Need the skinny on wheel bearing removal and packing?.....

[Nickathome]

Now that my truck is licensed and ready to roll, I'd like to tackle one job I have been putting off, and that is inspecting and repacking the wheel bearings and oil seals. I realize I should have probably done this when I was tearing into my brakes but it didn't get done and thats water under the bridge so to speak.

I have been really thinking heavily about doing this now that I am able to drive the truck. Is the procedure difficult? What tools would I need for the job, other than that big socket for removal of the retaining nuts(BTW what size is it?). I'd like to get this job behind me as soon as I can. Any and all advice appreciated.

[MSeriesRebuild]

Now that my truck is licensed and ready to roll, I'd like to tackle one job I have been putting off, and that is inspecting and repacking the wheel bearings and oil seals. I realize I should have probably done this when I was tearing into my brakes but it didn't get done and thats water under the bridge so to speak.

I have been really thinking heavily about doing this now that I am able to drive the truck. Is the procedure difficult? What tools would I need for the job, other than that big socket for removal of the retaining nuts(BTW what size is it?). I'd like to get this job behind me as soon as I can. Any and all advice appreciated.

2 9/16" octagon is the socket size you need. It isn't a hard job, once nuts are off pull the hub/drum assembly from the spindle being careful not to let the outer bearing cone drop on concrete. You may have to loosen the brake adjustment to slide it off. Remove the seal retaining snap ring & pry out the old seal. You can now remove the inner bearing cone. USE CARE: if you are pulling more than one wheel before re-assembly, be sure you keep the bearing cones with the hub they came out of. A wear pattern is established & putting the cone back into a different cup will shorten the life significantly. Clean the bearing cones thoroughly in solvent & blow dry with compressed air using care not to spin the bearing with air pressure. Inspect very carefully under a good light, bearings most often start to break down 1st on the inner race surface. If you notice areas on the inner race, outer race (cup in the hub) or the rollers that have rust damage or has started to flake out, replace the whole cup/cone assembly, they are well on the way to failure. You can re-pack with a premium brand of NLGI#2 grease, we prefer Synergen or Hydrotex brands as these products don't sling out of the bearing. What you put in stays in, many cheaper brands will sling out or melt down & run out under the heat generated by braking. A bearing packer is by far the best bet for full even lubrication although the cones can be packed by hand if you chose. Re-assemble in the reverse order of tear down using new current production rubber seals. The rears have an inner & outer seal, the fronts have the inner only. Using NOS or leather seals as always is a waste of time & $$. When re-installing the spindle nuts, torque to 100 ft.lbs., spin the hub several revolutions, retorque, spin hub again, etc. Follow this sequence as many times as it takes to make the nut hold 100 ft.lbs of torque after spinning the hub. **While holding the drum, back the nut off 1/6th of a turn, (the distance from 1 axle flange stud to the next is a good gauge to use). Now install the lock washer & outer nut. Follow the same torqueing sequence for the outer nut, torque to 100 ft.lbs., spin, re-torque until it holds 100 ft.lbs. I'm sure someone will say spinning when installing the outer nut won't matter since the inner nut is holding the torque. Well it does, so tighten & spin until it holds 100 & you're done except for installing axle shafts in the rear & caps on the front.

[Nickathome]

Charles;

Thank you immensely for this info. Much appreciated. I do have one more question, Can I get the oil seals at NAPA, and if so, what are the numbers? Thanks.

[CGarbee]

The numbers that I have on my website's PDF parts cross list are:

AXLE FLANGE GASKET PAPER, NAPA J26288

AXLE SEAL INNER HUB OIL SEAL, NAPA 49426 or CR 28116

AXLE SEAL AXLE OUTER OIL SEAL-FLANGED, NAPA SS49857 or CR 20766

I've been buying these parts from a dealer for years in quantity, so I can't personally vouch for these numbers, but more than one person sent them to me back when the list was compiled...

The full list is located (in PDF form) at:
http://www.garbee.net/~cabell/PartsCross.PDF

If you do try these numbers and find that they have been updated, etc., please let me know...

Remember that they should be the same as on a civilian Dodge Power Wagon (say, a 1950 B2 or a mid-sixtees WM300) if they have problems with the numbers and you want to give them an application (although not that likely to be in the computer these days... ).

[peter e mark]

Hello Talbert, sure can't add much to your work description, but I do have a question: How come so much torque on the axle nuts? In the Army I was taught to tighten them a bit looser, or so it seems. What is your source , please?

[ELBUFO]

