Panhead Motor and Transmission Install

Kevin Baas has his freshly rebuilt Panhead motor and transmission, and he’s all set to mount them into the rigid frame of this Panhead Bobber. Kevin stresses the importance of having good, flush, clean, flat, frame pads and Panhead motor case flats for mounting the motor properly.

If any repairs are needed in these areas, it is important that they are addressed prior to the Panhead motor installation. The back of the Panhead motor crankcase is considerably thicker than the front. In order to avoid any possibility of cracking the crankcase, it is important to evenly tighten the two rear motor mounts first. It is always important that motor mount hardware is of grade 8 or better quality.

Apply a small amount of red Loctite to the four Panhead motor mount bolts. With the rear mounting hardware tightened, use a feeler gauge to determine if shimming is necessary between the frame pad and Panhead motor case in the front. If it is determined that there is space between the frame pad and crankcase, it is vital that shims are installed prior to tightening the front Panhead motor mount bolts. If no damage or wear has occurred to either of the surfaces, it is likely that shimming will not be necessary.

When installing the Panhead transmission, it is usually easier to bolt the transmission plate onto the transmission case prior to mounting the plate to the frame. Kevin mounts the plate onto the frame first in order to give us a better visual. Like the motor mount hardware, the transmission mounting hardware should also be of grade 8 quality or better. This stock assembly uses an adjuster bolt and plate for adjusting the transmission’s position.

The Panhead transmission hardware should be left finger tight until the inner primary case and primary drive is installed. Once correct alignment and belt tension is achieved, the transmission should be evenly tightened to the Panhead transmission plate.

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