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I am in the process of rebuilding the front axle of an M38A1. I discovered that the (6) 3/8" bolts that hold the knuckle flange and backing plate together had been inserted through the inside of the knuckle and secured with a nut on the outside.

The threads on the knuckle will no longer hold a 3/8" X 24 bolt. There seems to be enough metal to re-bore and tap to 7/16" X 20. This would also mean that the flange and backing plate holes would also have to be drilled to 7/16".

This would sure seem to save a lot of time, money and effort.

Any thoughts?

Thanks,

Trip

Just a reminder that the original bolts would have been hardened. I replaced the knuckles on my GPW because one of the previous owners had stripped some of the threads. I was told about the hardened bolts after I had fitted standard ones from the hardware shop. I did not want to strip the hubs/bearings etc again because I don't intend to do any serious off-roading. I checked them recently when I changed the brake shoes - they looked ok.
Graeme

Have you thought about using a hellicoil thread repair?

The PO of my M38 had drilled out a few of the holes and threaded them for larger bolts. It made installation and removal a PIA because the new bolts didnt clear something (I'm going from memory). So I got a donor knuckle with good original size thread and installed it when I did the kingpins.
Frankly you don't want to take any chances with those knuckles. Failure is bad.
Here is an article if you are interested in working the jeep a little hard: http://www.earlycj5.com/technical/steer ... d-upgrade/

Regarding Helicoils or threaded inserts, you will want to check with the manufacturer regarding strength of the installed setup.
Staying on the safe side is the best thing to do with the knuckle bolts.

Tom

I.d go along with the finding of a donor knukle or evan a new one if you are rebuilding it I wouldnt cut corners, also check to see if the tie rod holes are rounded out found that out after I had them back togeather.
Scott out

I just bought an 52 M38 and I went to fill everything with gear oil, and was fine until I got to the front steering knuckles, I added 140wt oil to the knuckles and it all leaked out over night, what should I do?

Leaking knuckles - they are supposed to be filled with grease according to the military maintenance lubrication chart. Some people use oil but unless your seals are tight, the oil will find a way out. Civilian jeeps used a light, semi-solid flowable grease which may be not avialable anymore. Again, some people advocate making a "pudding" of half 100W oil and half chassis grease - won't leak out but will sling and provide some lube to the king bearings. I used some of this pudding in my M38A1's steering gear which won't hold lube oil anymore (the rebuild is coming soon) and it worked fine.

Be very selective about the path you take with this repair. Failure of this structure would be catastrophic. It is a direct safety item.
Drilling to a larger bolt may work but bubba did that to my M38 on one stud and there was interference with the nut so it never was correctly torqued.
Here is an upgrade for studs that has been reasonably thought out. A search for knuckle stud replacements will also bring up other tested repairs:
http://www.earlycj5.com/technical/steer ... d-upgrade/

If you look around you may find a good used inexpensive knuckle that is not stripped out. The structure of the original setup is safe and solid for how most on this board are driving their M38's. Upgrade if you are going to beat on the jeep.
I was lucky to find a pair of good knuckles just for the asking and labor of removing them.

Tom

The military manuals all spec'd GP-0 winter and GP-1 summer chassis lube until the 50's when they switched to GAA grease. The CJ's mad the switch late 50's early 60's to . This was checked and topped every 1000 miles and cleaned and repacked every 6000 miles. Very aggressive maintenance scheduling.

The CJ early spec'd Universal Joint grease 0 winter and 1 summer. Check at 1000 and change at 12000.

The later CJ manual starting in the 60's listed GL3 140 WT and service at 2000 and replace at 12000.

Try to keep formost in your mind that the specified lubricants from the 1940 thru 1960 charts are no longer produced. This means you must choose from what is available today. That choice will have to consider the condition of your hubs, the spherical surface condition and the seal condition.

The rougher the condition of your hubs the heavier viscosity oil or grease you must use. 140 gear oil GL3 or equivalent will work in very good hubs. It is also more desirable in the northern latitudes where they become harder to roll in the winter. On the rough end of the spectrum of choices is standard chassis lube in seasonal weights or Ford 600 weight gear oil.


Finally as mentioned above if you have ever experienced a failure of any critical front suspension component that forces you to loose directional control you will never again take cheap or short cut repairs.