M809 Series- Front axle work and what to expect

[Ajax MD]

Just a few quick questions that weren't quite answered by my thread searches or the TM.

There are several good Youtube videos on steering axle boots, hub and axle work but they're nearly all for the 939 series trucks with air brakes, which doesn't apply to me. Also, real life seems to contradict the TM in a few places.

1. In the 809 trucks, will the inner wheel bearing be captive in the back (inside) of the brake drum when I remove the drum, or will the bearing remain on the spindle when I pull the drum off? (TM/Youtube contradiction here) The TM makes it seem that the bearing is held in the drum by the grease seal but YT videos show the opposite...but those are 939's. I thought the grease seal would stay in the drum, trapping the wheel bearing inside?

2. In YT videos, I keep seeing people removing the whole knuckle when pulling the axles. The TM says to withdraw the axle from the steering knuckle, just be careful not to jostle the oil seal. Can I leave the knuckle on? What's the big "tell" if I have an oil seal leak? (I bought oil seals but I'm not replacing them if they're not leaking.)

3. I'm replacing the boots with new, zipper boots. My truck is a '71 so I figure I have a 50/50 chance of having the old style (Timken?) or newer universal joint style of CV joint. Can I view the CV joint when the boot is removed? Do I really have to pull the axles? There is no groaning, grinding or clicking noises from the front end. On the jack, the front wheels spin smooth and quiet, with no play.

I can tell you this- I have a (very recent) small split in an axle boot and it has slung some tired grease out onto the tire but there is not "oil" coming out and the oil level in the front axle is normal.

Basically, I'd like to re-pack the wheel bearings, inspect the brake shoes and hydraulic wheel cylinders, verify that I don't have an axle oil leak, peek at the CV joint from the backside, and put it all back together. The brakes work very well and I'd like to avoid opening the system by removing the brakes just to look at the CV joints if it's not strictly necessary.

Does this sound acceptable?

 

[US6x4]

The inner wheel bearing will be captive in the hub held in by the inner wheel seal.

I had gear oil gushing out of my hub as soon as I removed the hub cap which was the sign that mine had an axle shaft leak, but a lesser leak would be harder to find. I would guess that any gear oil beyond that seal means the seal is not sealing.

To repack the inner bearing you'll have to remove the wheel seal to get the bearing out and if you're careful removing it you can reuse the seal.

I've read where guys have removed the brake backing plate without opening or disturbing any of the brakes and just moved that whole assembly to the side & hung it from the frame grip handle in order to remove the axle shaft w/o removing the knuckle/king pins.

If you have zipper style you don't have to remove the axle shaft and you should be able to see the joint with the boot removed.

 

[Floridianson]

Agree with everything but using the old hub grease seal . New seal is the way I would go.

 

[Ajax MD]

I have new grease seals as well so no worries there. Thanks for all the great answers. Looking forward to getting into it.

 

[Brutacus]

Just a few quick questions that weren't quite answered by my thread searches or the TM.

There are several good Youtube videos on steering axle boots, hub and axle work but they're nearly all for the 939 series trucks with air brakes, which doesn't apply to me. Also, real life seems to contradict the TM in a few places.

1. In the 809 trucks, will the inner wheel bearing be captive in the back (inside) of the brake drum when I remove the drum, or will the bearing remain on the spindle when I pull the drum off? (TM/Youtube contradiction here) The TM makes it seem that the bearing is held in the drum by the grease seal but YT videos show the opposite...but those are 939's. I thought the grease seal would stay in the drum, trapping the wheel bearing inside?

2. In YT videos, I keep seeing people removing the whole knuckle when pulling the axles. The TM says to withdraw the axle from the steering knuckle, just be careful not to jostle the oil seal. Can I leave the knuckle on? What's the big "tell" if I have an oil seal leak? (I bought oil seals but I'm not replacing them if they're not leaking.)

3. I'm replacing the boots with new, zipper boots. My truck is a '71 so I figure I have a 50/50 chance of having the old style (Timken?) or newer universal joint style of CV joint. Can I view the CV joint when the boot is removed? Do I really have to pull the axles? There is no groaning, grinding or clicking noises from the front end. On the jack, the front wheels spin smooth and quiet, with no play.

