Oil Pump indexing and 7:00

[DonaldSmith]

Often times, after we have worked on the engine, our ignition system is dead or fires horribly, only to discover that the No. 1 position on the distributor cap is not at 7:00, and not even at the opposite side, at 1:00.  The secret lies in indexing the oil pump properly, since the slot in the drive shaft receives the tongue of the distributor shaft.  My Shop Manual hides this explanation after two pages of electrical diagrams. 

 

Paraphrasing, if you screwed with the crankshaft with the pump removed, (or screwed with the pump, or even installed it straight on,) you screwed up the distributor setting.  Then the Shop Manual describes the method of determining top dead center of the compression stroke of No. 1 cylinder, which we all should know about by now.  Then it says: (Underlining and asterisks added)

 

"Turn pump drive shaft until the slot in the end of the drive shaft lines up with the slot in the end cap screw holes

in the mounting flange. (Fig 14). * Then turn the drive gear one tooth counter-clockwise. 

Loosen the distributor lock screw and raise the distributor just enough to allow the pump to be installed. 

Tighten pump cap screws.  With Distributor still raised, turn rotor as shown in Figure 15* 

until it points to about "seven o'clock", move the rotor back and forth slightly to allow the tongue of the distributor shaft

to engage with the slot of the oil pump drive shaft.  Install number one spark plug and distributor cap,

adjust timing as outlined in this section. " 

 

* Figure 14:  (Looking at the pump from the top of the engine, as one would install it, drive shaft up, opposite screw holes horizontal. ) 

** Figure 15:  (Distributor lock plate to the left, retaining snaps horizontal, rotor at 7 :00) 

 

Whew.  Good luck.   Remember, the damn gear of the pump will move one tooth when you install the pump, so compensate for it, or move your spark plug wires around. 

 

 

 

, 

[MarcDeSoto]

Thanks, Donald.  This is what was looking for.  I think I put my dist. in pointing at 7:00, but my timing is off about 25 degs. advanced.  Maybe that could be solved with a major dist. adjustment, but the manual doesn't say how to do this.  I know you would just loosen the major adjustment bolt and turn the dist.  So I'm not sure what approach to take: index the oil pump or do a major adjustment?  

[DonaldSmith]

The distributor adjustment would be easier providing that there is no interference with the vacuum advance, etc. Then the oil pump. 

Here's the stuff from the shop manual