Subject: [Mg-t] TD distributor rebuild

From: Richard Lindsay <[email-masked]>
Date: Mon, 27 Apr 2015 12:32:18 -0500

Hi Friends,

Today I reassembled the TD's distributor. Here are the springs some PO
had installed. Sorry about the soft focus.

http://aubard.us/MGTD/HPIM1807.JPG

Another List member noted that the drift pin at the drive gear was WAY
too long. Another bodge.

http://aubard.us/MGTD/HPIM1801.JPG

Well, that's all fixed now. Here is how the centripetal advance looks now.

http://aubard.us/MGTD/HPIM1810.JPG

And with the breaker plate reinstalled with new contacts and a new condenser.

http://aubard.us/MGTD/HPIM1811.JPG

http://aubard.us/MGTD/HPIM1812.JPG

And in this last photo, one can see that the stationary contact needs
a little realignment. Gap/dwell, has not yet been set.

http://aubard.us/MGTD/HPIM1813.JPG

A word now about the drive gear replacement. First of all, the old,
over-sized pin drove out just fine but the shaft had to be drifted
from the gear. With that out, the rest of the moving bits were easily
removed.

http://aubard.us/MGTD/20150427_094115.jpg

The plastic disk that rides on the bushing, at the base of the advance
mechanism, is undamaged and is reused. Same with the steel and
phenolic washers at the base. Everything looked great so assembly
began.

First up, I made sure there was no lateral movement between shaft and
bushing. All surfaces were smooth, so I re-oiled the shaft and slid it
home. I put the two washers on the shaft and trial-fitted the gear. It
went on with only minimal encouragement. However, when pressed fully
home, there was about 0.5mm misalignment between the holes. I inserted
a drift pin into the hole and snugged the gear against the washers.
Still misaligned AND binding. This was not going to work without
modification.

I re-examined the pin hole misalignment and using that eye-ball
measurement, I machined about 1/4mm from the gear flange. Closer but
still not enough. I carefully machined another 1/4mm from the flange
and trial fitted. Voila! Excellent alignment. I then started the new
pin, enough to engage both gear and shaft. The shaft still turned
freely and with no measurable end float. I then drifted the pin fully
home, checking for free rotation and run-out after each careful hammer
blow.

That's where it is right now. I'll next realign the contacts then set
the gap. THEN it will be time to go back on the car. A report on that
later.

-rick
______________________________________________

[email-masked]
Archive: http://www.team.net/archive

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From: Douglas Ormrod <[email-masked]>
Date: Mon, 27 Apr 2015 21:36:54 +0000

pleased see the USA is finally moving in the metric direction - 1/4mm is at least half way there :-)

Douglas in New Zealand

I re-examined the pin hole misalignment and using that eye-ball measurement, I machined about 1/4mm from the gear flange. Closer but still not enough. I carefully machined another 1/4mm from the flange and trial fitted. Voila! Excellent alignment. I then started the new pin, enough to engage both gear and shaft. The shaft still turned freely and with no measurable end float. I then drifted the pin fully home, checking for free rotation and run-out after each careful hammer blow.

That's where it is right now. I'll next realign the contacts then set the gap. THEN it will be time to go back on the car. A report on that later.

-rick

[email-masked]

[email-masked]