30-31 vs 40-48 Clamshells

[klawockvet]

I have an early AR 6 bolt clamshell and inner u-joint cover and am trying to install an F150 trans. I need a later style 4 bolt cover and clamshell and have one on a 40 that I could use but it will be a bear to get it out. Will they interchange or do I need to find a 30-31? I would much prefer to just buy another one if I could get it on the west coast as I'm running low on time to get the car back on the road.

[vulture]

The 4 bolt cover and grease cup came on the 1932 1933 and 1940 plus. The 1930 1931 would also be a 6 bolt.

[klawockvet]

That puzzles me. I purchased an F150 trans that was built by Delmue in 91. The man I bought it from replaced it with a new Mitchell transmission and overdrive. There has to be more to the story. When I went to install my cover and clamshell I found that it would be impossible as a 4 bolt gasket would indicated the correct bolt holes. I called the seller, thinking he would have the correct parts but he said his original 31 was used and he was using it on his Mitchell trans, which I am told is the same case. When I finally get this sorted out I will have an original transmission in working order with the original 26 dogbone and tab. If anyone needs such an item they can PM or email me.

[Jim Brierley]

I put a 6-bolt cover on my '39 trans years ago. I merely drilled out 4 of the 6 holes to the proper size (7/16") and bolted it in place. The 7/16" nuts are too large on the O.D. so I drilled and tapped the smaller nuts but you might try using spacers between the cover and 7/16" nuts.

[klawockvet]

Unfortunately the 6 bolt cover I have wont cover the adapter plate. I've already tried that. The 4 bolt on an old 40 I have works but I will have to either pull the engine and trans or the rear end to get the inner cover. Not a job for a rainy day. I did pull the clamshell and it fits, so all I need now is to find an inner cover I can get to.

[Bob C]

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Is this similar to what you have, can you post a picture of yours?


Bob

[klawockvet]

Mine is different. I can't get the photo to resize to meet the requirements of uploading. Yours retains the original 6 bolt bearing retainer. Mine does not have any way to attach the bearing retainer. It's bolt holes are designed to bolt the inner grease retainer and the clamshell directly to the adapter plate without using the Ford bearing retainer. I suspect when the kit was first made it included those parts. I also suspect that the design has been changed and there is a better seal between the transmission and U-joint that mine has.

[klawockvet]

My original question assumed there was a difference between early and late clamshells, with the later ones being the 32 to 48 style. Apparently they are not and while there are differences in Model A clamshells they are all require 6 bolts like the one in the picture above. All of my concerns and questions were answered when Dave Delmue, saw this posting and called me. He went to great lengths explaining how the conversion was done and what was needed. He built this set up in 1991 and it has performed as expected and still looks good. Not many suppliers are willing to spend time dealing with 28 year old products that have transferred to a new owner. Hard to find stand up people today in any business.