63 Tach Drive Distributor - Part 3

[Stuart F.]

Now that Christmas has finally wrapped up, I am finally able to spend a bit more time on my Distributor project;

After closer inspection of the main shaft and the main shaft bushings, I have discovered that the scoring on the lower part of the shaft is all above the bushing! The bushing is in perfect condition with no indications of damage. I can not figure then how the shaft got damaged except perhaps the tach drive cross shaft wearing in the housing produced grit big enough to scratch the shaft. There are no teeth broken off either gear. Any ideas?

The old shaft actually looks better than the new one I just received. The original braze job on the football was much better. The only thing in favor of the new shaft is that the tach drive gear mics in about .005" larger than the original which has worn I guess. Ironically, the original cross shaft gear shows no wear (mics the same).

I have been able to do a good drill and tap operation to install a limit button. On this I have a question also;

NOTE: The instructions called for drilling a 13/64" hole to tap a 1/4 - 28 NF. This would not work for me, rather most newer taps call for a NO. 3 drill and this worked like butter.

The new cross shaft is of the so called "improved" version. It has a bronze end button. My question is; will it be ok to use this with/against the bronze limit button, I.e. Bronze against bronze?

(My original had a hard steel end button with a dimple in the center).

Stu Fox

[Timothy B.]

Re: 63 Tach Drive Distributor - Part 3

Hi Stu,

Merry Christmas to you, if I understand your post the threaded portion tapped into the distributor is some sort of brass set screw that mated with a new cross gear that has a brass button installed into the end of the gear, the end result is brass on brass.

I can't answer your question as I always use the factory gear and just install the little bronze button. I see no reason why you need to change your original main shaft or driven gear if there is no damage. The original mainshaft football should be stamped #54 and the weight base cam should be stamped 724. The only thing I would do to the curve is install some light springs to get the curve in at approx 3000rpm. and be careful you don't loose the original springs.

It's hard to say what caused the scratch on the mainshaft, don't over think it and cause lots of work for yourself. If you have tapped the housing for a set screw you can go to the Home Depot and get a steel set screw with some blue loctite and use all the original parts. It probably will not wear out in our life time, lets see what other suggestions get posted.

[Stuart F.]

Re: 63 Tach Drive Distributor - Part 3

Thanks Tim. My numbers check out exactly as you state. I have now both a new shaft and cross gear, but my thought now is to save it for my heirs, or return them for some "eat out" money. The tap job went well once I had the right tools. The brass button fits flush in the housing as you recommended before, and I have a set screw and locktite. The only reason now that I might want to use the new cross shaft is the square tach cable hole in the original one is sort of rounded out, and perhaps the new parts might steady my tach needle some at idle.

Stu Fox

[Gene M.]

Re: 63 Tach Drive Distributor - Part 3

I have not done the set screw deal. I assume you do this to control end play of the tach gear. I just shim the button my grinding it's thickness. But you need to start with a thicker custom button.

[Stuart F.]

Re: 63 Tach Drive Distributor - Part 3

My last technical question on this thread for the year;

Can I use a new tach cross shaft (improved version) which has a brass end button together with a brass thrust button in the distributor??
(call it brass or bronze, brass to brass)

Stu Fox

[Stuart F.]

Re: 63 Tach Drive Distributor - Part 3

Happy New Year y'all!

Finally have my distributor back together to the point of installing the tach cross shaft with the new thrust button. Basically it is a no go. The cross shaft seats tight on the button long before the coupling is tight. So far, I have to say, none of these new repro parts work worth a darn - certainly not as advised and promoted by the vendors. I do not want to grind down the button, and shouldn't have to. The button measures about 3/32" thick.

I have ordered a pack of the "plastic" buttons from LLC and will try to use one of them.

Well, hope not to spend too much of 2015 on such simple projects.

Stu Fox

[Stuart F.]

Re: 63 Tach Drive Distributor - Part 3

Just in summery; I finally finished my distributor project. Here are som observations:

I was not able to use ANY of the after market parts except the set screw. I concluded I did not need a new shaft or new bushings. I could NOT use any of the new parts, including the new cross shaft, coupling or any of the thrust buttons (bronze, brass, Nylon or plastic)!! They will not fit in my 63 housing with or without a set screw. I believe TIM B. Was spot on when he said you have to mill a 1/2" or larger area for the button to fit flush in the housing. None of the vendor instructions are correct.

I hope it will work, but I had to end up using my old cross shaft gear with steel end being restricted in end travel by my new steel set screw. I used locktite on both the set screw and cross shaft coupling after I run in the screw and backed it out 1/4 turn for clearance. I used a new main shaft drive gear that I have had laying around since the 70's, and shimmed it to .016".

Start up was fine, but I still have tach needle bounce at idle as before. At least it is running.

Stu Fox