Exhaust Manifold Studs

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cobra5
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Exhaust Manifold Studs

Post by cobra5 »

I need to know if the studs go into the water jacket. I’m getting coolant leaking out the nuts at #1 &#4. I’m planning on pulling the valve cover and checking torque on the head bolts. This engine was rebuilt by the last owner. I do not know how long ago or how many miles he put on it. The engine looks like it was rebuilt yesterday. I can’t ask the owner because I bought it from his estate and they have no idea.
1951 M37 WOW, 1953 M37 WOW, 1954 M37 WOW, 1953 M38-A1, 1954 M38-A1, 1964 M151-A1, 1967 M151-A1, 1968 M151-A1, 1978 M151-A2, 1989 M35A2C, 1965 M416, 1966 M416, 1967 M416
MSgt, USAF Retired 1/84-10/05
RonD2
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Post by RonD2 »

Paragraph 118 on page 132 of the F134 Engine TM9-8015-1 says yes.

That manual is free in the downloads section.

Good luck!
Ron D.
1951 M38 Unknown Serial Number
1951 M100 Dunbar Kapple 01169903 dod 5-51

“The only good sports car that America ever made was the Jeep."
--- Enzo Ferrari

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dpcd67
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Post by dpcd67 »

If he had put permatex on the studs before he installed them it wouldn't leak.
If it was mine, I would pull them and do that.
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.
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cobra5
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Post by cobra5 »

RonD2 wrote:Paragraph 118 on page 132 of the F134 Engine TM9-8015-1 says yes.

That manual is free in the downloads section.

Good luck!
It took me a while to find them because they aren't in the download section under M38/M38A1 file section. I skipped right past the section that states, "manuals" because I thought they were all misc. manuals not related to the M38A1. Anyway thanks for the direction and now I will be spending the day downloading the rest of them.
1951 M37 WOW, 1953 M37 WOW, 1954 M37 WOW, 1953 M38-A1, 1954 M38-A1, 1964 M151-A1, 1967 M151-A1, 1968 M151-A1, 1978 M151-A2, 1989 M35A2C, 1965 M416, 1966 M416, 1967 M416
MSgt, USAF Retired 1/84-10/05
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cobra5
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Post by cobra5 »

dpcd67 wrote:If he had put permatex on the studs before he installed them it wouldn't leak.
If it was mine, I would pull them and do that.
I read several threads about the permatex so I will go over those again and find the one everyone recommends. Thanks for the heads up.
1951 M37 WOW, 1953 M37 WOW, 1954 M37 WOW, 1953 M38-A1, 1954 M38-A1, 1964 M151-A1, 1967 M151-A1, 1968 M151-A1, 1978 M151-A2, 1989 M35A2C, 1965 M416, 1966 M416, 1967 M416
MSgt, USAF Retired 1/84-10/05
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jake138
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Post by jake138 »

This is what I used, it's a white paste that looks like liquid pipe tape.

https://www.permatex.com/products/threa ... th-ptfe-2/
Jake, Central CT
51 M38 s/n 35627
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cobra5
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Post by cobra5 »

I pulled the studs and they were bare. Also discovered that two studs were missing. So is there a civilian part number for the exhaust studs and gasket? I’m going to look in the parts book and see if it calls out the dimensions of the studs.
1951 M37 WOW, 1953 M37 WOW, 1954 M37 WOW, 1953 M38-A1, 1954 M38-A1, 1964 M151-A1, 1967 M151-A1, 1968 M151-A1, 1978 M151-A2, 1989 M35A2C, 1965 M416, 1966 M416, 1967 M416
MSgt, USAF Retired 1/84-10/05
RonD2
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Post by RonD2 »

Hi Cobra,
Wow. It's hard to imagine that coolant wasn't also gushing out of those missing <2 out of 5 total> stud holes? What's with that?

I didn't look in the manual for you this time, but many of the reliable and venerable vendors of our military jeep parts can hook you up with the proper studs and gaskets......MWM, RFJP, BMJP, QTM, and AJP come to mind.

Those are very common parts and relatively inexpensive. Might even be able to buy them at your local auto parts store. Tell them it's for a Willys F134 motor.

Good luck!
Ron D.
1951 M38 Unknown Serial Number
1951 M100 Dunbar Kapple 01169903 dod 5-51

“The only good sports car that America ever made was the Jeep."
--- Enzo Ferrari

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cobra5
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Post by cobra5 »

RonD2 wrote:Hi Cobra,
Wow. It's hard to imagine that coolant wasn't also gushing out of those missing <2 out of 5 total> stud holes? What's with that?

I didn't look in the manual for you this time, but many of the reliable and venerable vendors of our military jeep parts can hook you up with the proper studs and gaskets......MWM, RFJP, BMJP, QTM, and AJP come to mind.

