Remove Bosch Distributor Gear Pin

[Jolls]

Hi Team,

Todays project is the a distributor. I almost have it stripped down but am stuck at removing the distributor drive gear pin. My efforts to persuade it out so far have been unsuccessful. The pin in the manual appears to be a straight pin and the manual simply says to knock it out. The head of the pin on both sides is rounded so I am wondering if someone previously has peened them to ensure the pin and the gear stay put. Was peening them over a normal practice?

My plan is the grind one end and then tap it out; however, I thought that before taking that step I would seek the wisdom of the forum; perhaps, I am missing something.

Any and all advice would be greatly appreciated.

Cheers n Beers
Jolls

[DougT]

Hi Craig, it should just be an interference fit no peined over ends.

Doug

[ardiesse]

Craig,

The manual is lying at this point.  As far as I can tell, the pin is inserted, then staked in place with a Big F. Press.  You'll have to drill the pin from each side with a 1/8" or 9/64" drill, at least to the depth of the drive gear, possibly more, and then drive the remainder out.

Mark the shaft and drive gear for correct alignment before disassembly, on account of the gear having 13 teeth (go figure!).

When reassembling, use 3/16" diameter steel rod.  I make the pin about 1 mm longer than needed, and use a vice to peen the ends over.  You'll notice that the holes in the drive gear are closer to 3/16" diameter, but the hole in the distributor shaft is 5 mm.  Guess which parts were specified by Germans, and which by Americans . . .

General Distributor Reconditioning Hints:

There's a thin Bakelite sheet on top of the advance weight plate.  It always breaks and moves out of place.  Clean everything up properly and Super-glue the remnants onto the weight plate.

Between the drive gear and distributor body is supposed to be a Bakelite washer, about 0.015" thick from memory.  These also fall to bits, leaving the distributor shaft with too much end float.  Generally, I cheat with a steel washer, reamed and trimmed to size, then "enthinnened" to suit.

You can, if you're brave, recondition the advance weight pivot pins with a MIG welder and a file.  You need a deft touch and some bearing blue.  Similarly, you can shrink the holes in the advance weights using a centre-punch and care.  If the slot in the advance weights is flogged out, you can narrow it down by using a vice.  3/16" ID fibre washers are ideal to put between the advance weights and the shaft plate.

Check the fit of the distributor cam on the shaft for looseness (side-to-side).  If too sloppy, find another distributor to recondition.  Or change to a Pertronix module (no points).

Check the fit of the two halves of the breaker plate.  If there's side-to-side slop between the two halves, you can usually bring it back by expanding the swaged part of the upper breaker plate over something like a tapered reamer.  Or the right size Morse taper.

Vacuum advance units suck.  No, seriously.  Apply lips to the pipe union and suck.  If good, the diaphragm will retract and stay there if you block the opening.  I think there's a guy in Qld who reconditions vacuum advance units.  Check that the earth braid is present and in good condition.  If it's missing, replace it with small-size desoldering braid.

Best of luck.

Rob

[Jolls]

Thanks Rob and Doug

Really appreciate the advice and guidance.

The ends of the pin were definitely peined over. I drilled the ends - no movement. I drilled though the pin with a small bit and then progressively enlarged the hole and tried to persuade the pin out after each time. Got it on the fourth go.

Bakelite washer is in several pieces with bits missing.

After cleaning off as much as I could of 65 years worth of oil and dirt most parts look OK. Quite tight actually.

The advance weight pivot pins also look pretty good. I have it soaking in parts cleaner so I can get through the crud and see what I'm dealing with.

I think the previous owner also owned the bypass oil filter I purchased. It has as much caked on and encrusted oil and mud on the outside as the 1 1/2" of semi solid goo on the inside of the filter.  I had to knock the big pits off with a large screwdriver and ball pein hammer. The distributor attached to the engine is in much better exterior order; but it can rest in place for a while yet.

I take it from your advice Rob that parts will be a problem. I may have to come up with a novel solution for the bakelite "washer"; I don't think susperglue is going to save us.

Cheers n Beers

Craig

[my8thholden]

Hi Jolls ..There might be some fabric impregnated resin sheet in the museum workshop where I volunteer , they use it in magneto's , not sure of the thickness ..i'll have a look next week ...I know there is fair amount of shim brass sheet ..Vern ..

[Jolls]

Hi Jolls ..There might be some fabric impregnated resin sheet in the museum workshop where I volunteer , they use it in magneto's , not sure of the thickness ..i'll have a look next week ...I know there is fair amount of shim brass sheet ..Vern ..

Hi Vern,
Thanks for the idea. I will start searching to see what I can find. I have been trying to think of where I would find thin bakelite to replace what little there was left. That could be why she was in a parts pile - not working because of an interanl short circuit. Apart from that it is a very tight unit for something 65 years old.

[fcee]

 brand new electronic grey motor distributor on ebay 976-n 109 dollars    cheers Steve

[Jolls]

brand new electronic grey motor distributor on ebay 976-n 109 dollars    cheers Steve

Hi Steve,

Thanks, I have been watching them. I assume I need a specific coil to to with it. I will still try to bring this old girl back to life.

Cheers
Craig

[fcee]

 Craig I fitted  a petronix electronic ignition module to my bosch distributor about 5 years ago and used the original coil ,worked fine ,but later added the petronix coil . opened the plug gap to 32 thou and now the car starts instantly on the first revolution. can recommend this mod .cheers Steve 

[Jolls]

Craig I fitted  a petronix electronic ignition module to my bosch distributor about 5 years ago and used the original coil ,worked fine ,but later added the petronix coil . opened the plug gap to 32 thou and now the car starts instantly on the first revolution. can recommend this mod .cheers Steve 

Now that is the right direction to be heading - thanks so much. It soulds like the way to go - I will look into it in more detail.

Cheers n Beers
Jolls