This is an attempt to identify the variations in transmission skidplates for Willys MB and Ford GPW.
I do not have enough information to be absolutely sure about all data on this page, so please email me if you find an error or have some new information. Chris@opie.com
And more pictures are always welcome!
My intention is to add this page to http://wiki.g503.com once we have more complete information and the wiki is upgraded to accept pictures.

Note: Orientation of the following pictures are not the same. When mounted on the jeep, the largest round hole is passenger side ,to the rear.

Chris Fourroux


1: Willys MA
    A-543
  This plate looks very similar to plate #2 below.
  

The MA skid plate measures 14-1/8" long front [top] to back [bottom] along the surface of the plate, and 14" wide side to side. 
-Fred Coldwell
Photo taken from below.

2: very early Slat Grill Willys MB 
    Some say that skid plate #1 above was used. Others say it was a slightly longer version used on the first 1000 or so slat grills.
    TM10-1206 chg 1 Dec. 1, 1941 does not list the skid plate as being interchangeable with the Willys MA.
    There is a drawing on JeepDraw for this plate if you want to make your own.

Photo taken from below From M440-W1, January 1942, Canadian Contracts CDLV-241 and CDLV-242 Maintenance manual. According to Farley, this is for approx serial numbers MB118697 to MB120600.
NOTE: see the positions of the body outriggers? this is an MA frame! and yet, the rear brake hose is in the later MB configuration. Enigma. So this picture doesn't prove anything.


   


3: Slat Grill Willys MB #1
    A-1253
    This is the plate documented as used up to serial number 120700. This plate has been found on several very early slat grills, so maybe, just maybe, our information about plate 2 above is wrong.
It does not have the holes for the separate exhaust pipe guard. I find this to be a very interesting plate. notice the  hole that seems to be cut through. It appears the specs were drawn, the part was made, and then they found out the front left corner hits the oil pan. so they cliped it off but cut through the original hole for the exhaust pipe extension clamp A-1300. So they moved the holes for that clamp farther right. Sometime before serial number 120700 was reached, this plate lost the "mistake" holes. see plate #4 below.

Photo taken from above


4: Slat Grill Willys MB #2
    A-1253
    This plate is identical to #3 above except it does not have the cut through holes for the exhaust pipe extension clamp A-1300.
It would seem that when the supply of the modified plate #3 above ran out, a new batch was made, and of course, they would not have the "mistake" holes in them.
I thought this plate might exist. Francis Van Damme verified it. He has an exact reproduction that he made from an original as shown here. It is unknown when this change occured but it would have to be before serial number 120700.

Photo taken from above


5: Production MB
    A-1253 with A-5415
    Used after serial number 120700. This plate is almost identical to plate #4 above except two holes are added to the side to attach A-5415 Exhaust pipe guard.

Photo taken from above Photo taken from above

 


6: MB one piece for external contracting brake
    A-1253
    Yes, it's still the same part number according to SNL G-503 Ord 9
    I don't have a picture of this one but I surmise it looks like skid plate #7 with the exception that there is no "dent" in the rear to accommodate the larger internal expanding brake.
Unknown when the change to this plate occured.
(no picture)


7: MB one piece for internal expanding brake
    A-8858
    in SNL G503 Ord 9, there is no corresponding GPW part for this one.
    I imagine this plate was probably used about the same time as the change to the internal expanding brake, Sept '44 at serial number 373337 according to Nabholtz.

 Photo taken from below   Photo taken from above and right side




8: Late MB one piece for internal expanding brake
    A-8858?
Same as the plate #7 above but with one more slightly larger hole for the transfer case rubber mount bolt.
Unknown when the change to this plate occured but has been found on a March '45, a June '45 MB, and a very late '45 MB

Photo taken from below Photo taken from below




9: GPW one piece for external contracting brake
    GPW 5291-B
    The "B" in the part number in SNLG503 Ord 9 makes me think there was an "A", but this is the only number I can find so far.
    Notice it is very similar to plate #8 above except the large front hole is round instead of oval and the center hole in the string of 5 holes is larger

Photo taken from below and from the front. photo taken from above

 


POST WWII skid plates ( we think )
These are variations we believe to be from either CJ's or M-38's


10: CJ plate
    Notice the 4 holes that are off center at the rear. The angle of these holes matches the angle of the rear drive shaft as it comes off the transfer case. Thanks to Tom in RI, we now know what they are for as well as the two extra small holes at the front of the plate.

photo taken from above

 


11:
    This plate has been found on several M38's
    like #10 above but with 4 more large holes under crossmember and 4 more small holes

Photo taken from above


12:
    Possibly a later version of the M38 plate. New data: this plate has been found on CJ-3a's and believed to be original
    Like #11 above but with half circle cutout for front drive shaft and 2 more small holes

Photo taken from above


13:
Possibly an even later version of the M38 plate.
Like #12 above but with even more holes!

Photo taken from above


14: French made skid plate
   WOF,Hotchkiss
    Very like #9 above except for that  interesting oblong hole.

Photo taken from below and from the front.

 


 

Questions:

1 What skidplate was made by Willys of France and can you tell the difference?  Thanks Vivian!
2 Aren't there anymore Ford GPW plates?
3 right now post WWII plates are pretty much lumped together but are there differences between plates used on CJ-2a, CJ-3a, CJ-3b etc?
4 what about M38-A1's?