L 134 Connecting Rod Cross Ref Help

1941 - 1945, MB, GPW Technical questions and discussions, regarding anything related to the WWII jeep.
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Restonut
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L 134 Connecting Rod Cross Ref Help

Post by Restonut » Tue Apr 02, 2013 9:16 am

I am hoping someone may be able to shed some light on connecting rod part numbers/ cross refernce. I am trying to put together a late MB block and I am having some difficulty in finding rods that will work. I understand that rods with part number 639999 and 64000 are "correct" as far as the parts manual but I am finding other part numbers such as 641775/641774 that are said to work as well.

I have rods with part number 640068 WO 21C and 640068 WO 36D that came out of a '46 CJ2A.( Appear to have 7/16 bolts)
I have also run across part number 640068 WO 47B and WO 66 that is claimed to come out of a '43 MB motor. ( Bolt size unknown)

The problem I have is I have not been able to find any information on what part number rods will work in my MB block. I know there are differences in bolt size as well as bolt head clearance that was made for chain driven cams versus gear driven etc.

Any help would be appreciated!!


Thanks
Dave
1945 MB 454351 (under construction)
1942 F-Script # 3735
1943 MBT


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Chuck Lutz
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Re: L 134 Connecting Rod Cross Ref Help

Post by Chuck Lutz » Tue Apr 02, 2013 12:50 pm

I checked the ORD 9 SNL GH-503 from 1945 and found the following:
Rod 1&3 WO-639999 was superseeded by WO-640071
Rod 2&4 WO-640000 was superseeded by WO-640072

Now I don't know when the change took place but I think if you have a late motor maybe that means gear drive and maybe that requires the 640071/640072 rods?

Those other numbers are not in the 1945 edition so I would steer clear of them unless you get a Willys motor expert to comment...
Chuck Lutz

GPW 17963 4/24/42 Chester, PA. USA 20113473 (USA est./Tom W.)
Bantam T3-C 1947

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Sean Collins
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Re: L 134 Connecting Rod Cross Ref Help

Post by Sean Collins » Tue Apr 02, 2013 3:35 pm

Dave:

640068 is a casting number. Rod part numbers 640071/72 were made from this casting. I don't know what casting was used for the p/n 639999/640000 rods (possibly the same).

640071/72 rods (7/16" bolt) were used in late MB, and CJ-2A engines (both chain & gear) up to early Jan. '47.

641774/75 rods (3/8" bolts) used a new casting # 641770, were used from Jan. '47 on.

640071/72 and 641774/75 rods are interchangeable. Don't know about the 639999/640000 rods, but suspect they are too.

Sean

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Re: L 134 Connecting Rod Cross Ref Help

Post by Phil Pizzi » Tue Apr 02, 2013 5:50 pm

Hope this helps. Drew a blank on 639999.

641774 and 641775 are both listed in FEDLOG so they had Military applications.

640000 part # in FEDLOG crosses to 641775 part # (also Part #s 7743751, 640036). Both have the same stock # 2805003607917 .

specs on 2805003607917 :

Characteristics (Decoded)

