tach connection in distributor

[Terry Hitch]

Hi Group, Need some advice on a tach problem. When connected it will rise to abt 60 but will not come back down until disconnected. Could this be something other that the gear connection. Also, if it is the gear can I replace without taking the distrib apart. Thank you

[Gerard F.]

Re: tach connection in distributor

Terry,

That sounds more like a problem within the tach, then the distributor gear. There is no physical connection between the tach cable and the tach needle. Just magnets rotating. Maybe the needle is getting stuck at 60, and when you disconnect the cable you jar it enough to have it fall back to 0.

If it were the cable or gear, you would see the needle fluctuating. If it is the gear, you should check both the drive gear. and the one on the distributor shaft. If one is bunged up the other is also probably bunged up.

The drive gear is pretty easy to replace but you'll need to replace the shaft if the shaft gear is bad.

I'd check the tach first.

Jerry Fuccillo
#42179

[Jim T.]

Re: tach connection in distributor

If it is a distributor tack gear problem, the usual kind of problem is destruction of the tack gear and distributor shaft gearing from lack of lubrication. If this has happened, the tack will not operate due to lack of input from the distributors shafts rpms. The removal of the tach gear is not difficult, unscrew the tach cable connector, using a good flat blade putty knife/scraper to fit the brass thing screwed into the distributor housing remove this piece and the gear will come out. Don't loose the washer, clean the brass piece and gear and lubricate with grease. The tack gear failure reminds me of the failure of my garage door opener gearing. The electric motor of my garage door opener turns plastic gearing to open and close the garage door. Due to lack of lubrication the gearing disintegrates over years of use. Learned during the replacement of the drive gearing which came with an ample amount of lubrication, that lubrication is recommended once a year. If we lubricated our gear driven tack drives as a regular maint item like front wheel bearings our tack drive distributors would have the original shafts and tack gear longer.

[Robert S.]

Re: tach connection in distributor

Terry,

I agree with Terry...check the tach first.

I had the same problem after I had my tach rebuilt. I check my distributor gear and cable both new and they were OK. So I spoke with the rebuilder and he said send it back. When he checked and found a speck of metal on the magnets. He cleaned it up and now it work perfect

Bob