C2 tachometer gear replacement ?

[Rod M.]

I ordered a replacement tachometer gear assembly for my 66 327 and there was a small brass button included. when I removed the old assembly there was no button to be found. additionally the button has a small shaft on it and I do not see a corresponding hole in the distributor. There is no mention of this in the AIM so my question is what to do with the button? Do I put the new assembly in without the button?
Any help would be appreciated.

[Peter J.]

Re: C2 tachometer gear replacement ?

Later model improvement, 67 I think? I don't have it in my late (June 22nd) 66
car either

[Dick W.]

Re: C2 tachometer gear replacement ?

Someone has added it to compensate for wear on the housing. We used to do that on most of the distributors that we rebuilt

[Rob M.]

Re: C2 tachometer gear replacement ?

Rod,

Peter is correct (I believe) and if Dick rebuilt your distributor in the past and you didn't know it, you could replace it Otherwise, rebuild it without it - I did and all is good.

Good luck,

[Timothy B.]

Re: C2 tachometer gear replacement ?

Rod,

The brass button you are seeing is made for the wear in the distributor housing where the tach gear rides. When the engine is running, the tach gear thrust is inward and the gear wears the housing. After the gear becomes misaligned with the mainshaft gear it wipes itself out.

If you check the archives there is discussion about procedure to repair this area, it's worth reading before you start. You can repair this at home if you are careful using the brass button to provide a new wear surface for the tach gear.

It's also a good time to clean the distributor and inspect/lubricate the advance mechanism.

[Jim T.]

Re: C2 tachometer gear replacement ?

Later model year distributors came with a hole drilled in the distributor that the shaft of the button would fit.
I have read on this discussion board that the hole in the distributor stated in 1970. My original owner 1970 built in July does not have this drilled hole in the distributor.

Another maint you can perform is to remove the plastic seal at the top of the distributor and clean out the crud and install new lubricant. The plactic seals may still be available from GM. There are several in the sealed package.

Check the archives for postings on which lubricant and packing you want to use.

Dave Fielders web site has excellent information on how to rebuild/lubricate a distributor. www.tispecialty.com click on articles

[Rod M.]

Re: C2 tachometer gear replacement ?

I found the article from TiSpecialty very helpful. I plan on pulling the distrutor and installing the button if need be. Thanks to everyone for the help.