I've checked thru the archives here, most often I see discussion of vacuum shift vs. electric shift 2-spd Eaton rears. I have a manual shift unit, pretty positive it's original to my '40.

Started opening it up today, need to check the brakes/bearings. Took one axle shaft out, but there's a considerable degree of 'scunge' on it & what I can see down the axle tube. Now I want to open everything up & clean it out.

First hurdle is to find a 3-in, 8-point socket to get the bearing nut off.

I don't want to 'undo' something that's going to be a real pain/time waster to rectify. Any tips/pitfalls to this job, things I need to watch out for?

 

very interested! i will try too find information on part numbers,on what i did too mine so far.

 

Typically, many of us have used a cold chisel to remove those 3" nuts. Once the keepers are bent down, a couple sharp raps will get them to where they spin off by hand. Most of the trucks I've owned showed previous removal with that method. I have never torn down a rear end on these big trucks. Bearings and seals, yes when needed. Just drain it and fill with fresh. I have read old literature where you fill it with kerosene (or diesel) and drive it til warm, then drain and fill with fresh gear lube. I usually use 140 wt. If you get into those internals you are a glutton for punishment. The ancient gear lube smell alone is enough for me to just run the thing and forget about it. Just my .02

 

No keepers to bend down; just the lock nut and a one-tooth washer. This is, I believe, the Eaton 13800; 5.83/8.11 gears. I assume there's a 'pre-load' nut behind the washer, there IS some space between the washer & the bearing, but I can't see in there to tell. Drum rotates fine. Looks like this:



Put a 3-in socket on the nut tonight, with a 24-in breaker bar & my jack handle and it wouldn't budge. Hosed it down with Kroil, looking for a longer pipe. If that much leverage didn't break it loose, a chisel isn't going to.

I agree on most gear oil, tho the fluid inside mine doesn't smell much at all- quite tolerable. Maybe it's just that old (it's not dark…)

There was a noticeable, considerable amount of rusty sludge on the axle shaft. I don't believe either of the previous owners had it on the road. Owner before me didn't; he bought it in '90. Owner before him bought it in '77. It's had plenty of decades to sit & flake inside. I at least want to take the rear cover off & see how dirty it looks in there, piece of mind and all that.

 

I just did the brakes on my Eaton last winter, so you'd think I would have remembered the procedure. Fact is when I went to put them back together I had already forgotten how it had come off. What I DO remember is there is some kind of lock washer with small pins in it, or holes for pins in the sides of one of the nuts. I remember thinking it was rather clever how it locked. Don't force it until we discover the secret locking device. It must be somewhere on the web. Yes there is a preload to the inner nut. I just tap it tight while rotating and back off just a touch. Not very scientific, but I have done them that way all my life. This was my first Eaton, and my first 2 speed. Good luck when you get inside. My sludge didn't look too rusty so I felt it was ok to leave well enough alone. I drove mine on a 30 mile trip today and had fun playing with shifting the 2 speed. Thinking more about it, I think the washer has a row of small holes around the face and something has a pin in it, but it doesn't sound exactly right. Could be the inner nut has the holes and the tabbed washer has the pin. If either is the case then I guess you just gotta bust the outer nut loose. Fragments are coming to me..., but I worked 12 hours today and I'm off to bed. Maybe I'll remember when I get up at 3am to pee, and can't fall back to sleep.

 

Thanks GB, hoping it turns up. The Eaton manuals and the Canadian FoMoCo shop manual I have aren't nearly specific enough.

 

Looking in my 28-37 parts catalog (dated 1945) it appears the outside nut is a lock nut. I don't see any tab washer, etc., that has to be removed to get this nut off. Then there is a washer with "teeth" on the ID made little slots ending in half circles (this is probably a bad description). Below the washer is the adjusting nut. It appears that there is a pin that you line up with one of the slots in the washer and fits into a hole in the adjusting nut.

