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MG MGB Technical - re-manufactured distributor trobles

Just recieved my re-manufactured 25D distributor from Victoria British today and tried to install it and come to find out it dosn't want to go into the engine it feels as if the shaft is just a little bit thicker than the original. All markings on the new distrib look to be the same as the original.
Thomas Strombeck

Sorry to hear about your troubles - so close and yet so far...

You can try freezing your new distributor to shrink it slightly. That might allow you to install it, but it may never come back out. The same thing can be said for thoroughly cleaning the distributor hole on the block.

Try taking a large wrench (maybe an adjustable wrench) and sliding it over the largest part of the distributor shaft. By rotating the distributor you should be able to tell if the body is out of round or distorted in any way that would prevent installation.

There are lots of threads about rebuilt distributors in the archives too. I couldn't find any that mention this problem, although several commented on distortion from over tightening the clamp. I remember mine fitting very tight as well, but I rebuilt my stock unit rather than getting one that came from who knows where. Sorry I'm long winded.

Jeff Schlemmer

Thomas. A set of dial calipers costs under $25 for a stainless steel, 6" model. That should tell you what the diameter of the outside of the body is. If you still have your old dizzy, you can compare. If you do not, post your measurements and I will measure some of my spares and see how they compare.

There are, actually, three parts to this system. These are the distributor body (the distributor to most of us), the distributor clamp and the distributor housing. The distributor housing is the part that fits into the block, held by a single screw. The distributor housing both receives the distributor, holds the distributor drive gear in place, preventing it from moving upwards, and has the holes for the distributor clamp.

Now, the way to trouble shoot this problem is to first remove the distributor clamp from the engine. Then, try to insert the distributor into the distributor housing. If it fits, the distributor body and housing are good. This leaves the clamp as the problem. (And, this is the most common problem I have found when changing distributors.) Back off the nut on the distributor clamp, spread the jaws with a large screwdriver, assemble the clamp to the distributor body, then assemble the clamp and distributor to the distributor housing. Assemble the two hold down bolts for the distributor clamp, then, snug the clamping bolt down until the distributor will just move with some drag on it. Set your ignition timing, then tighten the clamp bolt nut until the distributor will not move freely. Les
Les Bengtson

As an aside...I avoid buying mechanical bits from VB ever since they couldn't answer tech questions about something simple I bought from them. Nice folks, honest and all but not very technical.
J.T. Bamford

O.K. I'm getting closer. Put grease on the drive and worked the daylights out of it and it now fits. Snug but it fits. The current problem is that it won't go in the final 1/8 to 1/4 inch. I've pulled the colar sleve clamp and fitted it to the distributor directly, but it still won't go in the last little bit. I've set the car up to be on TDC with piston #1 it the top but this still isn't working. Sorry for being a pain, but this strating to get just a little furstrating. Tom
Thomas Strombeck

O.K. I got it put together! Runs much better. But now the clutch is starting to go. I can really tell when I'm in 4th. Boy if it's not one thing it's another. BTW anyone out have a brake master cylinder for a 74 CB they would like to part with? Thanks for all of your help. This is one of the greatest groups of people I know. Tom
Thomas Strombeck

Hello Tom,


Today morning, exactly the same misadventure happened to a friend and me: we attempted to reinstall a Lucas 25D
dizzy ointo a TR3 car. The clamping plate was too narrow to allow dizzy body to slide in and down correctly. Just slide a large screwdriver blade to enlarge it and it's all right . Help that help . Regards .
Renou

Tom, I'm glad to hear things are working out! If you want that clutch plate I mentioned, its all yours. It probably has 300 miles on it. I have a few centering tools lying around as well.

Jeff Schlemmer

Not the same problem, but beware.
I had a customer bring me a B with a rebuilt distributor from some american rebuilder, bought at a regular parts store. It had a sticker of a major American rebuild association. It was marked (original marking)as the correct item for the car, however:
the mech advance unit was not anywhere close to correct
the vac unit was wrong
the screws retaining the point plate were too large and too short, holding only by a slight interference fit, not threads.
there was no plate ground wire.
When spun, the plate jumped up and down rather than opening the points.
It looked as if the parts were all thrown in a pile and picked at random for the build up, so I expect that any Lucas dist. from them will be similar.
I don't know where these are made or sold, but they are in the system, and I have read of another case of the same thing happening on the same dist #. Based on an alternator I saw, the VB dist. could well come from the same source.
FRM
FR Millmore

My 72 MGB did not have its original distributor when I bought it. Found a rebuildable one on Ebay for $10 and sent it to John Twist for a rebuild. It works great, and I got to talk to the man who did the work.

Better a known quantity than one unknown.

glq Greg

This thread was discussed between 28/04/2004 and 01/05/2004

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