I have a 1978 F250 with a 400. Just getting ready to fire it up. but I have a problem with the hex drive for the oil pump. The drive has a washer thing about 1/2" down the one end of it and it does not fit. The other drives I have used have not had this and there for just slid right in. The diameter of the washer is just slightly larger then the diameter of the bottom of the distributor. Was I supposto put the drive in when I installed the oil pump? or can I take the washer off and just drop it in?

 

the washer is to keep you from pulling it out of the oil pump when you pull the distributer as the shaft will then fall in the oil pan and guess what you put the dist back in no oil pressure, it was to be put in with the oil pump with the washer up by the cam. you can put it in by dropping the pan and oil pump but not easy, put the shaft in and take a rubber band around the shaft to a main bolt to hold it in place the stad the oil pump, if you take the washer off you problry will miss the oil pump anyway and nothing solved

 

I had this exact same problem last week when I replaced my oil pump. I did not have enough room to move around underneath my truck and install the oil pump drive (long story, but it is a hot rod!). So, I installed it from the top. That washer is just there to prevent the shaft from falling into the pan when you pull out the distributor. It gets installed with the washer closest to the distributor, from the underside.

Using a somewhat "tricky" installation, I got it in. I found a deep 1/4" drive socket that fit the hex. I then used a fair amount of grease and filled the socket with it. The grease is enough to hold the shaft in the socket so it doesn't fall out and into the pan when you go to install it, which you will then have to drop your hole oil pan....if it does fall in Anyway, I then took a long 1/4" extension and put that into the socket and installed the hex drive into the pump. I then used a ratchet and turned my oil pump so I new I had "hit" the oil pump with my hex drive. Now it gets a little trickier. In order to pull out the socket and not the hex, I used a small screw driver and held the socket down and pulled out the extension, leaving the socket on the hex drive shaft. I then took that same small screw driver, poked it through the back of the socket, and using a magnet, I pulled the socket up the shaft of the screw driver. This was a rather easy procedure, and I think it took me longer to type this than it did to install my shaft. Good luck

 

To put it mildly, it is a lot easier to install the shaft properly from the start. Remember that when you pull the distributor next year and drop the shaft into the pan...

When installing the shaft properly from below remember to place a spacer washer on top of the spring washer "keeper" that is about 1/2" from the end of the shaft. Install the pump and shaft to set the position of the spring washer. Then drop the pump and remove the extra spacer washer. Your spring washer "keeper" is now positioned properly.

The spring washer keepers don't always work. I have seen spring washers installed half way down the shaft which of course does not work. I have also seen the distributor shaft hold the hex shaft so tight that the keeper slid down the hex shaft. Of course since Murphy is in charge of things like this the distributor released it's hold on the shaft halfway out and the hex shaft dropped into the bottom of the pan. -The best laid plans of mice and men...

 

well since the engine was just dropped in 2 days ago, and priming it full of oil with a drill is all I have left to do, I think im gonna take a change and drop it in from the top. I have used a simular method to 53fatfndr with the grease holding it in, except I filled the bottom of the distributor with grease and then put the oil pump drive into that. but in this case I can not do that since I need to get a drill onto that drive to prime the engine full of oil. Next time I will put the drive in before the pump and pan. Thanks for all the help