FALCON DISTRIBUTOR GEAR WEAR
The distributor drive misalignment problems with the Falcon engines appear to be predominantly with the XE and XF models. It appears as if that there was at least one batch of engine blocks machined incorrectly. As this problem occurred prior to the purchase of the multi axis checking machine, Ford had no easy way of finding the fault. We know of no simple way to check the blocks in the field.
A modification to the distributor drive gear on the cam was made to reduce the problem. The XE and XF cams also appear to have gears that differ from specifications. The gear design used on the crossflow engines is the same design used since the first Falcons. We have, to my knowledge, never had a problem with a non crossflow Falcon.
We have several customers who regularly fit high volume pumps without incident. However a high volume pump tends to aggravate the problem if it is there, especially if used with heavy weight oil.
Once we tracked down the cause of the problem we have taken steps to change our gears closer to the modified design found on the XE and XF. This has reduced the incidence of problems. The drive gears on our cams have also been induction hardened to improve durability. We can supply a distributor gear made from an improved material, refer below for correct part number. The fitting of these gears on an undamaged cam has been successful in eliminating the gear wear in problem engines.
We have had at least one case of the customer adding shims to the distributor shaft between the gear and body. This has caused the gear to be locked stationary when the distributor is clamped down. The end clearance in these engines is controlled by the spacing between the end of the distributor and the boss in the block. Distributor end clearance should be 0.025" -0.033". Other things to check for include using the small shaft distributor in the early block will give too much clearance on the support bush on the block.
Part Number Shaft Size Application
DG2 0.490" XD points distributor All electronic distributors.
DG2A 0.530" XC points distributor.