TI distributor question

[Mike E.]

I am trying to put together a TI distributor from inherited pieces, and have one question.
What retains the magnet/ pickup coil in the proper place? I know it interfaces with the top of the rod from the vacuum advance unit and that the distributor mainshaft goes through the center of it and the toothed piece as well, but is there some kind of c-clip or other device that locks it in place? The clearance between the rotating teeth and the teeth on the pickup coil aren’t far apart, and I don’t want them to get any closer. I do have the large brass washer in the proper place, btw.
FWIW, the pickup coil assembly is good used and tested properly.
Thanks

[Bill B.]

Re: TI distributor question

Hi Mike,

I do not believe there is a retaining clip to hold down the Magnetic pickup coil. The coil rests against the brass washer and rotates around the distributor housing's hub via the Vac Adv Can's shaft. Looks like it relies on gravity to hold it down, but the rotating pole piece above it prevents it from leaving its place should the vehicle encounter a large vertical bump.

There is an exploded view pic in the April 1964 Chev Service News in the TI distributor. I tied to copy and attach here, but looks like it didn't work.

Also, TI Specialty in Richmond, Indiana may be able to provide more detail on this.

[Bill B.]

Re: TI distributor question

Here is a link to the exploded view of the distributor:

1964 Corvette: Service News: Servicing the Breakerless Ignition System (corvetteactioncenter.com)

[Mike E.]

Re: TI distributor question

Bill,
Thanks! I looked everywhere I could think of for a schematic of the distributor, but couldn’t find one. Never thought to look there—and I have that service news downstairs. That helps. Onward and upward from here.

[Duke W.]

Re: TI distributor question

The stationary pole piece is retained to the housing by the same "thin, wavy" C-clip that retains the breaker plate on a single point distributor. I don't know if they're available from GMPD or the aftermarket any more.

BTW, the VAC on a mag pulse distributor can be changed without removing it from the engine just like on a single point. Pump down the installed VAC to the limit, remove the two screws and carefully wiggle the pin out of the breaker plate or stationary pull piece. Pump down the new VAC and install in the reverse order of the removal procedure.

Duke

[Joe L.]

Re: TI distributor question

The stationary pole piece is retained to the housing by the same "thin, wavy" C-clip that retains the breaker plate on a single point distributor. I don't know if they're available from GMPD or the aftermarket any more.

BTW, the VAC on a mag pulse distributor can be changed without removing it from the engine just like on a single point. Pump down the installed VAC to the limit, remove the two screws and carefully wiggle the pin out of the breaker plate or stationary pull piece. Pump down the new VAC and install in the reverse order of the removal procedure.

Duke

Duke------

The spring retainer was GM #1932024. It was discontinued by GM without supersession in December, 1991. I don't know if it's available in the aftermarket.

[Bill B.]

Re: TI distributor question

When I read Duke's and Joe's response, it jogged my memory (or what's left of it) and I went to my archives. I found a pic from my rebuild clearly showing the undercut for a retaining ring. Also found the second attachment in my files as a reference.20190106_112957.jpg

20220426_161425.jpg

I also went out to the garage, and removed the Dist cap & rotor, exposing the rotating pole piece and stationary coil. I could pull up on the stationary coil and felt a "springy" resistance before a short travel to a hard stop, thus confirming that I did have the spring washer retainer installed. When I had the coil pulled up against the stop, I did verify that there was still clearance between the coil and the rotating pole piece, thus, the stationary coil was indeed not being retained by the rotating pole piece.

Thanks Duke & Joe for the clarification. I was much too reliant on that original exploded view in the Service News and my weak memory.

[Mike E.]