M38 issue update
- Stiknruddr
- Contributor

- Posts: 54
- Joined: Thu Jul 27, 2017 6:00 pm
M38 issue update
I’ve made several posts about my M38 engine issues and thought I’d update. As to carb issues YS637 never could get the first one to operate. Got a second core, rebuilt carb issue solved. Buuut....then found it was still missing and sure enough those “new” plug wires? One was bad. Then still a ignition stutter when not under a load. Quite a bit of play in the Autolite distributor so bought a “new” one. Junk. Just rebuilt the Autolite runs sweet. I can’t say enough about Willy’s Distributors had everything to rebuild the Autolite which is solid. Thanks for all who contributed to my issues. Now...off to the MEP 803 generator. Winter coming. Neal
- Stiknruddr
- Contributor

- Posts: 54
- Joined: Thu Jul 27, 2017 6:00 pm
Oh and...
Increased the timing to 8-10 degrees runs spunky with 89 octane gas.
- Dmk67
- Member
- Posts: 18
- Joined: Thu Jul 20, 2017 6:00 pm
- Location: Rhode Island
Thank you for the update! I really enjoy hearing not only the issue , symptoms,etc ( as I have plenty of them too!) but the resolution to issues, these updates really help to track down similar issues as they inevitably crop up!
Thanks again,
Dave
Thanks again,
Dave
Dave
Rhode Island
Willy’s MC / M38
Build date August of 1951
S/N MC 31118
Proudly helping her to stay active in her retired years ...
Rhode Island
Willy’s MC / M38
Build date August of 1951
S/N MC 31118
Proudly helping her to stay active in her retired years ...
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RonD2
- Jeep Legend

- Posts: 2070
- Joined: Wed Oct 01, 2014 6:00 pm
- Location: South Carolina, Dorchester County
- Stiknruddr
- Contributor

- Posts: 54
- Joined: Thu Jul 27, 2017 6:00 pm
Wiring
Another post I made was concerning wiring mine was shot. I found a nos M170 harness shortened the rear part and converted to a 12v single wire alternator dual pulley. I ran a 12ga wire dedicated to powering the 3 lever light switch and a separate wire with circuit breaker for ignition. I just replaced the pin in the light plug with the new wire. I removed the 20amp circuit breaker from the 3 lever light switch. Fabricated the front headlight harness from surplus harnesses and connectors from Saturn Surplus. Used 2 left rear lights to have dual brake lights. Bulbs from a pin ball supplier in CA. All can be put back to 28v in a day.
- Stiknruddr
- Contributor

- Posts: 54
- Joined: Thu Jul 27, 2017 6:00 pm
Oil pressure
The block in my M38 is civilian sn but was new or overhauled a long time ago. Standard bore looks new inside. Had low oil pressure. Pulled the relief valve, broken spring. Shimmed it running 40wt here in the south now 20# + when hot at cruise. 10-15 at idle. Leaking trans grease out the bell housing pulling the trans Tuesday date tag says 7/15/51 and the Jeep was delivered in 08/51 so probably original to the Jeep.
- dpcd67
- Active Member

- Posts: 187
- Joined: Thu Nov 24, 2016 6:00 pm
- Location: Iowa
I put a new Melling oil pump in and instantly got 55 pounds; from 30 with the original aluminum pump.
M38 23100 June 51
M38 34523 Sep 51
M606/CJ3B 1964 Kaiser 57348 118458
M37B1 1963
Willys MB 1944
Ford GPW 1942
Dodge WC63 1943
Dodge Power Wagon WM300 1967
Plymouth Barracuda, 1973, 340 4 barrel
All ground up restored by me.
Lots of others.
M38 34523 Sep 51
M606/CJ3B 1964 Kaiser 57348 118458
M37B1 1963
Willys MB 1944
Ford GPW 1942
Dodge WC63 1943
Dodge Power Wagon WM300 1967
Plymouth Barracuda, 1973, 340 4 barrel
All ground up restored by me.
Lots of others.