installing distributor gear drive

sethkestenbaum

sethkestenbaum

Well-known member
I'm looking for some cheats on how to install the distributor gear drive WITHOUT dropping the oil pan. I having the valve chamber "open" and the gear out. It seems that the helical gear on the drive will prevent the tongue on the bottom of the drive to sit properly in the oil pump. What is the secret/trick here?
 
You either have to turn the gear to align to the drive tang or turn the drive tang to align to the gear.

As Bill said turning the crank while "coaxing" the gear onto the pump is the easiest way.

(I suppose you could also hold the crank stationary and turn the engine block to achieve the same results. But that would just be a macho thing.)
 
I haven't added any oil to the engine yet (it is freshly rebuilt and I wanted to get all the parts together first). Is there any issue with using the crank at this time?

I tried dropping it in on each "groove" on the gear.... no luck there.
 
Assuming there was lubricant used during assembly slow turning of the engine to align the gear will not be a problem.

If you want to not turn the engine, continue to try to drop it but use long hemostats to slightly clock the pump tang a couple of degrees. You may get it in a few trys.
 
The drop in just isn't working. I'm trying to be scientific about it, turning the pump just a wee little each attempt and trying every tooth of the gear.

I also broke out the hand crank. The car is in neutral (the car will roll) but the engine won't turn.

I'm open to suggestions and want to avoid dropping the pan.
 
Seth:
Don't have to drop the pan! Bump the engine around with the starter while holding downward pressure and it will slip right in! Or bump it and try dropping in again and you will catch the right tooth. Only takes a few tries.
 
I've been "bumping" the engine with the starter while a buddy applies downward pressure on the distributor gear. We've rotated the crank several times. The tongue on the gear just doesn't want to drop into the groove on the pump. I am uncertain why. Thoughts? What am I missing here?

Didn't someone say that this would be easy? What is the possibility that the tongue and slot just are "too tight a fit" to line up in this fashion?
 
Maybe you are pushing down hard enough to make the oil pump shaft turn as the drive gear turns. Try spinning the motor and let gravity take it's course on the shaft.
 
I'm curious if the "fit" between the tongue and the groove is just too tight to let the gear "set in" correctly at the speed the starter rotates. Tom, I'll try it again with different levels of downward pressure and see if gravity helps any. I'm also considering:
1) adding a splash of oil in the valve chamber and some PB Blaster in the combustion chambers to help keep things moving smoothly,
2) filing the sides of the tongue a little

Thoughts?
 
They had installed it, but it jumped out of position when i tugged out the distributor (which I didn't rebuild) that got bound in the top connection. I must have pulled too hard after installing it too well.
 
are you able to verify that the shaft can mesh with the bottom of the drive assembly? The slot and tongue must not be damaged. I don't remember if the tongue/slot is offset on the oil pump side.
Sounds like the oil pump is not accepting the drive assembly.
time for a flashlight and a mirror.
Bob
 
Bob, The damaged connection between the distributor gear and the pump is the theory I am working with as of my post of the other day. This theory may change. I suspect that the distributor (when it was bound up with the gear/spring and I tried to remove it) may have lifted the gear out of position and "snapped back down" to kiss the the top of the oil pump a little too hard. This may have caused a little distortion of the slot on the top of the oil pump. This theory explains why the connection isn't working. Again, this is just a theory. I stopped by J&M Machine yesterday and discussed this with the guys (I happened to be in the Boston area). They think it is possible that this is what occurred as the metal on the pump shaft is softer than that of the gear and can be distorted if hit.

IF THIS IS THE CASE (and I don't know if it is), I'll find out on Sunday. I have my area's local Model A guru coming over to take a look. If the groove on top of the pump is now slightly distorted, it may be possible to put it back into shape with a REALLY LONG flathead screwdriver and some gentle persuasion. The other options seem to include using a distributor gear with a worn tongue or dropping the oil pan and dealing with the pump "hand on". J&M does not like the idea of using a distributor gear with a worn tongue. For the record, they have been very helpful in the matter.

I'll keep everyone posted.
 
If this is what you think is the case I would be pulling the pump and checking the top of the shaft for cracks. That is just my thinking as I have seen things crack from sudden stoppage and break later at a very unoportune time. Case and point a small plane (Cesna 150) I know of had a prop strike the ground upon landing. The prop was trashed and the hub of the crankshaft was inspected per the manufacturers minimum recomendations and all seemed well. Plane was put back in service. 2 weeks later the plane crashed just after take-off as the crank had broken just in front of the first rod journal. This could have been avoided if the owner would have listened to the mechanic and the entire crank would have been inspected. The owner only wanted to pay for the minimum required inspection. Fortunately no one was killed. Rod
 
Referring to your post #10, I would seriously consider putting a slight bevel on the end of the bottom tang of the drive gear that engages with the oil pump slot. Should not take much with a file. The tangs and slots in the short shaft between the Dist. and the pump drive are all slightly offset and only fit one way. I have had to do some filling to widen and deepen the slots to get a good fit. I know that comes after the drive drops in, just a warning. The bottom tang of the drive is not offset and will fit at either 180 degree position but may need some of the sharp edge taken off to begin to drop in to the oil pump.
Since you think there could be slight damage at the stubborn connection I think it wise to get a long screw driver in through the head, valve cavity and engage the pump to see that it turns freely. Best case scenario would be to make a long shaft the same end configuration as the end of the drive tang but without the drive gear. Many engine builders have these to verify the pump and to pre-lube the engine.This eliminates the guessing. To bad you don't have the early pan that allows removal of the pump without removing the pan. Best of luck.
 
Without a removal of the pan and the oil pump you are guessing.
See what your local guy says, but I would be going deeper now instead of reconstructing a failure later. Those are never good.
Bob
 
Happy to report that a distributor drive gear is now properly seated. John K tried his hand and getting the old one into place. He couldn't. He then decided to compare it with several spares he brought in a box. The spares fit. Apparently the drive i had used a tang that was just too thick (on the bottom where it connects with the pump). The possible peenning of the pump shaft that may have occurred (as previously described) just wouldn't allow the tang/groove to work. John K stated that the replacement gear/drive was another example of a "close but not close enough" part and that they often needs some adjustments. I'll again state that the gear was seated when I got the engine so it must have fit at one point; however the gear was yanked out by my distributor shaft sticking in the top part (which had a tang that was too thick too). Apparently the fit depends on the supplier and not all replacent pieces work together or with the original parts. With 25 hours of figuring out why a 2 minute install wouldn't work, the new (John K's) replacement gear in place I am now ready to button up the valve cover. Photos and videos will follow.
 
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