M38A1CDN2 Brake Job and Hub Removal

[rob love]

Take note of the method used in the Canadian manual to repack the rear wheel bearings on a CDN3. It can also be used to repack the bearings on a Cdn2. Basically you put a whole bunch of grease on one side of the rollers, wrap it all in electrical tape, squeeze the tape, and the grease is forced through the bearings.

Note that some older M38s and M38A1s had a grease nipple on the axle housing over the bearing. This was supposed to grease the bearings, but did not do a good job. As well, if the little drain hole on the bottom of the axle housing flange got plugged up with mud (very common) and excess grease got forced into the brake area. There was a mod instruction to remove the nipples, and replace them with pipe plugs. Bearings were supposed to be repacked on the annual inspection. Truth be told, we rarely did them; usually only when a problem developed.

Also, if there is oil leaking into your brake area through the bearings, you have to replace the inner seal more so than the outer seal. The oil should not even be making it to the bearing. This also applies to the CJ7s. I saw guys continually replacing the outer seals only and not even realizing there was an inner seal.

There, I think I have exhausted that subject. I need to get these things into print: I turned 50 this summer so that means the memory will soon be gone.

[chris vickery]

Rob, I don't want to hijack Mikes post but since we are on the subject of axles and diffs, here is a question.
You mentioned re-packing bearings on the jeep.
I am using NOS axle bearings on my CDN3. THe race and bearing comes from Timken as a bonded unit, that is they are fixed together. I have read that over time in use the bearing will separate from the race and when you remove the axle, the race is let behind in the tube. This was the case with the old axle I rescued to use on my CDN3.
Anyhow, I will need to press my bearings and lock collars onto the shaft. It seems easiest to either
1) heat the bearing to 500f and retainer and slip it on,
or, failing luck with that,
2) to get it pressed on.
Option one only works with an unlubricated bearing, is it possible to hand pack it from both sides once in place or should I separate the bearing and race ass'y? How did you do in the military?

[rob love]

The heating method is OK if you have acess to an induction heater. I would not recommend the use of torches to do this job as you can overheat the bearings in spots and bugger the temper.

Pressing is fine. The bearings were packed on the axle in the method I described above: glob grease around the axle on the diff side of the bearing, wrap the glob with electric tape so you form a come from the axle to the bearing, and squeeze the tape to force the grease through the bearing. Then slide the tape cone off the axle.

I am still camping in the tent here in Kandahar, so no illustration of this method. Perhaps if someone has the Cdn 3 supplement to the Cdn2 maintenance manual, they can scan and post the photo of what I am talking about.

[chris vickery]

Thanks Rob, got it. I have the sup that illustrates the method.
I was more curious as to the bearing install. Got it too.