MRC REQUIREMENT STATEMENT CLEAR TEXT REPLY
NAME ITEM NAME CONNECTING ROD,PISTON
CROSS-SECTIONAL SHAPE STYLE I-SECTION TYPE
FABRICATION METHOD CAST AND MACHINED
SHAFT CONNECTING END STYLE AUTOMOTIVE STANDARD SPLIT BEARING 2 BOLT
END WIDTH 1.215 INCHES NOMINAL
END THICKNESS 0.939 INCHES NOMINAL
EDGE RADIUS 0.634 INCHES NOMINAL
END HOLE INSIDE DIAMETER 0.812 INCHES NOMINAL
PISTON CONNECTING END BEARING NOT INCLUDED
PISTON CONNECTING END LUBRICATION DRILL FEATURE NOT INCLUDED
PISTON CONNECTING END LUBRICATION METHOD SPLASH
SHAFT CONNECTING END BEARING NOT INCLUDED
SHAFT CONNECTING END HOLE INSIDE DIAMETER 2.044 INCHES NOMINAL
SHAFT CONNECTING END EDGE RADIUS 1.522 INCHES NOMINAL
SHAFT CONNECTING END WIDTH 3.260 INCHES NOMINAL
SHAFT CONNECTING END THICKNESS 1.207 INCHES NOMINAL
SHAFT CONNECTING END LUBRICATION DRILL FEATURE INCLUDED
SHAFT CONNECTING END LUBRICATION METHOD FORCED-FEED
CENTER TO CENTER EFFECTIVE LENGTH 9.178 INCHES NOMINAL
BODY WIDTH AT PISTON CONNECTING END 0.905 INCHES NOMINAL
BODY WIDTH AT SHAFT CONNECTING END 1.062 INCHES NOMINAL
BODY THICKNESS AT PISTON CONNECTING END 0.562 INCHES NOMINAL
BODY THICKNESS AT SHAFT CONNECTING END 0.562 INCHES NOMINAL
PISTON END CONNECTION STYLE CLAMP
MATERIAL STEEL
Phil Pizzi
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1942 Script GPW S/N 9552

Restonut
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Re: L 134 Connecting Rod Cross Ref Help

Post by Restonut » Wed Apr 03, 2013 9:10 am

Guys:

Thanks for the input, that does help me out tremendously. My bad on the casting number/part number mix up I am used to the casting number and part numbers being the same as with many GM/Ford/Mopar components. I think it is interesting that the casting numbers and part numbers both have same format.

What do the extra casting numbers stand for such as 640068 WO 21C? Is this a date code?

The other thing I have seen is that the 7/16 bolts used in the earlier rods such as 64000/63999 are apparently different than the later 7/16 versions used for gear and or chain drive engines.


Dave
1945 MB 454351 (under construction)
1942 F-Script # 3735
1943 MBT

willik43
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Re: L 134 Connecting Rod Cross Ref Help

Post by willik43 » Sun Apr 07, 2013 12:31 am

Hi,
I have 3 sets of con rods now:
641770
130406_ojniceCJ3Aw_11.jpg
130406_ojniceCJ3Aw_11.jpg (57.24 KiB) Viewed 833 times
640068
130406_ojniceGPW_02w.jpg
130406_ojniceGPW_02w.jpg (58.27 KiB) Viewed 833 times
636960
130406_ojniceTauer_06w.jpg
130406_ojniceTauer_06w.jpg (52.21 KiB) Viewed 833 times
Do you have any idea of where they have been used / timing?
Thanks in advance.
Petr
*********************
1944 GPW 194969 - Louisville Plant
1945 MB 423482 - ex Greek Army (salad)

Marty, SoCal
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Re: L 134 Connecting Rod Cross Ref Help

Post by Marty, SoCal » Sun Apr 07, 2013 6:03 am

Late rods use 3/8" bolts.

There are also GPW rods, the rod bolts are 7/16" and formed as part of the rod.

The rods will basically all interchange, but the gear drive engines need to be checked to make sure that the heads of the rods clear the cam lobes, later rods have beveled rod bolt heads.

I would recommend using matched sets and checking their weights, big and small end, and total weight for best engine operation.

willik43
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Re: L 134 Connecting Rod Cross Ref Help

Post by willik43 » Fri Dec 08, 2017 7:26 am

Now I don't know when the change took place but I think if you have a late motor maybe that means gear drive and maybe that requires the 640071/640072 rods?
Reading Lloyd White, Vol 4 - Production Changes, there is a change listed: "Connecting rod and connecting rod bolt redesigned. (To strenghten large end of connecting rod and to make it less sensitive to heat treatement.) Date started in production 5-15-44"
I would suppose this is the date of change of WO-639999/64000 to WO-640071/640072 production.
Do you have any info about GPW changes?
Petr
*********************
1944 GPW 194969 - Louisville Plant
1945 MB 423482 - ex Greek Army (salad)


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