Comparison of Transfer Cases

[Tony Smith]

I know it's been a while since this thread was last active, but there's always a good time to add new info.

From David Hayward's pics above, we have ruled out that the CMP transfer case bears no relation to to the 2 1/2 ton CCKW or 1 1/2 ton Chevrolet used by the US. However, there is another US military truck that does indeed appear to have some similarities to the CMP case; the Ford GTB 1 1/2 ton truck.

As these vehicles were built by Ford in 1943/44, it is safe to say that they followed on from the CMP design, but there a few differences. The CMP case is what is known as a Right-hand drop design, that is the input shaft is on the vehicle centreline while the output shafts are well to the right of the vehicle's centreline. The Ford GTB transfer case however is a Left-hand drop design, as the engine and gearbox are located well to the right of the vehicle centreline and so its the transfer case input shaft, but the output shafts are close to vehicle centre.

CMP transfer cases that have a handbrake have this fitted to the rear output shaft, but the GTB has the handbrake mounted on the rear side of the input shaft, where normally a PTO is fitted to the CMP.

Does anyone have an exploded parts diagram of a GTB transfer case, or better yet, do any members own one. Of all the US vehicles, the GTB is probably the closest in design to the CMP, and it is clear that Ford drew heavily from the CMP design.

Photos below are from Toadman's tank Pictures