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Distributor plate replacement


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I'm trying to replace just the distributor plate  on the driver's side of my 1940. The one currently on the car seems damaged. I have a NOS replacement. I can easily remove the distributor cap, but removing the plate seems to be more troublesome. What advice can I get in regard to pulling the plate off? I'm hoping I don't have to remove the entire loom on that side of the car.

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The distributor plate is just fitted on the side of the distributor and has 6 spark plug wires attached on each side of the distributor.  They might seem 'glued' on, but they should come off with a gentle prying.   If you have NOS replacements or the newer rebuilt ones I would install them.  If you're careful when you get the plate off the side of the distributor you can see exactly where each plug wire is inserted.  You can replace them one at at time or carefully mark them to get them back to their proper hole plug or it won't run!  If you notice there are numbers on each plug of the plates on each side as to the corresponding spark plug number position.  Carefully unplug each wire and insert it into the new plates and the reattach it to the distributor.  Make sure it's locked into position on each side of the distributor.  This would also be a good time to replace the spark plug wires (7mm) if you have the ambition!    

 

 

 

 

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Thanks.

The trouble I'm having is getting the plate away from the cap itself. It only seems to pull out about an 1/8th inch or so. I supposed the plug wires are preventing the plate from coming out any further, so I suspect I'm going to have to remove the whole loom on that side. Not an easy job, since the generator has been replaced by an a/c compressor. The bolts holding the loom are hidden underneath. Just wanted to make sure I wasn't missing doing a  procedure as I tried to pull off the plate away from the cap.

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Nothing can challenge your ambitions on these cars like getting down to the problems that need attention.  Yes, those conduits that hold the plug wires are challenging.  If you have them off the car best to renew them as you don't want to be doing that job very often.  Those wires are 7 mm and are available from different sources,  They need the insulation of the 7mm sizes, but getting 6 of them in those conduits can be challenging.  I have found that if you mark and pull out the old cables, then cutting new ones to length is the easiest.  They mostly need to go in individually, but with a little silicon lube on them they tend to cohabitate easiler.  Just be careful around the distributor with the bakelite plates as they are brittle and will crack.  Someone does rebuild them.  I got a set some time ago when I redid the distributor the last time.  Biggest problem I was having was the gap between the rotor and the pins on the plates.  There needs to be no more than .010 gap so the spark doesn't have to jump so far.  So new or rebuilt rotor and plates are important for the best performance.  Good luck with it!!

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  • 1 month later...

I just learned that the "O" ring pops off, and the piece that appears to be a fastener, is not really a fastener, but part of the distributor cap. I don't know why that didn't occur to me. It just looked too much like a fastener to me. 

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I think I may have found the problem I've been having in regard to the car stumbling and hesitating upon acceleration: While I was replacing the distributor plates, I noticed that one of the distributor cap locating tabs is broken, allowing the plate to freely rotate slightly when put together. Am I correct that this would cause problems? And.... where do I find a replacement cap?

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West that alone would not account for a miss or stumbling. The missing tab can allow the outer cap to rotate and pull one or more wires from their seat in the inner cap. The outer cap has nothing to do with timing or spark control, it is just protective.

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This thing is going to fight me every step of the way. I for the life of me cannot seem to get the new plates to fit all the way onto the distributor. It seems that they are a hair too large. Or??? My lack of knowledge is getting in the way again. I'm aware of the tab, and that seems to be positioned properly. 

 

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It has been a long time since I worked on an 1937 Ford V8 Distributor for a friend. I remember them being a bear to get back together too. From your photo, are the two marks on the distributor caps supposed to line up with the marks on the distributor body? They look close, but a bit off.  

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The plates have a 'lock in' tab on them so they fit snugly on the side of the distributor.  Just carefully rotate them till they lock into position and put the spring retainer in place an you should be good to go!   Once they're locked in place they won't rotate.    That way they line up with the rotor operations to fire all 12 plugs synced into place!

 

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West, both the NOS and NORS inner plates will swell some with storage or were made oversized. I don't know which it is.

 

I trial fit mine before I put in the  wires. If they do not fit, I use my belt sander to carefully shave off some of excess.  Make sure that you maintain as much of the roundness as you can. Try each cap in both sides of the distributor as a cap may fit in one side and not the other, due to casting tolerances.

 

I am sorry that I did not mention that before, but it is automatic for me and I just did not think of it.

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