Ok, This may be redundant but...Once the bearing is thoroughly clean, put a big blob of grease in the palm of one hand. Grasp the bearing in the other and push the edge of the back side of the bearing into the edge of the blob of grease This will be like you are trying to scrape the edge of the grease out of your hand. After a few passes you will notice grease coming out through the rollers on the top side of the bearing. Rotate the entire bearing slightly and repeat. Once you have the entire bearing done in this manner coat the outer surface with about 1/2 inch of grease. install into hub assembly. Some people like to fill the area between the bearings with grease, but this is not necessary, and only makes a big mess when you do your next re-pack. I have done it both ways in the past, and have noticed no difference in bearing life. When you go to tighten the inner nut, run it down snug, and rotate the hub and assembly. Re-snug the nut. Do not over tighten. A little pre-load is ok, but not to much. I usually do mine a scant 1/8 turn, unless "The Book" calls for a specific torque. An extra step I recommend is after a quick trip around town or so, recheck the snugness. If you have failed to fully seat your races it will show up now, once everything has settled in. yea ya might blow a hub gasket doing this but they are cheaper than bearings. Once this is all done you should be good for a couple of years. If you can afford it use synthetic grease of the proper specifications. As a matter of fact I use synthetic lubricants everywhere. they are pricey, but I have been doing it for years, and it does make a difference. Check out AMS Oil products. You can't go wrong NOTE: use a race driver to install races, If you don't have one use a brass drift. NEVER use hardened steel like socket extension, It is possible to chip the race or the tool. I am quite fond of the piece of shrapnel in my leg from being stupid. Hope this helps...John

[MSeriesRebuild]

Hello Talbert, sure can't add much to your work description, but I do have a question: How come so much torque on the axle nuts? In the Army I was taught to tighten them a bit looser, or so it seems. What is your source , please?

I did this hurridly during lunch, after reading over it I discovered I left 1 step out of the sequence, so here is a correction. I also went back & added this step to the original post. It is marked there with **.

After torqueing the inner nut to 100 ft.lbs., hold the drum still & back the nut off 1/6th of a turn, then install the lock washer. Install the outer nut & torque to 100 ft. lbs. using the instructions posted previously. The initial high torque is so the bearings are seated properly. Once the nut is backed off 1/6th turn, you will note that all is well when you rotate the hub/drum assembly.

I got this method from the instruction sheet that used to be included with National hub seals years ago, (they no longer include instructions). I ignored it for years doing it by feel, but decided to try it one time. I found it is a fool proof way of doing it real fast. All wheels are exactly the same with a correct bearing preload & never the first problem after doing hundreds. Running bearings too loose will kill them very quickly, this method will prevent that from ever happening. There will be no need to pull anything back apart to recheck if this method is used. As for not seating a race in the hub properly, well if you are paying attention to doing a good job, that will never be an issue. It's no problem at all to tell when they have hit bottom against their seat.

As I originally said, packing with a packer is better, faster, & far less messy, hand packing is fine also if you don't have access to a packer. However over packing a bearing isn't good, serves no purpose, & can even cause a bearing to overheat if the excess lubricant can't escape. In the case of the M37 hubs, excess lube will eject into the hub, so over heating for this reason isn't an issue in this case. It's the grease between the rollers that does the job, anything more is really overkill. I always just rub a thin skim over the outside of the rollers after packing, applying any more than that just creates more mess to clean out next time as someone already mentioned. Just remember any grease that isn't between the rollers in the cone will never get where it does any good at all, thus is wasted. Premium quality grease is costly, wasting it is senseless.

[MSeriesRebuild]

Charles;

Thank you immensely for this info. Much appreciated. I do have one more question, Can I get the oil seals at NAPA, and if so, what are the numbers? Thanks.

I don't generally buy seals at NAPA, we use National. Those numbers are: inner seals, 417485, 4 needed. Outer seals National 6077, 2 needed. We don't use the paper gaskets at all, but use anaerobic gasket sealer/maker instead. A far better seal will result.

**NOTE: Re-read the original instruction post, I omitted a step in the original post & have edited the message to correct that.

[ELBUFO]

COOL ..Thank you for the tip on pre-load specks. The method I had indicated was the old when in doubt this works. It would be interesting to know what the actual pre-load torque is after backing off 1/16 turn. I am going to have to bust out the torsion torque wrench and find out. It will be a while till I do the brakes/bearings, due to cost overrides, as the bank of my old lady only lets me spend so much a month. I will post my results. If someone knows already even better.
As to paying attention, It is possible to have a race hang up on ridge and cock ever so slightly. The race will even make the nice ping sound when it bottoms out. I have only had this happen once in 20 years as a vehicle maintenance puke in the USAF. It just so happened to be on my own rig. I remember it well. Call me gun shy, but from that one on, I always double checked my work,...I hate walking.

[MSeriesRebuild]

COOL ..Thank you for the tip on pre-load specks. The method I had indicated was the old when in doubt this works. It would be interesting to know what the actual pre-load torque is after backing off 1/16 turn. I am going to have to bust out the torsion torque wrench and find out. It will be a while till I do the brakes/bearings, due to cost overrides, as the bank of my old lady only lets me spend so much a month. I will post my results. If someone knows already even better.
As to paying attention, It is possible to have a race hang up on ridge and cock ever so slightly. The race will even make the nice ping sound when it bottoms out. I have only had this happen once in 20 years as a vehicle maintenance puke in the USAF. It just so happened to be on my own rig. I remember it well. Call me gun shy, but from that one on, I always double checked my work,...I hate walking.

The back off spec is 1/6 th of a turn, not 1/16.

I always roll the hub over & check with a mirror to be sure the bearing cup is seated correctly against the bottom flange. I'm with you on not wanting to walk home, but I hate to pull stuff back apart just as bad.

[ELBUFO]

Quite a difference between a 1/16, and a 1/6 turn. I am with ya on the inspection mirror. I can't remember what day it was I had the hang up on but it was probably a Monday again thanks for the specks...John