1970 Distributor questions

[Jordan S.]

My tach has not been working. I hooked up a drill to the cable at the distributor and the tach worked. Figured it was the cross gear. I disassembled the dist. today and the cross gear and shaft gear look great. There is no nylon or brass button in the housing but the housing looks good as well without any significant wear at the back end. (Solid housing w/o the hole)

Anybody have any ideas about why my tach doesn't work?

Also, the underside of my dist. had alot of orange overspray. The ID band was pink side in and the silver side was almost completely covered with orange engine paint as well. Does anyone know if there shoulde be any overspray or should it be pure black with no paint in the ID band?

Last question. My Vacuum advance reads MS 360 12. Could this be correct for a LS-5 1970? My JM says this is for a l46. If not correct, is it functionally similar to the JM listed 217 16?

Thanks for your help.

[Michael G.]

Re: 1970 Distributor questions

Jordan,
I am in the middle of a rebuild of my 71 350 distributor. Mine has the nylon button and I have read that this was added to eliminate the problem you are having. Another cause could be the brass pushings for the distributor shaft. Enough wear on these could give the separation from the tach drive. Also check the endplay of the main shaft. This would not usually be the cause by itself, but combined with one of the other issues mentioned, it might. Check that there is a small washer (spacer) between the tach cable drive and the tach drive gear.
There was absolutely no orange overspray anywhere on my unit ID band.
Mike

[Joe L.]

Re: 1970 Distributor questions

My tach has not been working. I hooked up a drill to the cable at the distributor and the tach worked. Figured it was the cross gear. I disassembled the dist. today and the cross gear and shaft gear look great. There is no nylon or brass button in the housing but the housing looks good as well without any significant wear at the back end. (Solid housing w/o the hole)

Anybody have any ideas about why my tach doesn't work?

Also, the underside of my dist. had alot of orange overspray. The ID band was pink side in and the silver side was almost completely covered with orange engine paint as well. Does anyone know if there shoulde be any overspray or should it be pure black with no paint in the ID band?

Last question. My Vacuum advance reads MS 360 12. Could this be correct for a LS-5 1970? My JM says this is for a l46. If not correct, is it functionally similar to the JM listed 217 16?

Thanks for your help.

Jordan-----


The GM #1115360 vacuum control is the correct one and the one originally used on the distributor for your application.

[William C.]

Re: 1970 Distributor questions

Check the length of the tach cable as well as the condition of the square at the end. You may be seeing slippage at that end. Would not expect to see orange paint on the distributor originally.

[Jordan S.]

Re: 1970 Distributor questions

Jordan-----


The GM #1115360 vacuum control is the correct one and the one originally used on the distributor for your application.

Thanks Joe.

[Jordan S.]

Re: 1970 Distributor questions

The square end looks good. Do you know what the proper length of the inner cable should be?

[Dave S.]

Re: 1970 Distributor questions

My tach has not been working. I hooked up a drill to the cable at the distributor and the tach worked. Figured it was the cross gear. I disassembled the dist. today and the cross gear and shaft gear look great. There is no nylon or brass button in the housing but the housing looks good as well without any significant wear at the back end. (Solid housing w/o the hole)

Anybody have any ideas about why my tach doesn't work?

Also, the underside of my dist. had alot of orange overspray. The ID band was pink side in and the silver side was almost completely covered with orange engine paint as well. Does anyone know if there shoulde be any overspray or should it be pure black with no paint in the ID band?

Last question. My Vacuum advance reads MS 360 12. Could this be correct for a LS-5 1970? My JM says this is for a l46. If not correct, is it functionally similar to the JM listed 217 16?

Thanks for your help.

Jordan,
Bill Clupper gives excellent advice. I had the same situation with my 70 LT-1 and after cross gear replacement and lots of frustration I found the tach cable was just a little short. Caused it to work some of the time and not others. One time I had my fingers crossed during an OPS check at flight judging. You can buy a cable at any parts store and install it easily.