I can tell you this- I have a (very recent) small split in an axle boot and it has slung some tired grease out onto the tire but there is not "oil" coming out and the oil level in the front axle is normal.

Basically, I'd like to re-pack the wheel bearings, inspect the brake shoes and hydraulic wheel cylinders, verify that I don't have an axle oil leak, peek at the CV joint from the backside, and put it all back together. The brakes work very well and I'd like to avoid opening the system by removing the brakes just to look at the CV joints if it's not strictly necessary.

Does this sound acceptable?

1 The inner bearing will held in place by the grease seal. You will have to remove the old seal to clean, inspect, and re-pack the bearing with fresh grease. Since you have it all apart, replace all seals with new.


2 Remove the steering knuckle. It will save you some time. Loosen the castle nut, take the tie rod off, and remove the knuckle. It will make the reassembly easier. Since you have it off, clean, degrease, and paint it while you at it. With everything out of the way, go-ahead and replace inner oil seals. You've already broke down to the seals, so get the old ones out and the new ones in. If you don't know how old the seals are, don't risk it. This would save you another tear-down in the future.

3 Zipper boots can replaced without having anything else torn down. To inspect your axle shafts you will have to remove the spindles, which require removing the brake mounting plate. It's a good idea to take everything apart to inspect it, clean it, re-pack with fresh grease, and reassemble with new seals.


I recently went thru my front axle. I found excessive dirt and water in the grease of both hubs on my front axle. I had to replace both inner bearings due to excessive wear, all the seals, new hardware for the brakes, new ball bearings for the Bendix style axles, and a lot of fresh grease.


You can re-pack the wheel bearings, inspect the brake system, check for an oil leak, peak at (not inspect) the axle u-joint(CV joint) when you remove the dust boot, and put it all back together.

I had to replace all my brake parts (frozen cylinders) and wanted to make sure everything was clean and up to spec. That's why I tore my axle all the way down to the axle housing. After seeing what was on the inside, I would suggest anyone who has an M809 series truck that is new to them, that they do a complete tare down, cleaning, and re-assemble with new seals, fresh grease, and replace parts as necessary.

Oh when you replace the inner grease seal, if you don't have a seal seater tool, you can use a block of metal, the splined hub cap, and a heavy hammer to seat the new seal. Just don't hit the pressed in grease cap on the splined hub cap.


after

 

[Ajax MD]

Brut,

Thanks for that. I would not have expected to need that much force to install the inner grease seal. Those are some dry bearings.
The one thing I haven't bought in advance, is wheel bearings and races. I figured I'd just have to leave the front end apart and order them IF needed.
I should have bought a gallon of brake fluid.

I'm not afraid to tear things down further if stuff is looking ugly. We'll see what it looks like once I get to the first stage of bearings, brakes and boots.

 

[Brutacus]

I just required two taps with my method. You don't want to smash the living daylights out of the seal. Another factor that helped installing the seals was freezing them. I put my seals in a freezer bag, then kept them in the deep freeze over night. That helps them contract a little bit. It also helps if the hub is warm or hot too, like in August.

You can't be overprepared for this job. I had my truck sitting on jack stands for a week in my driveway waiting on bearings and races. My bearings had plenty of grease, but also a lot of water too. My stuff was ugly in the front and rear. I ended up rebuilding/replacing almost the entire brake system, and rebuilding all 6 hubs. Once your done with your hubs, don't forget to drain and replace the differential oil. If you had any leaks, chances are you might have some water in the differential. I know I did.

 

[Ajax MD]

Man, your work is top quality. Very clean.

I'll put my seals in the freezer tonight.
I have already drained and filled the transmission, transfer case, and checked the differentials. The fluid in the differentials was clean, no water and smelled clean and correct. The rear axles are clean and dry with no sign of any leakage.

My plan is to do the steering axle first. There is a local fellow who has a "duals jack" that makes rear axle work much easier and more efficient. Once the steering axle is done, I will see about bringing my truck to his place to do the rest of the truck.

