knuckle seals

[HULLROAD]

I was working on replacing the knuckle seals on my M38A1. I ordered new seals from a local shop and the ones on the left (if the pic turns out) were what they sold me. When I pulled mine off I see they look like the ones on the right. The replacements are, according to the shop, all they have for 41 to 71 closed knuckle dana axles. What they sold me will work and the seal itself looks better as it is one piece and has a felt wipe that the original does not have but the retainer on the replacement is just tin.
I was wondering if anyone else had used these REPLACEMENT ones and if they held up OK. Or should I find original seals from a specialty supplier.
Also wondering what others did with the surface that this seal rides on at the axle housing.....Did you paint them, leave them raw, or maybe use some cosmoline or something else to keep it from rusting.
One other question...How much grease do you put in your knuckle joint? Mine was packed full with a few different colors of grease. Looks to me like someone just kept packig more on the axle and never cleaned the old stuff out. I can not see how all that extra grease slung to the sides could be of any use to the axle joint, but my uncle always said "if a little is good, a lot has to be better". Don't know if that's the case here as I have manual locking hubs and the axle will not be turning other than when in 4 wheel drive so packing it full should not be needed....unless I am missing something.
Just looking for some input from someone who might have done this already. Thank you in advance....PS if the photo is not in this post....it IS in my album, I at least figured that part out so far. Thank you in advance

[wesk]

I have used the old style and I believe maybe once or twice that newer style but I don't recall in which axle I used the newer style.

The Army developed the procedures in the manual and the grease specs in the manual for a 6,000 mile disassemble, clean and repack by hand regimen. The grease they spec'd is plain old NGLI 2 chassis lube.

The early Willys/Kaiser service manual for the CJ's SM-1002 specifies a thinner chassis lube and refer to it as U'joint lube using 0 weight in the winter and 1 weight in the summer. Check level each 1000 miles and clean and repack each 12,000 miles or 12 months whichever comes first.

The later Kaiser service manual SM-1046 specifies a gear oil GL3 SAE 140 year round and a service each 2000 miles and clean & repack each 12,000 miles.

Over the years dozens of home concoctions have surfaced under the title "Knuckle Pudding" and were experimented with to find a lube thick enough not to seep out and drip on the floor and thin enough not to slow the axle down in the winter and still get slung towards the king pin bearings. Most work to some degree but none were ever proven to be perfect. CV joint lube has been used as well as corn oil grease and 600 weight antique Ford axle lube. The degree of success with eliminating the two puddles on the floor depended mostly on the quality of the seals and the cleanliness and smoothness of the knuckle area the seals rode on.

You should obtain the highest quality seal you can find. Then polish those knuckle spheres in the seal operating area until they are smooth as an infants arse. Then paint that area of the sphere with clear lacquer. Grease the lacquered area well after it has dried thoroughly. No matter what choice you make on knuckle lube always hand pack the king pin bearings with a quality chassis lube NGLI 2.

Follow the assembly instructions in the manual to the "T". Set king pin turning friction as spec'd. Set axle float per the correct procedure for the type axle you have.


Here's the differences in axles. The rest of the pages from the civvy SM-1002 service manual are in my photo album so you can properly set up whichever type axle you have.

http://www.willysmjeeps.com/v2/modules. ... _album.php

[HULLROAD]

Thanks wes,
I have Bendix type axles.....I cleaned all the old grease off, they are in great shape and don't show any sign of wear yet. Guessing mine has had the locking hubs on it for a L O N G time. since everything still looks new in their after 61 years.
Sounds like you are saying the seals must work OK. I am sure you would remember if the things leaked after all the work to change them. That is why I was afraid to use them. I did not want to have to do it all over again.
I took a scotch bright pad (scuff pad) after the knuckle spheres and polished them up...their was no paint left on mine just a thin layer of grease that had been sweeping past the old seal. I was wondering how to keep them from rusting once the seals were replaced. I was afraid to paint them. I did not want it to ware off and get stuck in the new seal but that is why I asked here. I figured someone has done it and would know what worked.
Yes I am going to repack the king pin bearings with a bearing packer before I install them, It's a little less messy than hand packing. I am going to bring my packer home from work and do that tonight. I seen all the posts about the grease "MIXES". I have decided on the SGLI 2 lube already...figured if it has worked this good for this many years ....I'll stick with it.
Any thoughts on HOW MUCH grease (SGLI 2) to pack in the knuckle around the Bendix joint? I am going to repack the Bendix joint on the bench before I install them. I will be able to force grease through the balls while flexing the joint and make sure everything is greasy. The problem I have is I never seen anything explaining HOW MUCH to pack in the knuckle.....just to service the joint at regular intervals. If you used the SGLI 2 how much excess did you put around it. Thank You again.

[wesk]

As the manual clearly states fill with lube to the filler plug hole.

If you are in the UP or up near the top of the LP then you'll find the thicker NGLI 2 will create a lot of rolling resistance below 10 degrees. The best lubricant will allow a very light seep past the seal to keep the spheres wet with lube which will handle any rust issues. If your goal is to have absolutely no seepage and clean dry spheres you will have to pack a really thick grease in there and clean the spheres by hand every dirty trip you make.

