Starter Block

Searching for the elusive Block

The CJ-3A (up to mid 1952) and the CJV-35/U both use similar "kick start" starters. Instead of being activated by turning the key these starters are mechanically engaged by pushing on a pedal with your right foot. The pedal is located low on the firewall under the dash, inline with the starter motor. From the pedal a push rod passes through a bushing that is screwed to the firewall and then the rod connects to the starter. The bushing keeps the pushrod lined up with the starter. The hole in the bushing is about the same size as the pushrod and the hole in the firewall is about 3/4" to allow ample room for wear.

In the Willys parts manual this bushing is called a "Block, starter rod to dash". Part number 647940 is for the CJ-3A and part number 801479 is for the CJV-35/U. The photo on the right illustrates the location of all the components involved. For years I searched for a CJ-3A with the original Block... to no avail. It seemed that every Jeep was different. This could indicate that the original part was a weak link, since it is often missing or modified. As it turns out, the Block is actually just a 1"x 2"x 1/4" block of wood. Since the push rod is located so far toward the passenger side, excessive pressure is applied to the block if the driver is not careful to push the pedal straight in. This side load probably accounts for a high failure rate of the Block. It must have been giving Willys engineers problems also because they made several changes to the part early on. Originally part number 647940 was released for production on 6/29/1948. It was made from tempered masonite. Within months of being released, on 11/12/1948, the material was changed to "Wood - white oak, yellow birch or hard maple". Apparently this change did not work as well as Willys engineers had hoped since it was quickly changed again on 1/26/1949 to "Waterproof glued plywood (gumwood)". The plywood must have given satisfactory service since it doesn't appear any other changes were made. In the 1960 parts price list the 647940 Block is still available at a list price of $0.11. On 3/28/1950 when the CJV-35/U was about to enter production another Block was introduced for use on this limited production model. This part, number 801479, was to be made from Masonite die stock with the same dimensions as the CJ-3A Block. Both vehicles use two #10x5/8" tapping screws to attached the block to the firewall. Below is a drawing of the Block.

What kind of Block is on your CJ-3A? Please let me know by sending an e-mail, click here for my contact information. If you have a photo send it to me also. Thanks to Keith Buckley for detailed information about the starter blocks and all the CJ-3A owners who sent me photos and descriptions of their blocks.

cj3a 6/06