 

[Brutacus]

Thankx, it only looks good because I listened to the advice from the people here.

Any water in your differentials will in the bottom at the drain plug. You can turn the plug open slightly keeping the plug in so the oil just drips out. If there is any water in there, you'll see it first.


Oh if you have a pressure washer, it would be a useful tool for cleaning any of the brake components. If you want to keep your work area clean, get a small oil catch pan, and use a drop cloth or a small cheap tarp. When you start taking things off, there might be some oil, or some very runny grease dripping out. That stuff makes a HUGE mess. After you setup your jack stands, just lay the tarp down, when done roll it up and throw it way. Makes clean up very easy.

 

[Ajax MD]

Yep, bought a pressure washer to clean the truck (and other sundry household items). I have a pile of tarps and drop cloths and catch pans.
I have brake cleaner spray, also. And nitrile gloves. I'm expecting a big mess.

 

[topo]

When Putting in the seal I have found that using large washers on bolts threaded in to the holes around the seal to help hold the seal square and tap it in .
The drum sit just high enough to pinch fingers when taping in the seal .

 

[Ajax MD]

Today has not been great. Not because of the truck, but because of constant interruptions.

Bottom line: I've got the passenger's side apart. Everything went beautifully, Soldier B Hub Helper worked a treat. Everything inside is CLEAN. I mean, it was incredibly clean when I took it apart, not that I have cleaned it. Brakes look great. No rust anywhere. Outer wheel bearings look very good, only minor wear. No spalling, pitting, scorching, bluing, corrosion or anything.

Here's where I'm stuck: The !#@$ inner seal won't come out. I've tried Wes' pry bar/sledge trick and it's not budging. I'll re-watch the video but if anyone has any advice to get the inner seal out, I'm all ears. I'd like to get the passenger side reassembled tomorrow.

 

[Ajax MD]

Re-watched Wes' video. I did exactly the same thing, I know I hit just as hard but that thing wouldn't budge. The only thing I can thing of, is that I was hooking the pry bar under the wrong thing inside the hub.

 

[Brutacus]

Re-watched Wes' video. I did exactly the same thing, I know I hit just as hard but that thing wouldn't budge. The only thing I can thing of, is that I was hooking the pry bar under the wrong thing inside the hub.

Set 2 boards on the ground, set the hub/drum assembly on the boards so the drum is the only thing touching the boards, this will get it of the ground. Make sure the seal is facing down and is not resting on the boards. Now you can hammer down to get the seal out. If that doesn't work, try making up new curse words, and throwing your tools at it. I tried both, the former works best.

 

[Ajax MD]

Alright, it seems that I kept hooking the surface of the drum inside, missing the lip of the seal. You have to hook the seal lip kind of in between the bearing which is not quite what I expected. Dog-dangit, I didn't even have to hammer, I just needed to pry up!

A couple quick photos for your amusement.

 

[Ajax MD]

The inner wheel bearing also seems in excellent condition. No axle oil anywhere. I peeked under the brake cylinder boots and it's all clean and dry under there as well.
I was interrupted before I could get the knuckle boot off, so that's tomorrow's task.

If the CV joint is as clean as everything else, I'll put the new boot on, grease everything up and put it all back together. I'm only going to get one side done this weekend, unfortunately.

 

[Ajax MD]

Alrighty, got the passenger side all greased up and re-assembled. This was my first time doing a hub with inner/outer bearings. Following the TM, I could definitely feel the bearings get settled in as I spun the drum while tightening the inner lock nut. An interesting sensation. The fresh grease makes that hub spin smooth, like butter and totally silent.

I get to do it all over again next weekend on the driver's side.

 

[Robo McDuff]

Great thread, just when I need it, but NOT ENOUGH PICTURES..



Driver side is the first I will tackle to check the breaks, no evidence of leaking seals. Will also replace the socks with zipped ones.

A few questions, because I am in the Czech Republic, and no US truck part suppliers near me. So I would like to reuse or leave the seals as is unless they leak.

- Can I remove the axle without draining the oil or will it run out?