Those are very common parts and relatively inexpensive. Might even be able to buy them at your local auto parts store. Tell them it's for a Willys F134 motor.

Good luck!
RonD2,

I checked the manual and I was incorrect about the missing studs. The holes I thought should have studs are actually extra threaded holes in the block. The front hole is for the fording cable bracket. Not sure about the aft hole. I feel better knowing that the manifold is probably okay and not warped as it would have been if studs were missing. Another fun fact is that the studs had no rust on them so this engine can't be too old of a build. I called John at MWM to get parts coming my way.
1951 M37 WOW, 1953 M37 WOW, 1954 M37 WOW, 1953 M38-A1, 1954 M38-A1, 1964 M151-A1, 1967 M151-A1, 1968 M151-A1, 1978 M151-A2, 1989 M35A2C, 1965 M416, 1966 M416, 1967 M416
MSgt, USAF Retired 1/84-10/05
RonD2
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Post by RonD2 »

Hi Cobra,
Please close the loop and let us know how it worked out for you. Too many posts get left hanging.....

Good luck!
Ron D.
1951 M38 Unknown Serial Number
1951 M100 Dunbar Kapple 01169903 dod 5-51

“The only good sports car that America ever made was the Jeep."
--- Enzo Ferrari

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cobra5
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Post by cobra5 »

RonD2 wrote:Hi Cobra,
Please close the loop and let us know how it worked out for you. Too many posts get left hanging.....

Good luck!
Received my parts the other day but haven't had time to work on it. I will post the outcome when I get the issue addressed.
1951 M37 WOW, 1953 M37 WOW, 1954 M37 WOW, 1953 M38-A1, 1954 M38-A1, 1964 M151-A1, 1967 M151-A1, 1968 M151-A1, 1978 M151-A2, 1989 M35A2C, 1965 M416, 1966 M416, 1967 M416
MSgt, USAF Retired 1/84-10/05
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cobra5
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Post by cobra5 »

Ok I finally got around to working on the jeep again. First off, my concern about the missing studs was an error on my part. I'm use to seeing two studs per exhaust ports on heads. One of the two extra holes in the head are for mounting a bracket for the fording system. The other hole could be from manufacturing process of the head? Anyway, the one thing I discovered is that the exhaust bolt kit that I received did not have long enough studs for the outer most studs. I when to the local parts house and bought the correct length. I used the recommended Permatex to seal all the studs. While I was chasing this coolant leak I figured I would pull the valve cover and torque check the head bolts. I found two bolts that were not in torque specs. Everything is back together and now all I have to do is fill with coolant and check to see if my leak is fixed. This will happen later this week when I get some time. I also replaced the ignition wires because I had one where the metal braided covering was shot. I will report back once I get it running to let everyone know if the leak had been fixed.
1951 M37 WOW, 1953 M37 WOW, 1954 M37 WOW, 1953 M38-A1, 1954 M38-A1, 1964 M151-A1, 1967 M151-A1, 1968 M151-A1, 1978 M151-A2, 1989 M35A2C, 1965 M416, 1966 M416, 1967 M416
MSgt, USAF Retired 1/84-10/05
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cobra5
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Post by cobra5 »

Well I got around to filling the radiator and starting it up. I didn’t notice any coolant leaks and just to be sure, I let it sit over night and checked for a puddle under it. Happy to report all is well and she is up and running. I did notice the oil gauge was low at idle but pressure would increase with rpm. I’m going to change the oil since this thing was rebuilt and I have no history as to when the rebuild happened. I don’t know if the oil was ever changed after. The oil is clean like just poured out of the bottle. So that’s my plan and then I will hook up a mechanic gauge and see if I’m getting 5psi at idle.
1951 M37 WOW, 1953 M37 WOW, 1954 M37 WOW, 1953 M38-A1, 1954 M38-A1, 1964 M151-A1, 1967 M151-A1, 1968 M151-A1, 1978 M151-A2, 1989 M35A2C, 1965 M416, 1966 M416, 1967 M416
MSgt, USAF Retired 1/84-10/05
RonD2
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Post by RonD2 »

Glad to hear that!

Recommend using motor oil with some ZDDP in it. Lots of posts about it, like this one: http://willysmjeeps.com/v2/modules.php? ... light=zddp

Good luck!
Ron D.
1951 M38 Unknown Serial Number
1951 M100 Dunbar Kapple 01169903 dod 5-51

“The only good sports car that America ever made was the Jeep."
--- Enzo Ferrari

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cobra5
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Post by cobra5 »

I'll be using Rotella 15W40
1951 M37 WOW, 1953 M37 WOW, 1954 M37 WOW, 1953 M38-A1, 1954 M38-A1, 1964 M151-A1, 1967 M151-A1, 1968 M151-A1, 1978 M151-A2, 1989 M35A2C, 1965 M416, 1966 M416, 1967 M416
MSgt, USAF Retired 1/84-10/05
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