I am hoping that your 40 axle is set up the same as the 37 axle shown in my parts book. I am annoyed I have misplaced my 38-40 parts book. The 28-48 Green Book illustration doesn't show much.

 

Got the nut off tonight with the ol' 'chisel & BFH' routine. Just really tight.
Beneath, the washer has a dowel pin into the adjusting nut. 38 coupe- your description is solid:


Interesting that there are only 2 holes where one could (assumedly) move the dowel pin between (plus; you could flip the washer)… but in that the washer is indexed to 12 o'clock, bearing pre-load adjustability is fairly constrained. Dowel is at the '3:30' position, other hole is at the '9:30' position.

…..OR…. is that dowel meant to possibly go into the 'half moon' spaces on the washer if you wanted it to? Dowel stayed in the adjusting nut, wonder… IF it's meant to index into ANY of the spaces on the washer… why include 2 snug holes for it also?

Initial inspection shows bearings & races looking very serviceable, brake shoes are very good, wheel cylinder cups supple & without cracks. Going to open the WC and clean everything real good & inspect more thoroughly, of course.

Drained the pumpkin and got : 1/2-in of sludge, ounce or so of water, and 13 pints of gear oil. Going to pull the rear cover & try and clean it out inside, too. Dare I hope to get out of this whole servicing with just the cost of gasket paper & gear oil?

 

[doublepost]

 

Never bought anything but the seals. Everything is always in good shape! A lot of the nos ones are leather and I have found them to be of good quality. You need to soak them overnight in oil to get them pliable. Tough stuff. A company called 'Chicago Rawhide' produced many of these seals. I made a rod bearing for a one lunger on an orchard sprayer from a thick piece of shoe leather. A guy still runs it at antique engine shows and it works perfectly. Think about it... How could it knock? How could it wear out?

 

Later called CR. I've an old CR seal cabinet.

I was told by a friend (and have heard from many sources) that shoe leather was often used as a cure for worn babbitt in old Chevy sixes. This was used after all the shims were removed. Friend's dad did this quite successfully. Of course the old Chevy wasn't racing down the road, however.

 

Oh yes, and those half moon slots are also for holding the pin or dowel. Way more adjustment that way. I knew there was something clever in there behind that lock nut! As for the rawhide, I read one account of a single cylinder marine engine coming back into port with a thick piece of bacon rind in the big end of the rod!

 

Here are the hub seal part numbers for these axles. The Ford # BB1175C : C/R 3128 or National 5751. I used the National seals on my '49 F4, they are still leather like the original Ford seals. There is a large snap ring holding the seal in, that is easy to miss, as it gets covered with grease and dirt. You can make a wrench for those 8 sided nuts. I used a torch and wrapped a piece of 1/4" x 1" hot rolled flat around the nut, then welded that to a piece of pipe long enough to stick out of the hub. Weld a long handle on the pipe or cap it with a piece of flat and weld a large nut on it to use a socket and flex handle.
I had a vacuum shift Eaton two-speed in my '47 COE, I loved it. I think they shift better than the later electric shift models.
Mark Poley

 

Did some more inspection this morning: drums are excellent, races & bearings are VG, grease seal (may or may not be a leather gasket, I think it is) is also fine. Cleaning up/ deburring the pieces. Other side should be in the same condition, natch.
Will pop the pumpkin open this wknd.

 

now on my truck there probably has been some changes. i got 5 studs front axle and the rear has 6 studs. its 2 years since i had it apart but ,if memory serve me right i,v got the same lock ring. my wheel bearing were done had to replace all 4. bearing numbers are brg462,brg453x, brg3920,brg3984. now i had problems with the seal ended up useing a stemco seal which had the right inner diameter, but the exterior diameter was a bit small. so a machine shop made me a shim. now with that stemco seal i had to remove some of the grease funnel. by funnel i mean the funnel shape tin peace that keeps grease of the brakes,if the seal was to let grease go by. since i used a newer seal i believe i would not really need that . heres the only picture i took.