distributor question
 

Attachment 606416

Attachment 606417The gear in the pic is 1-5/8" long. There is about a 1/8" space or Play in the shaft at the gear. Is that too much, if so can I use washers to fill the space?
Also the bottom of the shaft is 1/4" up inside the gear. Is that correct?
Thanks, Dave

Yes, depending on your installed in the block play with a gasket in place 1/8” is a little much.

You want only .030” of installed play, but you need to use hardened shims or hardened washers to reduce the play.

I would not trust the ware property’s of a common grade 5 washer unless I had a lube hole drilled in the oil galley plug in front of the gear.

Also yes the shaft should be up in the gear since it’s the gear that keeps the upper part of the pump drive shaft contained.

Also the gear goes on the shaft such that it’s up against the dizzy body.

why do you have it on upside down?Tom

That’s the 64 thousand dollar question right there.

When I was fourteen I helped out a mechanic at his shop to learn things.. I did this assbackwards deal on a Chevy distributor and the mechanic quickly showed it to me and explained to me why the proper way was the way it is. Never forgot that. I sometimes think a person learns better from a mistake that is caught than luckily just happening on the correct way first time out.
FWIW

I have no answer for that other than I had a VERY senior moment. LOL:(

Thanks ev1

With the gear mounted the right side up you may hav a perfect up and down play.
Do NOT shim to a silly tight play, you may end up with glitter in oil from the oli pump cover.
I have a NOS 1111078 with .043" play, i would not like to see tighter than that in an iron distributor.
I also have a NOS 1111148 distributor with .070" play as a reference for aluminium distributors.

FWIW

They do make hardened shim kits just for this if one wanted to shim it.
As mentioned don't use soft washers.

Just a thought - these are helical cut gears, and based on the direction of rotation, the driven (distributor) gear will be pushed upward against the shims/distributor body and effectively taking up any slack. I read a lot of comments where people wonder why there seems to be so much clearance from the factory on the distributor gear to body. I see comments about making this clearance tight to eliminate timing fluctuation during deceleration? This makes no sense as the gear will remain pushed up tight against the shims at all times due to the substantial (and constant) load of the oil pump. Perhaps the true purpose of the shims is to set the distance from the gear to the distributor block flange so that the gear has proper mesh with the cam gear? Just a thought.

And achieving more then adequate engagement of the the pump drive shaft into the bottom of the Distributor shaft.

It's interesting to note that Oldsmobile V8 distributors rotate the same direction as Pontiac, but the helical gear is cut with the opposite slant so that the distributor gear is pushed down during operation. There were no shims on an NOS mag pulse Olds distributor that I bought a while back. They have a pad in the block that supports the bottom of the gear during operation.