case. The TM from the Resource section says to use this method. But installing it in the hub is probably a better method, as long as you are careful with that heavy brake/hub assembly.

I'm with Stuart on this one - they make some pretty cheap little 1/4 ton chainfalls and come-alongs that we use for the little stuff at work all the time - when it's too bulky to pick up gracefully but you don't need a huge hook... Plenty of places to hook off the bed; I would just weld a little pad eye (chain links work well) over each one so it's a no brainer...

The other trick we use for seals is to use a piece of heavy mylar or even sheet metal wrapped around the area of concern (in this case the threads and keyway) to make a nice smooth sliding ramp. Alot of large 2-stroke diesel fuel gear uses o-rings with teflon carrier rings that need to be stretched over nasty edges and then pushed into place - then you use a collar to shrink the teflon seal back into the groove.

Great write up though - I need to do the left side midships hub on my M-543a2... she drips a little; along with the forward rear axle pinion seal...

Regards

Matt

Excellent step-by-step. You should produce a line of MV maintenance books.

I am confoosed... as usual. I have never done a 5-ton axle, so this is purely a question and not a second guess. Anyway, on all the full floater axles I have done, there is only one inner seal at the back of the hub, and the hub's bearings are lubricated with gear oil. But on this thing you have that outer seal and are packing the bearings with grease. So I guess my question is does the gear oil lubricate the hub bearings at all, or are they completely dependent on the grease you repacked them in? One would think the outer seal is a bad thing since gear oil would be a much better lubricant, and the flange gasket should keep everything in the axle.

Also I little trick that I use, when you pull the drum/hub off the spindle, Place a 5gal bucket at the end of the spindle, (open side up) slide the hub off the spindle and into the bucket. This will leave the brake drum up out of the bucket so when you brake clean the whole assy. all the grease/crud goes into the bucket. When you are ready to put the drum back on, it is already at the hight it needs to be, all you need to do is slide it onto the spindle.