IMPORTANT M-38/M-38A1 REMINDER

1952 - 1968, M38A1, M170, questions, discussions, regarding anything related to the M38a1 series.
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IMPORTANT M-38/M-38A1 REMINDER

Post by Joe Gopan » Mon Aug 09, 2010 10:52 am

Do not ignore your rear wheel bearings on these Jeeps, they were originally lubed with GAA, if you have some that is fine, if not use a good grade of current chassis grease. The Army had a Bulletin to remove the fittings near the backing plates and replace with pipe plugs. The rear wheel bearings do require service at least every 12,000 miles. Install the grease fittings and very slowly with a hand pump grease gun pump grease untill the little spring loaded valve located atop the axle tube next to the backing plate starts to lift and stop when grease appears. To overdo it may force grease past the outer seal at the rear hub and contaminate your brake shoes. If they have not been serviced for a while, 7-10 pumps will usually do it. (The CJ Jeeps have grease fittings also, but just have drilled holes atop the tube and do not have pressure relief fittings.
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Re: IMPORTANT M-38/M-38A1 REMINDER

Post by Joe Gopan » Thu Oct 13, 2011 10:03 am

It's time to remind you again. :wink:
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Re: IMPORTANT M-38/M-38A1 REMINDER

Post by Cuz » Thu Oct 13, 2011 6:50 pm

http://www.g503.com/forums/viewtopic.php?f=11&t=114661" onclick="window.open(this.href);return false; ??????
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Re: IMPORTANT M-38/M-38A1 REMINDER

Post by Joe Gopan » Fri Oct 14, 2011 5:02 am

The rear wheel bearings on the M-38/M-38a1 are not an item to forget. burned out rear wheel bearings and ruined axle shafts are a reality.
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HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
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Re: IMPORTANT M-38/M-38A1 REMINDER

Post by Lolo777 » Fri Oct 14, 2011 6:25 am

Thank you very much Ben but when do you know is enought grease while you are putting in into????
Kind regares from Granada, spain.
M38a1 MD Nekaf 1956.
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Re: IMPORTANT M-38/M-38A1 REMINDER

Post by Joe Gopan » Fri Oct 14, 2011 7:31 am

It is very easy to tell, scroll back two or three replys above and follow the advice. One must pump very slowly or risk blowing out the outer wheel seal on the outside of the backing plate. Stop when the spring loaded relief valve starts to rise. I have NOS Relief valves available if yours is damaged. The Schedule calls for 12,000 miles, that would take me two or three years now. I make it a point to give it a few easy shots of GAA every two or three years . I have operated my present M-38A1 since 1975 with no lubrication problems or Oil Seal failures in the running gear.
2011 MVPA PIONEER AWARD - MVPA #1064
HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
LIFE MEMBER AM LEGION-40/8-DAV
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Re: IMPORTANT M-38/M-38A1 REMINDER

Post by Joe Gopan » Mon Jan 02, 2012 8:31 pm

This service cannot be stressed enough times.
It also applies to the CJJeeps with semi-floating rear axles, although the CJ's do not have the pressure relief valve.
2011 MVPA PIONEER AWARD - MVPA #1064
HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
LIFE MEMBER AM LEGION-40/8-DAV
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COL. BRUNO BROOKS (ARMY MOTORS) IS MY HERO

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Re: IMPORTANT M-38/M-38A1 REMINDER

Post by Joe Gopan » Sun Sep 27, 2015 9:51 am

This is very important to M-38 and M-38A1 owners, it can't be stressed enough.
2011 MVPA PIONEER AWARD - MVPA #1064
HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
LIFE MEMBER AM LEGION-40/8-DAV
7 MIL SPEC MAINTAINED MV'S
COL. BRUNO BROOKS (ARMY MOTORS) IS MY HERO

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Re: IMPORTANT M-38/M-38A1 REMINDER

Post by Joe Gopan » Sat Apr 23, 2016 5:05 am

Just a reminder for this much ignored feature.
2011 MVPA PIONEER AWARD - MVPA #1064
HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
LIFE MEMBER AM LEGION-40/8-DAV
7 MIL SPEC MAINTAINED MV'S
COL. BRUNO BROOKS (ARMY MOTORS) IS MY HERO

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Re: IMPORTANT M-38/M-38A1 REMINDER

Post by Cabin Fever » Sun Apr 24, 2016 7:32 am

So yesterday when I was lubing my A1 i noticed the plugs in the rear axle. It appears they were installed using an Allen wrench. The spring loaded relief valve indicator was in a downward position but it moved freely upward when I tugged on it. I'll have to remove the plugs and install a couple of zerks.

Thanks
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Re: IMPORTANT M-38/M-38A1 REMINDER

Post by Joe Gopan » Sun Apr 24, 2016 7:39 am

And you can leave the fittings in. They left the factory that way. The Idea is to only grease these two fittings per the L.O. Too often can blow the outer axle seals.. There is an article in PS Magazine way back in M-38/M-38A1 days explaining not to get carried away with the grease gun.
2011 MVPA PIONEER AWARD - MVPA #1064
HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
LIFE MEMBER AM LEGION-40/8-DAV
7 MIL SPEC MAINTAINED MV'S
COL. BRUNO BROOKS (ARMY MOTORS) IS MY HERO

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Re: IMPORTANT M-38/M-38A1 REMINDER

Post by CT Trooper » Mon May 02, 2016 11:54 am

Do you know what size the Zerk fittings are?

Thank you,

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Re: IMPORTANT M-38/M-38A1 REMINDER

Post by Joe Gopan » Mon May 02, 2016 2:01 pm

1/8" Pipe Thread, SAE spec Extra Short.
2011 MVPA PIONEER AWARD - MVPA #1064
HONOR GRAD-WHEELED VEHICLE MECHANIC SCHOOL 1960 - US ARMY ORDNANCE SCHOOL(MACHINIST) ABERDEEN PG 1962 - O-1 BIRD DOG CREWCHIEF - 300,000+TROUBLE FREE M-38A1 MILES
LIFE MEMBER AM LEGION-40/8-DAV
7 MIL SPEC MAINTAINED MV'S
COL. BRUNO BROOKS (ARMY MOTORS) IS MY HERO

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Re: IMPORTANT M-38/M-38A1 REMINDER

Post by CT Trooper » Mon May 02, 2016 4:23 pm

Much appreciated!

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Re: IMPORTANT M-38/M-38A1 REMINDER

Post by CT Trooper » Tue May 03, 2016 11:26 am

Installation completed today!


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