Oil pump driveshaft engagement - The 1947 - Present Chevrolet & GMC Truck Message Board Network

67CC · 01-03-2015, 01:12 PM

Just had the 327 out to spruce up a few things. Bought a rebuilt distributor and am having problems getting it to engage oil pump driveshaft. I've used an oil pump priming tool and have pressure and yes, the gauge works. Have an Edelbrock manifold on which the distributor boss is lower than stock. With the original dizzy, I had to add spacers. When I first tried to start, no pressure. Took out spacers, had pressure, but couldn't get it started and flooded it. Fixed that, made sure dizzy was flush against boss, finally started after first running down the battery and no pressure.
This is just one of a number of things that seem to be out of the Twilight Zone on this project(my fan belt shrank while it was out. WISH I was making that up, but I'm not.).

Any ideas appreciated.

BruthaMan · 01-03-2015, 01:48 PM

Make sure the distributor gear is not on upside down. Probably not, but you never know.

Having said that, I'll share an embarrassing experience that most men would never openly admit to. I spent over twelve hours (over three days) trying to seat a distributor on my '78 383 stroker. It was probably the most frustrating mechanical experience I ever endured.

It simply would not seat. That included me literally crawling into the engine compartment with a flashlight and long screw driver and adjusting the oil pump gear.

I finally pulled the distributor and ground down both sides of the tip (where it engages with the oil pump) a little on each side. Cleaned it up good, and it seated on the first try. The tip was just a hair too big to fit down into the oil pump slot.

What a miserable experience that was!

67CC · 01-03-2015, 02:46 PM

Hey, I've already crawled in there with a flashlight and screwdriver to turn the oil pump slot too! At least I'm not alone. This may be my most frustrating mechanical experience too.
Do you know if the tang inside the gear goes through to both ends?

BruthaMan · 01-03-2015, 04:12 PM

The end of the distributor shaft is tapered such that when the gear is removed, it looks like an oversized screw driver.

In my case, I took the gear off by using a small punch and hammer to knock the pin out that holds the gear onto the end of the distributor shaft.

Once off, I had a table belt grinder that I fired up, and lightly took off a little on each side of the end of the shaft, then put the gear back on, and it dropped right into the oil pump shaft and seated like it should.

With the gear on the shaft, it will fit down onto the oil pump shaft. The slots on the oil pump shaft match into the slots at the end of the distributor shaft when the gear is in place. My problem was, that the end of the distributor shaft was just a few one hundredths too big from allowing it to seat on the oil pump shaft, but once I ground both sides down a little, it went right into place.

**MySons68C20** · 01-03-2015, 04:59 PM

I'll put on the "something to check" list before installing. Thanks for sharing

67CC · 01-03-2015, 08:31 PM

Took dizzy out again (lost count of how many times that is now

) and can see the problem you had. Had old driveshaft still lying around so I put it in the old dizzy and it's a snug fit.

Reseated the whole thing and now I have oil pressure AND it runs. Do not ask me what I did differently. Just in keeping with this whole project, I guess.

Anyway, thanks for your help, bruthaman, and I do like your truck. Looks much better than mine.

BruthaMan · 01-03-2015, 08:55 PM

Glad to hear you have it working. Little things like that can make simple progress come to a screeching halt!

70' · 01-04-2015, 10:13 PM

I too have spent hours with the long screwdriver attempting to adjust an oil shaft and it sucks. I had an old school guy at one of the shops I used to tinker in show me a nifty little trick to fix that whole situation so I thought I would share. Don't worry about the placement of the shaft at all, go ahead and set your distributed in the hole with the rotor lined up where you want it pushing it as far as it will go until it hits the shaft lined up or not. Have a friend gently keep downward pressure on the distributor while you turn the engine over. The distributor will drop in place once the shaft lines up properly. Slickest darn thing I ever seen, and it sure beats the ol' long screwdriver trick!

01-03-2015, 01:12 PM	#1
67CC Registered User Join Date: Aug 2011 Location: Milwaukee, WI Posts: 23	Oil pump driveshaft engagement Just had the 327 out to spruce up a few things. Bought a rebuilt distributor and am having problems getting it to engage oil pump driveshaft. I've used an oil pump priming tool and have pressure and yes, the gauge works. Have an Edelbrock manifold on which the distributor boss is lower than stock. With the original dizzy, I had to add spacers. When I first tried to start, no pressure. Took out spacers, had pressure, but couldn't get it started and flooded it. Fixed that, made sure dizzy was flush against boss, finally started after first running down the battery and no pressure. This is just one of a number of things that seem to be out of the Twilight Zone on this project(my fan belt shrank while it was out. WISH I was making that up, but I'm not.). Any ideas appreciated. __________________ '67 C20 Custom Camper. 327, three-on-the-tree. No power anything!

