Distributor won't drop in fully...

T

Thearne3

Member
I'm already feeling stupid: I rebuild my distributor and went to drop it back in the engine. The lower shaft fits into the slots above and I can see it drop into the slot below when I turn the cam. Even so, the distributor sits 1/4" above the head!

Is there an adjustment I'm not aware of? What am I doing wrong?

Must be something stupid!

Tom
 
remove the distributor, and stick a long straight blade screwdriver down through
the head. Rotate the lower shaft with the screwdriver and see if you have the lower shaft 180 degrees off of the oil pump drive gear.
 
Another possibility is that you're not engaging the small locator pin on the bottom of the distributor with the corresponding hole in the head. That can be a bit of a chore. Failing to engage that pin can result in the signs you are seeing.

JayJay
 
If you replaced the shaft the new one may need to be fitted. A shaved head, or decked block comes into play. And a standard length shaft(s) may now be too long.
 
Had to gently tap mine in after the index pin hit the hole in the head. Did the same thing the last time I had it out and it was no problem removing it this time when I replaced head gasket. GENTLY
 
Brentwood Bob said:
If you replaced the shaft the new one may need to be fitted. A shaved head, or decked block comes into play. And a standard length shaft(s) may now be too long.
Click to expand...
If his shaft length is off 1/4" then he's really got issues!

I took a trashed one-piece shaft out of a distributor and replaced it with a new two-piece shaft and found that the length was fine. However, I did have to reduce the diameter of the upper portion of the lower shaft by a few thou so that it would fit inside of the coupling - the offset of the slot was just that much out.

But if OP is using the original shafts that should not be in issue, unless somehow the two ends of the lower shaft are different.

JayJay
 
Slot deep enough? Detritus in the driver from the sides of the hole thru the head, lightning
Bolt. We can't see so we just make a guess.
 
Thanks for all the replies!

1. Locator pin in distributor body is also above the head, so not an issue.
2. Lower shaft sticks in upper shaft, so when I lift the distributor, the whole thing comes out. So I'm confident that the upper slot is fully seated.
3. I've tried rotating the shafts 180 degs. and in each case they engage with the pin in the block. Both ways give the same 1/4" gap between distributor and head.
4. Shining a light down into the hole: there seems to be some crud next to the pin. Can't tell what it is...HOW THE HECK CAN I CLEAN THAT OUT?? It may be keeping the shaft from seating properly.
 
SOLVED: Distributor won't drop in fully...

Thanks to all!

I realized that I have access to the distributor drive gear behind the valve cover. (told you I was feeling stupid!). 5 min to remove the oil return and valve cover and presto: i could see some debris in the top of the distributor gear. Then found that the replacement shaft slot was not wide enough to fit over the pin and filed that. It's a lot easier when you can see what's going on!

Now that I have the two oil access points, the two shafts should stay rust free...

Again, thanks to everyone for your help!
Tom
 
Tom, you did everything according to the book. The instructions say that you may have to file the slot to make things fit or may have to grind off a bit of the shaft. Good job.
 
If you replaced the Oil Pump / Distributor Drive Gear and it is not fully seated as shown in the attached picture, it will prevent the Distributor from sitting flush with the top surface of the Engine Head by the same amount of gap.

This happened to me when I replaced the Oil Pump / Distributor Drive Gear in my 1930
Model A pickup Truck.

I had to turn the engine over by hand using the Hand Crank Tool and that allowed the Oil Pump / Distributor Drive Gear to properly mesh with the gear teeth on the Cam Shaft.

Doing that made the Oil Pump / Distributor Drive Gear drop down and sit flush with the top surface of short boss in the Engine Block Oil Gallery.

Now the bottom surface of the Distributor sits flush with the top surface of the Engine.
Make sure that the Guide Pin on the Distributor sits into the corresponding hole in the Engine Head.

Hope this helps,
Elmopquackenbush
1930 Model A Ford Pickup Truck
 

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The distributor shaft components like to corrode due to condensation in that area. I spray the parts with LPS-3 rust inhibitor before installing them. I use anti seize on the coupling areas. I've had the coupler joints weld together with corrosion before.
 
I have a similar problem that I would like to be able to fix without taking off the valve cover (if possible).

I removed the distributor body, which came out easily, leaving the lower distributor shaft (stainless) in place on the oil pump. The lower shaft did not come out easily and when I pulled on it the entire oil pump lifted up a bit (felt springy) but the shaft refused to break free. I finally got it to come out after really pulling hard on it.

Now, when I try to put it back together, the lower shaft will not drop down enough to engage with the tang on the oil pump. I looked down the hole with a bore scope (photo attached) and it looks like there's a collar around the tang that prevents the shaft from engaging with it. No matter how many times I rotate the shaft with a screwdriver, it never falls into place in the pump and just spins on top of it. Obviously pulling hard on the lower distributor shaft caused this issue, but I'm wondering if anyone has had a similar situation, and what they did to fix it. Thanks.
 

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Chip2020 said:
it looks like there's a collar around the tang that prevents the shaft from engaging with it. No matter how many times I rotate the shaft with a screwdriver, it never falls into place in the pump and just spins on top of it.
Click to expand...

There is a sleeve around the tang. It may be gunked up enough that the gunk is obstructing the shaft. Certainly the gunk or corrosion was gluing the previous shaft in place. Maybe spray it with penetrating oil? You have to clean it somehow.
 
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