Help!!! Mallory Zb distributor housing weld repair

[SkylarknMerc]

Hey guys, Today I made an attempt to disassemble and clean my Mallory ZB distributor.
I was able remove the breaker plate and counter weights and thats it.
I got stuck at removing the pin on the distributor drive gear.

While I was trying to punch out the pin , the distributor was wrapped in a rag on a bench vise. I removed it from the vise to change the plan of attack when I noticed the case broken. 😮www.jalopyjournal.net💨

Can this be welded or brazed?

[petehoovie]

Originally Posted by SkylarknMerc

Hey guys, Today I made an attempt to disassemble and clean my Mallory ZB distributor.
I was able remove the breaker plate and counter weights and thats it.
I got stuck at removing the pin on the distributor drive gear.

While I was trying to punch out the pin , the distributor was wrapped in a rag on a bench vise. I removed it from the vise to change the plan of attack when I noticed the case broken. ��www.jalopyjournal.net��

Can this be welded or brazed?

[petehoovie]

D. F. W. I. !!!

[Gene1949]

I doubt if it can be saved. Don’t let anyone fool you, too many variables.
I would suggest you hang it on the wall and show it off as a learning tool/what not to do.
I can't imagine anyone grabbing onto the body of an aluminum distributor and trying to drive a roll pin out of the shaft and gear.
Lot of help on this board, just ask. I usually find a scrap piece of 2x4 and cut a 45 ° grove. I place it UNDER the gear and drive the roll pin out

[mcgarrett]

Do a search for someone in your area that does high tech welding repairs. Assuming that the distributor body is aluminum, there is a new laser welding process on the market today that might mean it could be repaired in the hands of a pro. Depending on what value you put on the Mallory, it might be too expensive to repair it, but I'm not sure what the cost would be. The laser welding process is more sophisticated and less invasive and produces less unwanted heat from what I'm hearing. Could be worth investigating.

[vincent]

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Laser welding is your solution if you cannot machine it. If you have a lathe you could turn the diameter down and make shrink fit replacement.

[Ronnieroadster]

The housing is cast aluminum it can be repaired by a competent tig welded with a little bit of work. In the location of the break thankfully there's no bushings its just an open tube.

The repair is simple first you "V" the edges of the break this gives depth to where the weld is located. You then use a steel shaft the same diameter as the upper and lower bushing diameters placed in the bushings as the alignment fixture.
If a shaft is not available the shaft from the distributer can be used as the alignment fixture. The tig welding is done a little at a time spot welding at three equal locations first so there's minimal alignment distortion. Then gradually the welding continues between the three spots until the entire area is now welded. Once the entire area is welded the bead of thew weld can be removed using a lath or carful hand filing.
Ronnieroadster

[alchemy]

It would need new bushings installed and reamed too, right guys?

[mcgarrett]

Maybe not if the repair is done by a skilled welder.

[SkylarknMerc]

UPDATE PROGRESS REPORT:
I was able to get a coworker seasoned welder to do the repair.!

Looks pretty good as far as the weld and structure.

I found a piece of round stock that fit perfectly snug in the I.D.
Of the case, and used it to keep the stem true and straight.
Worked out great.

Now for the Weld, I'm going to wait on grinding down the weld
until I'm ready to install. I don't want to remove too much material
and grind away the weld. I want to see if I can clear off just enough to
fit in the bore trying not to compromise the weld .
Now the next order of business is removing the stuck Vacuum Brake plung0er

[mfirth]

Nice !!! Glad you could save it. I had one a few years back & couldn't find points 4 it so went back to stock setup.

[tubman]

That looks like a good repair. When you consider that the distributors with the extended lower shaft have a much shorter upper support surface, that should be more the enough.

Mike : The points for these (Mallory # 24875B, I believe) show up on eBay all the time. In addition, I have found an equivalent Echlin set from NAPA that will substitute in a pinch. In the alternative, I will take the distributor off your hands for a good price (if you still have it).

[mfirth]

Originally Posted by tubman

That looks like a good repair. When you consider that the distributors with the extended lower shaft have a much shorter upper support surface, that should be more the enough.

Mike : The points for these (Mallory # 24875B, I believe) show up on eBay all the time. In addition, I have found an equivalent Echlin set from NAPA that will substitute in a pinch. In the alternative, I will take the distributor off your hands for a good price (if you still have it).

Denny, sorry but I gave it back to the guy I got it from, & he has since passed away. Lots of good stuff just vanished with his passing.

[Ronnieroadster]

Congratulations Just as I wrote above a simple fix when the person welding the cracked area correctly knows what they are doing.
Ronnieroadster

[leon bee]

This is good news!

[Bored&Stroked]

If they V-ed out the break area (which I'm sure they did), then you should chuck the housing in a lathe and accurately remove the extra weld material.

[Tim Ayers]

Originally Posted by Bored&Stroked

If they V-ed out the break area (which I'm sure they did), then you should chuck the housing in a lathe and accurately remove the extra weld material.

This. I would try to remove this way vs. grinding it away

[glennpm]

"Quote:
Originally Posted by Bored&Stroked View Post
If they V-ed out the break area (which I'm sure they did), then you should chuck the housing in a lathe and accurately remove the extra weld material.
This. I would try to remove this way vs. grinding it away"

I don't understand the need for this grinding/cutting. The housing is mounted statically. As long as the weld doesn't interfere with installation, I'd leave it alone.

[hueyhoolihan]

Originally Posted by glennpm

"Quote:
Originally Posted by Bored&Stroked View Post
If they V-ed out the break area (which I'm sure they did), then you should chuck the housing in a lathe and accurately remove the extra weld material.
This. I would try to remove this way vs. grinding it away"

I don't understand the need for this grinding/cutting. The housing is mounted statically. As long as the weld doesn't interfere with installation, I'd leave it alone.

ya, i would think that it just needs to slip in and out properly. not that turning it down with a lathe wouldn't be a proper way to do it.

[Bored&Stroked]

The other thing the lathe gives you is the ability to put a dial-indicator and check to see if the end bushing bore is in alignment with the housing OD.

In almost all cases (even with proper setup) welding distorts/moves things. You may need to over-bore the end bushing in the housing and make a new custom bushing to ensure the bushings are running true to the same center axis.