- Are seals very specific M39 - M809 or is there a chance that any specialist in hydraulics or automotive supplier will have fitting seals in EUROPE?

- what is the best grease to pack the bearings with or will any old grease do?

- would it help save the seal if I only pulled the axle far enough to get the hub away from the brakes (balanced on a solid construction) but leave the axle in? Or is that a very bad idea?

 

[Ajax MD]

Great thread, just when I need it, but NOT ENOUGH PICTURES..

View attachment 781938

Driver side is the first I will tackle to check the breaks, no evidence of leaking seals. Will also replace the socks with zipped ones.

A few questions, because I am in the Czech Republic, and no US truck part suppliers near me. So I would like to reuse or leave the seals as is unless they leak.

- Can I remove the axle without draining the oil or will it run out?

- Are seals very specific M39 - M809 or is there a chance that any specialist in hydraulics or automotive supplier will have fitting seals in EUROPE?

- what is the best grease to pack the bearings with or will any old grease do?

- would it help save the seal if I only pulled the axle far enough to get the hub away from the brakes (balanced on a solid construction) but leave the axle in? Or is that a very bad idea?

Yeah, sorry about that. Everything requires 2 hands, and I work alone so no free hands for the camera. There is a great thread over in the deuces forum that just got started that has a ton of photos. The process is very similar to non-air brake 5 tons.

The seals are listed as "Seal, plain, encased." That would seem to indicate that they are a common type of seal used in plenty of industrial and agricultural equipment. Your best bet is to remove the old seals without damaging them and visit heavy truck and agricultural shops in your area and see if they can match something up. Also, you could contact our vendors here and see if they can ship you something. Just remember- These are old, Imperial measurement trucks. European parts will likely be metric.

You can *carefully* remove the inner wheel bearing grease seal without damaging it and possibly re-use it. I preferred to replace with new.

Removing the axles- Some oil will run out, but not a lot. You could drain maybe a half gallon from the differential and have a fairly dry experience removing the axles and axle tube seals.

Regarding grease- Oh my... there is a whole religious cult here devoted to grease. There are endless arguments about grease in the archives. I can only tell you what I did:

I downloaded the specifications for GAA (Grease, Automotive & Artillery) which is MIL-PRF-10924. Then, I researched various commercial greases until I found some that met (or approximate) the same specification (even if they don't specifically say that they meet MIL-PRF-10924).

- Castrol Braycote 610 specifically states that it meets the MIL-PRF-10924 standard. It seems that it is only sold by the pail, for around $400 for a 35lb. bucket. Not available in gun cartridges, as far as I could tell.

- Shell Rotella HD grease meets the specification and is a Lithium complex grease like GAA but does not specifically state that it meets the 10924 specification.
- Lucas brand "Red 'n Tacky" grease also met the specification as far as I could tell. These are both available by the can and in cartridges.
- Lucas brand "HD Grease" is polyurea based and NOT chemically compatible with Lithium complex greases so I ruled that one out.

In the U.S., we have a classification system called NLGI. GAA is NLGI-2, which indicates a consistency similar to peanut butter. So the bottom line is, you want to stay within the same chemistry and consistency. Use a Lithium based grease with consistency at least as firm as peanut butter. If you mix chemistries, (calcium or polyurea-based grease with Lithium complex) they are incompatible and will basically dissolve into a useless goo that doesn't lubricate very well.

Don't worry, at least 5 guys will come along in a few minutes to tell me how wrong I am about grease. These are all just my own, personal conclusions.

Hey, I still have to do the driver's side so I have opportunities to take more photos.

 

[Ajax MD]

In other news, I wrapped up the passenger's side by replacing the knuckle boot yesterday after work. Like wrestlin' a greased hog but not too bad. I cleaned out all the old grease, which was thin and tired, but not "runny." No sign of axle oil leaks, no water and no corrosion on anything.

I have the older Bendix CV joints. Because these are sort of exposed, ball bearing CV joints instead of enclosed, needle bearing universal joints, I think it's probably correct to follow the TM and pump in the ridiculous amount of grease called for. I will remember to remove the little Allen screw vents so I don't blow the boot off of the knuckle.