Info needed: 1967 M38A1 Lubrication?

[maple_leaf_eh]

If your HMV passed one inspection, don't let the licence lapse. It will only get harder from here forward.

[rob love]

130-140 is a little low, normal would be in the 160 to 180 range. Normally, if the jeep had the heater, it should have had a 180 thermostat, but you don't know what others have put in there for a thermostat over it's decades of civilian service. Remember the gauge and sending unit are likely almost 50 years old, so it would not be inconceivable it could be out 30° or so. The moisture in the gauge is not ideal, since they were a sealed unit. You can either live with that or replace it. I suppose you could run the Jeep and check the engine temp at the upper core of the rad with a digital thermometer of some kind.

It sounds to me like your radiator may have been simply overfull. The Jeep will find it's own level.

Re the rear fluid, another good indicator that you need to check the rear bearings. If the Jeep was deep enough to ingest water into the diff, then it was deep enough to contaminate the rear wheel bearings.

[Les Kovacs]

Hi Rob....I have driven the jeep only for 10-15min intervals and then slowly with no high speed and with only 1 person aboard.....maybe 130-140 is correct but I doubt it as it is more than likely the original thermostat.

Both axels have now been drained and refilled with motomaster 80w-90 Gl4-5.

I have found the 1/4 inch plugs at the rear wheels....the overflow plug works-plungers move freely....all I need to is buy 1/4 in zerks from CT.

I have also purchased 3 liters of Redline 75w-90 MT-90 trans oil to replace oil in trans & transfer case....this oil is GL1, 2 & 3 rated....its a full synthetic so I hope it does not puke out too much at $21 CDN a bottle.

Again, thanks for all the tidbits.....they are priceless.....If you have anymore maintenance items for this novice M38A1 owner...please do not hesitate.

Cheers,

les

[rob love]

The Cdn Army had those two zerk fittings removed as they did not properly grease the rear wheel bearings. As well, if you over-do pumping grease into there, it has to go somewhere. I suppose putting grease into there is better than nothing, but ideally you remove the axles, clean and inspect the bearings, I go with new inner and outer axle seals (since they are fairly cheap) and set the axle preload/endplay at the same time. Then you can drive with confidence. But it is a big job for a novice.

[Les Kovacs]

Hi Rob.....I have another issue....I have downloaded two M38A1 Spec sheets (one US military and the other from Kaiser) from the internet..... they both state that the front/rear axle oil capacity is 2.5 qts or 2.4 liters......however, the 1967 M38A1 CDN2 Canadian DOD manual that came with the jeep states that the front/rear axle capacity is both 1.0 qts or about 1.0 liters.....which one is correct?

Thanks,

les

[rob love]

Well you made me have to stand up and reach onto the book shelf over the computer.

My operator manual shows 1 quart. That will be imperial so bigger than a US quart or a liter.

Quite frankly, fill the differential until it is one knuckle below the filler hole. Same goes for transmission and transfer case. If you reach your finger into the hole and bend the first digit down, it should just be picking up the oil. Also, service the little breather valve on top of the diffs. You simply give it a couple twists to dislodge any dirt that has attached itself to the oil vapour and can plug up the valve.

[Les Kovacs]

Rob....sorry for making you reach over the computer for the manual.....but clearly, the CDN manual states 1.0 quart for both diffs and both of the US spec docs that I have clearly show 2.5 quarts per axle....I will go with 1 quart plus and then bend finger one knuckle and touch oil.

I am now working on transmission.....both the CDN & US manuals for the 67 M38A1 show 1.0 quart of oil.....I drained out 1.6 liters....maybe that is why it was rust proofing the frame with its leaking.

Thanks....

les