My suggestion is to go with the SM-1002 or SM-1046 instructions. Use NGLI 0 first then if seepage is too much switch to NGLI 1 in your climate. But no matter what you fill the knuckle to the filler hole with always use NGLI 2 when packing the two king pin bearings.

If you could talk to an original Willys engineer from the 40's they would tell you they designed the kinuckle and spec'd the lube to purposely allow for a slight seepage to keep the exposed sections of the spheres lubed.

[skyjeep50]

I've owned a CJ3A and currenty have a M38 and M38A1. The civilian jeep came with the set of seals on the left in the original post pic, the military jeeps came with the seals on the right. Your local supplier said he only had the ones on the left because he was looking at civilian parts books. Military parts tend to be a specialty item - try the the military parts houses. Both types of seals will probably work fine. Also, cleaning up the front axle will enable you to adjust king bearing pre-load - a important part of controlling steering slop and "wobble". I've gone the pudding route on my jeeps, no drips, no runs and the stuff will flow to a certain extent into the Bendix. Not saying that is the only way to go but I'm trying different things to see what works best. The knuckles don't have a chance to rust because they get wiped with lube every time you turn the wheel. Might be a problem if you park the jeep for a couple of years but not if you drive it every so often.

[HULLROAD]

Ok...I am not trying to start the "grease" fight but I could use some clarification....I looked at my grease tube last night...It says "NLGI" 2.....I was reading the post here and they are saying "SGLI"......I went on Autozones web sight and most don't have the number under description/details but those that DO have "NLGI"......Are these two different greases NLGI 2 and SGLI 2 ? I don't want to use the wrong grease, especially on the king pin bearings. While searching ON line (GOOGLE) the "SGLI" is mainly sending me to this form, NLGI gets me a LOT of lube sights....... I never paid much attention to grease other than "Recommended for disk brakes" or NOT recommended for disk brakes". ....HELP.......

[captw]

I have posted previously on this subject, but will again...John Deere Corn Head Grease...NGLI 0 ...I use it in the knuckles, and steering boxes of both my M38 and M37...W

[wesk]

The S in _GLI is my typo.!!

[HULLROAD]

Thank You Wes
Well, That right their explains a LOT
By the way. I live about as far south as you can get and still be a Michigander. In fact I only live about 25 miles north of the Willys Overland/Jeep plant in Toledo, Well were it was anyway, still can't believe they tore down such a land mark. I remember riding by as a kid and seeing the Jeeps on the roof. My favorite was the 76 model done up with the stars and stripes for the bicentennial. I figured it would not work out good for Jeep when the Germans (Daimler Chrysler) got a hold of it. Theirs got to be SOME bad feelings left over from that. Oh well so much for memory lane

[skyjeep50]

Thanks wesk and captw for your posts. I'm going to the "Green" store to get me some grease - if its green, it has to be good.
Found the comparison chart below on NLGI consistencies, puts it into perspective. I'm looking for something in the "apple sauce" to "brown mustard" catagory! A manufactured grease would be better than a homemade pudding. I couldn't find a local supplier for thin greases (auto supply stores) but didn't think about ag equipment suppliers. I've worked on my share of green and red farm machinery before but didn't make the connection. Like Bill Engvall says - "Here's your sign".

http://en.wikipedia.org/wiki/NLGI_consistency_number

[wesk]

What about orange??

[HULLROAD]

Skyjeep...Thanks....I found that while googling also...My jeep had the "frozen yogurt" in it when I took it apart. Stuff was also real sticky like trying to clean up uncured epoxy. Had to scoop it out and then thin it down with kerosene to get it cleaned out. Only thing that saved my axle joints was the fact that they did not turn often with the locking hubs. Might be why the seals went though.
YES...Ag and heavy equipment has got ALL kinds of fancy lube. Only limited by one's imagination ...and wallet.

[skyjeep50]

wesk - never orange, just johnny pop-pop, inner-trash-enal, messy fergison, white (silver), fix-or-replace-daily blue (Ford) and a little yellow (New Zealand and Minneapolis-Moline). Never had the opportunity to screw up something with orange paint.

[RICKG]

wesk - never orange, just johnny pop-pop, inner-trash-enal, messy fergison, white (silver), fix-or-replace-daily blue (Ford) and a little yellow (New Zealand and Minneapolis-Moline). Never had the opportunity to screw up something with orange paint.

We always allowed that the Red, Orange and Blue iron did all the
work while the Green/Yellow JD tractors hid cammo'd in the weeds and
sunflowers

[captw]

you're welcome Skyjeep50...I'm sure you know, but I'll post in case others are wondering...I used black pipe bushing reducers to drop from , I think 3/4" NPT, down to 1/8"NPT so that I could use a a zerk fitting and pump the grease in, for both the steering box and knuckles...use caution at the knuckles, as you don't want to push the grease into the axle tubes and have it eventually mix with the gear lube in the differential!!...W