Joined: Mar 13, 2006 Posts: 1079 Location: Richburg, SC
Posted: Wed Sep 26, 2012 8:31 am Post subject:
Uh oh - there's that can of worms again!
Seriously though, there are 2 schools of thought there: oil or a grease/oil G.O. is better, but the next person might tell you the mixture is better.
The rear doesn't have knuckle oil - or a knuckle at all. Its bearings are lubed by the differential oil.
I used a mix of 140w G.O. and wheel bearing grease - makes like a 2-300w G.O. - barely moving grease. Just remember to grese and adjust your upper kingpin bearings before you use this method - I had to replace mine because there was "cake" type grease in my hubs (in other words, hadn't been serviced in many years!).
The knuckle design was not meant to carry a liquid grease. The original Army plan called for frequent disassembly and hand packing with #2 chassis grease. This is still the most reliable lubrication plan. Problem is folks today are raised on electronic ignition and permanent lubed joints and they abhor this repetative lubrication program so they have improvised over the years with various gooey contraptions. The knuckle spheres must be in excellent condition (smooth as a baby's bottom) with quality seals and seal retainers or this gooey mess ends up on the floor.
If you are in very cold climates the gooey stuff lets the axle turn easier. Hot climates you are better off with any quality #2 sgli grease. In either case you must open the knuckle up and cleaned the steering pivot bearings and repack them with a #2 sgli grease at least every 6000 miles. Don't let that grease get to old on the calander either. About 4 years max. The gooey stuff will not sling onto these pivot bearings. They must be cleaned and packed by hand periodically.
The choices for gooey stuff are endless and everyone who uses a mixture will swear by it just as they do on Marvel Mystery oil. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Posted: Thu Sep 27, 2012 7:24 am Post subject: front axle joint lube
I use John Deere Corn Head grease in the knuckles on both my M38 and M37, and in both steering boxes...the grease in NLGI 0, and is for use in low speed high impact applications...in your question, though, you say fron t and rear "hubs"...if you mean the lubing the bearings in the hubs, use wheel bearing grease...W _________________ Wilf Alexander
R.R.#1 Bailieboro, Ontario
Canada
1952 M38CDN F-100822 CAR 52-31153
1953 M100CDN 1104 CAR 53-71157
1953 M37CDN
M274A4
(2) 1945 Dodge D3/4 WP/APT
I believe if you look closely the rear axle has a plug or zerk at the outboard end through which you inject SGLI #2 with a hand grease gun being careful not to over service and push grease through the seal to the brakes. This is shown in the TM's. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Posted: Thu Sep 27, 2012 10:16 am Post subject: zerks
Hi Wes...I don't know if it was a change to save money, or not, but on my M38CDN, the spring loaded vents are on top, but where the zerks would go, there are threaded plugs...W _________________ Wilf Alexander
R.R.#1 Bailieboro, Ontario
Canada
1952 M38CDN F-100822 CAR 52-31153
1953 M100CDN 1104 CAR 53-71157
1953 M37CDN
M274A4
(2) 1945 Dodge D3/4 WP/APT
The Army had the zerks removed because their junior mechanics were overgreasing them. Just remove the plugs install a zerk and grease only one to two pumps at 6000 miles then remove, clean and hand pack at 12000 miles. The earlier M38 TM9-804 showed the fitting. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Posted: Thu Sep 27, 2012 10:48 am Post subject: zerks
Wes...since I had to replace all the bearings in the rear axle due to suspected water in the axle(even the pinion and carrier bearings had to be replaced), I did just that...the zerks for the outboard bearings get a couple of shots once a year...W _________________ Wilf Alexander
R.R.#1 Bailieboro, Ontario
Canada
1952 M38CDN F-100822 CAR 52-31153
1953 M100CDN 1104 CAR 53-71157
1953 M37CDN
M274A4
(2) 1945 Dodge D3/4 WP/APT
Joined: Mar 13, 2006 Posts: 1079 Location: Richburg, SC
Posted: Thu Sep 27, 2012 12:47 pm Post subject:
Man, I got that one wrong! I forgot about the inner axle seals - no G.O. can get to the bearings.
Quote:
Just remove the plugs install a zerk and grease only one to two pumps at 6000 miles then remove, clean and hand pack at 12000 miles. The earlier M38 TM9-804 showed the fitting.
I guess it might be time to do mine - it is AT LEAST 15 years overdue! Maybe I'll pump a little grease in there and leave the hand packing for a late fall project! _________________ Matt
1953 M38a1
1964 USMC M38a1
'51 USMC M100 trailer, '54 M100 trailer, '90 M101a1 trailer
Http://wilfreeman.wordpress.com (M38a1 build blog)
http://m38a1usmc.wordpress.com (USMC M38a1 rebuild blog)
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