Info needed: 1967 M38A1 Lubrication?

[rob love]

If the temp is not overheating, then there is no problem with your thermostat. Most likely it is one of two things. The most likely is that you are simply overfilling the radiator. Unlike modern vehicles, there is no radiator overflow. So if you have overfilled the rad, as it expands, there will be some overflow. It should find it's own level, which will be just above the core of the radiator.

The other is that you could have the beginning of a head gasket leak. Try this: Open and close the rad cap (engine cold) so there is zero pressure in the radiator. Start the jeep cold and run it for 30 seconds to a minute. Shut it off and open the rad cap. If there is pressure there, then you need the engine gasket replaced. You will also observe that the coolant will turn a muddy brown instead of it's usual bright green. Don't bother with the gasket sealing gimmicks....replace the gasket. It only takes a couple hours and you will be good for another 30 years. I had to recently do this on the parade Jeep here in Shilo. Only 2300 original miles, but the coolant got acidic over the years and the gasket failed along with some of the aluminum heater hose fittings.

Wrt what thermostat to use if you did need one, if you are going to use your Jeep in the cooler months and want your heater, then go with a 180. Otherwise, a 160 is fine. Note that these temps are the closing temps of the thermostat. Some of the lesser brands of thermostat will not open until 240, which is fine for modern automobiles with 15 pound pressure systems, but is too high for the 7 lb system of a Jeep. In the old days, a Cdn tire thermostat would give me grief while a Ford motorcraft thermostat worked just fine. In all honesty, I have not replaced a thermostat in a lot of years, so you may be fine with a NAPA or Cdn tire thermostat these days. The thermostat is common to Ford and Dodges from the last 60 years so is easy enough to find.

Back to your steering: The drag link is adjustable, so unless you know you need the pitman arm because the ball has been worn, then you can just remove the cotter pins on each end of the drag link, and tighten up the sockets a bit. Not enough to bind, but enough to remove the play. For the bellcrank, you just need two torrington B188 bearings, and can flip the sleeve over to run the bearings on fresh surfaces.

The safety check may not catch the kingpin bearings. In this modern age of sealed disposable balljoints, most mechanics will not look for the worn bearings of the kingpins. They certainly would not be doing the test I indicated of removing the tires and tie rods, and turning the knuckles.

[Les Kovacs]

Hi Rob,

Thanks for all the valuable info/tidbits....firstly, yes, the rad still pukes fluid but its still well above the core. I have run the engine for about 30kms since I bought it a few days ago and there is still no oil droplets in the rad fluid or malted milk fluid around the inside of the oil filler or on the dip stick. The temp gauge always reads about 120-140 and no more....is this normal?....or do you think its busted? I will test as per your suggestion by running for 1 min and then cracking open the rad cap and looking for pressure.

As per the drag link....I did notice that the ends have cross marks as if they can be adjusted. I Also noticed that the drag link has a repair kit on it already. It steers OK but again, if I hit a pothole at about 20-30 kms the steering wheel shakes for a split second then settles down.

Canadian tire has only 80-90 gear oil al GL4 or 5..cannot find GL 3....had to top up the front & rear diffs as they were well below filler lip. Have not look at the trans or transfer yet but they are leaking....hopefully its only at the drain plugs. Oil pan gasket leaked....I put a socket to it....all the bolts were only finger tight....tightened to about 10-20 ft. lbs....appears to have stopped leak.

I sincerely thank you for all the info.....if you do not mind, I would love to use you as a resource while trying to make a reliable runner out of the jeep.

PS...If Shilo is the armpit of the world...then Bangui (Central African Republic) is the toilet of the world.

Regards,

les

[rob love]

The parade Jeep I worked on did not have any water in the oil. Remember that you have 120 psi in a cylinder, and only 7 pounds in a radiator, so if the head gasket leak is marginal, it may not show in the oil.

Yes, GL3 is hard to find. But it is out there.

Always happy to share my opinions, even when they are not asked for.

[David Herbert]

Any gear oil with 'EP' in its designation, which includes GL4 &5 is rather more than 'hard on yellow metal' components. The EP additives get into the molecular structure of the surface of the component and prizes it apart on a microscopic level. A bit like ivy growing on a stone wall pulls the mortar out and eventually the wall crumbles. The result of this is that any wearing surface falls apart VERY quickly. I have seen 1mm wear in 1 hour of use on a not terribly loaded plain bronze bearing because of this. This is a serious problem if you get it wrong !

There are plenty of non-automotive uses for non EP gear oils (such as worm reduction gearboxes on electric motors on industrial machinery) so cast your net a bit wider than the local auto parts outlet. What you need is out there.

With regard to the viscosity of engine oil, check out the owners manual of your modern car, which I suggest should have more specific needs than a 50 year old MV. You will see that there is a huge range of acceptable grades of oil for a particular climate (more so in the UK than the more extreme summer/winter variation in Canada) so within limits you do have some latitude. Synthetic oil is much more resistant to breakdown than mineral oils but that is not a great advantage to MVs as you probably are not trying to get 16000miles between oil changes (I hope).

David

[David Dunlop]

Just a thought on the wheel wobble. Check that the wheels are all balanced and don't assume that the presence of any weights on them means they are. Paved roads can wear older ND tyres rather more quickly than one might expect.

David

[maple_leaf_eh]

Originally Posted by rob love

...

... It only takes a couple hours and you will be good for another 30 years. I had to recently do this on the parade Jeep here in Shilo. Only 2300 original miles, but the coolant got acidic over the years and the gasket failed along with some of the aluminum heater hose fittings. ...

...

Apparently there is another 1953 1/4-ton ceremonial Jeep in 25 CFSD Longue Pointe. Out of curiosity, what is the ERN and CFR of Shilo's? It would be interesting to see whether there are any others in the system.

[rob love]

It is held as an artifact rather than a CFR'd piece of equipment. ERN forany CDN3 will be the same, it is the ECC that will be different. There was a specific ECC for the ceremonial/VIP trucks.

Les: Drain your rad so you are just slightly above the rad core, then take it for a drive and see if it is puking a/f. You may have nothing more than a overfilled radiator.

[Les Kovacs]

Thanks to all for your valuable input!

1. To Rob....the jeep passed inspection this AM and I got plated! It was a real crock....they never even took any wheels off to check for brake shoe wear!

2. I will have the front wheel balanced next week.

3. To Rob.....I tried the rad test.....started engine and ran for 1 min....appears to be no pressure when rad cover taken off.

4. Right now the rad fluid is very bright green and about 2 inches above the core.....however, the rad appears to have stopped puking fluid onto the front axle....for now!

6. Rad temp as per gauge goes to about 130-140 after 20 min drive with 2 aboard...is this a normal range?

7. As per #6.....the temp gauge get slightly fogged up in the center after about 3-5min.....is this normal?

8. Changed both diff fluids with 80W90 Motomaster GL4-5.....rear diff fluid was so discoloured (malted milk) that it may have ingested H2O at one time or another. I will change rear fluid in another 1-2 weeks.

Rob....please respond to #6 if time permits.....not sure what temp should be
when run for 20 min.

Still looking for trans oil.....I hear that Redline makes a 75W-90 that does not affect "yellow metals"

Regards for now,

les

[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