HEI Distributor End Play - 1975 L48

[Tommy F.]

I'm in the process of cleaning and detailing the last few loose ends before I get the motor back in my '75 L48. When cleaning the distributor, there seems to be a lot of "thrust" (up and down) motion. I didn't take the time yet to measure the movement, but it is enough that I am concerned. Is there a published spec on this end play?

If it is excess, can the gear be shimmed to take slack out of the shaft?

Thanks,

[Duke W.]

Re: HEI Distributor End Play - 1975 L48

How much end play does it have and how does the vertical alignment of the stationary and rotating pole pieces look at the limits of shaft end play.

Duke

[Martin N.]

Re: HEI Distributor End Play - 1975 L48

TOM-

Is there a washer between the distributor drive gear and the bottom of the distributor housing shaft? End play on these should be listed in your GM Service Manual, I believe. Like Duke said, your rotating pole piece will function as long as it doesn't move too high up. I would think you'd have some distributor rotor wear or hits.

Marty

[Clem Z.]

Re: HEI Distributor End Play - 1975 L48

HEI have .050/.060 end play but do NOT shim below .010 because the aluminum housing will expand more than the steel shaft and could cause the gear to bind to the aluminum housing.

[Tommy F.]

Re: HEI Distributor End Play - 1975 L48

How much end play does it have and how does the vertical alignment of the stationary and rotating pole pieces look at the limits of shaft end play.

Duke

Duke,
Sorry for delay in reply...although I havn't had time to get the dial indicator on it, it takes .097 in feeler gauges to take the slack completely out. There are 2 thin shims on it already. The stator/rotor relationship looks o.k. ( the rotating member is not close to going above the stator ). No excess oil up top, and the case & gear look like new. Leave it alone?

[Tommy F.]

Re: HEI Distributor End Play - 1975 L48

The distributor really looks to be in good shape, no galling or side play in the gear, but the "slop" is .097 +/- using feeler gauges...Rotating assembly looks fine to my eye. I may see about taking .020/.030 out of it...Thanks,Tommy

[Duke W.]

Re: HEI Distributor End Play - 1975 L48

The excess end play will cause spark scatter, so go ahead and shim it up as long as it doens't result in lack of good vertical alignment between the stationary and rotating pole pieces, and follow Clem's advise on minimum end play.

The HEI is a very good and reliable ignition system, but eventually the pickup coil and module can fail. If you replace them now, you will likely never have to worry about the system again. These parts are readily available and inexpensive in the traditional brand names. Like single point distributor parts these brand parts are all likely manufactured by Standard Motor Products.

Duke

[Tommy F.]

Re: HEI Distributor End Play - 1975 L48

Thanks Duke....I'm a safety man at heart, so the pickup /module/coil are all gonna go!
Now the big question....Other than a boneyard, do you think that shims of the proper hardness are still dealer items, or is a trip to the machine shop in order?
Thanks for the help,

[Duke W.]

Re: HEI Distributor End Play - 1975 L48

Mr. Gasket 2820 and Moroso 26140 are two available shim kits. Googling will get you sources and specific kit contents.

Duke

[Tommy F.]

Re: HEI Distributor End Play - 1975 L48

Thanks Duke

[Clem Z.]

Re: HEI Distributor End Play - 1975 L48

Mr. Gasket 2820 and Moroso 26140 are two available shim kits. Googling will get you sources and specific kit contents.

Duke

make sure the shims are hardened,hit them with a fine file to check

[Tommy F.]

Re: HEI Distributor End Play - 1975 L48

Thanks Clem....on the way from Summit...under $5 for a combo kit of fibre and steel washers....looks like enough to make up close to .100 depending on the combo...I'll hit one with the file before installing.
Tommy