01-03-2015, 01:48 PM	#2
BruthaMan US Army Veteran Join Date: Nov 2008 Location: Central Texas Posts: 1,049	Re: Oil pump driveshaft engagement Make sure the distributor gear is not on upside down. Probably not, but you never know. Having said that, I'll share an embarrassing experience that most men would never openly admit to. I spent over twelve hours (over three days) trying to seat a distributor on my '78 383 stroker. It was probably the most frustrating mechanical experience I ever endured. It simply would not seat. That included me literally crawling into the engine compartment with a flashlight and long screw driver and adjusting the oil pump gear. I finally pulled the distributor and ground down both sides of the tip (where it engages with the oil pump) a little on each side. Cleaned it up good, and it seated on the first try. The tip was just a hair too big to fit down into the oil pump slot. What a miserable experience that was! __________________ 1972 C10 Highlander - The making of a daily driver

01-03-2015, 02:46 PM	#3
67CC Registered User Join Date: Aug 2011 Location: Milwaukee, WI Posts: 23	Re: Oil pump driveshaft engagement Hey, I've already crawled in there with a flashlight and screwdriver to turn the oil pump slot too! At least I'm not alone. This may be my most frustrating mechanical experience too. Do you know if the tang inside the gear goes through to both ends? __________________ '67 C20 Custom Camper. 327, three-on-the-tree. No power anything!

01-03-2015, 04:12 PM	#4
BruthaMan US Army Veteran Join Date: Nov 2008 Location: Central Texas Posts: 1,049	Re: Oil pump driveshaft engagement The end of the distributor shaft is tapered such that when the gear is removed, it looks like an oversized screw driver. In my case, I took the gear off by using a small punch and hammer to knock the pin out that holds the gear onto the end of the distributor shaft. Once off, I had a table belt grinder that I fired up, and lightly took off a little on each side of the end of the shaft, then put the gear back on, and it dropped right into the oil pump shaft and seated like it should. With the gear on the shaft, it will fit down onto the oil pump shaft. The slots on the oil pump shaft match into the slots at the end of the distributor shaft when the gear is in place. My problem was, that the end of the distributor shaft was just a few one hundredths too big from allowing it to seat on the oil pump shaft, but once I ground both sides down a little, it went right into place. __________________ 1972 C10 Highlander - The making of a daily driver Last edited by BruthaMan; 01-03-2015 at 05:35 PM.

01-03-2015, 04:59 PM	#5
MySons68C20 Senior Member Join Date: Sep 2014 Location: Wenatchee, Wa Posts: 929	Re: Oil pump driveshaft engagement I'll put on the "something to check" list before installing. Thanks for sharing

01-03-2015, 08:31 PM	#6
67CC Registered User Join Date: Aug 2011 Location: Milwaukee, WI Posts: 23	Re: Oil pump driveshaft engagement Took dizzy out again (lost count of how many times that is now) and can see the problem you had. Had old driveshaft still lying around so I put it in the old dizzy and it's a snug fit. Reseated the whole thing and now I have oil pressure AND it runs. Do not ask me what I did differently. Just in keeping with this whole project, I guess. Anyway, thanks for your help, bruthaman, and I do like your truck. Looks much better than mine. __________________ '67 C20 Custom Camper. 327, three-on-the-tree. No power anything!

01-03-2015, 08:55 PM	#7
BruthaMan US Army Veteran Join Date: Nov 2008 Location: Central Texas Posts: 1,049	Re: Oil pump driveshaft engagement Glad to hear you have it working. Little things like that can make simple progress come to a screeching halt! __________________ 1972 C10 Highlander - The making of a daily driver

01-04-2015, 10:13 PM	#8
70' Registered User Join Date: Nov 2014 Location: Dickinson, ND Posts: 197	Re: Oil pump driveshaft engagement I too have spent hours with the long screwdriver attempting to adjust an oil shaft and it sucks. I had an old school guy at one of the shops I used to tinker in show me a nifty little trick to fix that whole situation so I thought I would share. Don't worry about the placement of the shaft at all, go ahead and set your distributed in the hole with the rotor lined up where you want it pushing it as far as it will go until it hits the shaft lined up or not. Have a friend gently keep downward pressure on the distributor while you turn the engine over. The distributor will drop in place once the shaft lines up properly. Slickest darn thing I ever seen, and it sure beats the ol' long screwdriver trick!



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