To Pack Or Not To Pack...rear Bearings That Is...

So I had a problem with the original rear Dana 44 that is causing me to install new wheel bearings and seals. The National A10 bearings came with instructions (imagine that) and said not to get rid of the lubrication in the bearings as they came because it is compatible with the gear oil in use for the rear...i.e. don't pack the bearings since they're already lubed and will continue to get lubed from the gear oil.

However, as you probably know, these era of Dana 44 use an internal seal that stops the flow of oil to the bearing. So, I am thinking that I just need to pack the bearings as usual with some high quality bearing grease before installing. Thoughts?

Edit to add...the TSM says to pack bearings, but I kinda doubt bearings 40 years ago came already lubed.

 

Pack em I ran without the inner seals thinking the gear oil would do it. Nope epic failure six months later new axles bearings and added a grease fitting in the rear so as to keep them lubed now.

 

If you have the zerk at the bearing then regular service will do. If not then I would do as sterlclan.

 

Thats a lesson I learned today.

 

Yeah...my driver side failed when the outer seal failed...left room for the bearing to slip out just enough to pop the whole axle. I was traveling about 70MPH on the interstate when I suddenly had no power, drifted off an exit and then noticed the wheel out about 10". Kinda scary to think what could have happened.

Purchased Alloy US (aka Omix) new axles (aftermarket is pretty slim for OEM axles), and went with premium seals and bearings.

Grease it is.

 

I have never ever seen a part fail from having too much grease.

 

I bet you have. Brakes.

 

If they do not come with grease in them, pack them. Standard procedure. Even if they are lubed by the differential lube, still pack them as it takes quite a while for the lube to follow the axle out to the bearings.

 

They don't fail, they just have the friction coefficient reduced greatly.....And if you started with 9" brakes, they didn't have to go far to be useless.

 

the only wheel end bearings that don't need to be packed are sealed hub units..
or possibly some euro crap I don't know about

 

the crusher at work ate some large bearings, both of which were very costly, the tech that came out said it was over greased, causing the temp to go up and fry the bearings.we now check temp with an ir gun

 

ditto,mine came all the way out cause the retainer got so hot the axle slid out and the whole thing passed me and flew into the snowbank as i slid to a stop.

 

Is this an owner installed option or did some come that way? Also wouldn't you run the risk of blowing out your seals?

 

Only way I see blowing the seals is if you overpack the bearings. Add two zerks that way you pull one out and force the old grease out with the new.

 

My 66 with the 44 has the factory zerk and a small hole that tells me when it has enough grease.

 

This is a '74 with a flanged axle. The flanged axles never came with a zerk fitting, AFAIK. There are two variants - the earlier design (pre-80-ish) has a seal in the axle tube between the gear oil and the pressed-on bearing, and depends on initial lubrication of the bearing for its life. The later style eliminates the seal and uses the wash of the gear oil to keep the bearing lubricated.

If it were mine, I'd pack the bearing regardless. Pack it good.

My feeling is that the instructions are telling you not to wash the bearing before assembly. If I had one of the later types with no seal, I would still pack the bearing, or at least dunk it in gear oil before assembly... and make sure the axle were plenty full of oil.

Another comment - the later axles that rely on the oil may have a deeper pool of oil than the earlier ones, ie a higher fill plug. I would be very careful before assuming that you can leave out the seal and depend on gear oil if the axle originally came with a seal.

 

Great thoughts Tim. My intention is to follow the TSM. I figure by the time they got to the '74 Dana 44 they actually knew what they were writing about. I'm keeping both internal and external seals and have some very good bearing grease that will be packed in the bearings and any voids in that cavity.

My biggest problem is keeping the axle square to the bearing and retaining ring when pressing it on via the HF 20 ton press I have.

 

Warming the bearing and retaining ring somewhat will help considerably. I would not exceed 300-deg as the bearing steel can be tempered back (softened) at about that temp. Yard sale toaster ovens are great.

 

another vote here for sure pack them well upon assy. My 74 cj5 is still running on the factory bearings and seals at 120k miles. Only time I ever serviced them was at about 40k, the factory wheel brg grease was still there and looked good. Cleaned them checked inner and outer seal and re packed with a good quality wheel brg grease, not simply chassis grease.