TheSamba.com :: View topic - How Do You Tighten the Distributor Clamp Bolt?

Sat Aug 16, 2025 10:35 am

When my starter failed I found out that the distributor clamp bolt was loose. This was discovered when I pulled the cap and the distributor rotated a few degrees. I have set the static timing but am unable to tighten the clamp bolt. The YouTube videos I have watched make it appear that the bolt is captive, whereas mine is a bolt that runs through the clamp and there is inadequate clearance on the end of the bolt to fit a wrench or socket. Have others run into this issue and is there a dogleg wrench specifically for this task? I have set the static timing several times, but while the car starts, I can't maintain an idle, and when I recheck the timing it is off again. Car had a good warm idle before this.

Sat Aug 16, 2025 1:10 pm

Finally found the right collection of sockets, extensions, etc, to get the nut off of the hold down clamp bolt only to find that the bolt was stripped. I was able to put a couple of washers on the bolt to allow me to tighten the clamp. I set the static timing using a voltmeter, but still can't get the car to idle. I know that it wasn't replacing the starter that caused the problem, and likely figure it has something to do with the distributor timing, but much like a contestant on Chopped, I am out of time and won't return to the car until November. Any suggestions for troubleshooting the idling issue would be appreciated.

Sat Aug 16, 2025 1:37 pm

The nut and bolt are 10mm.

Sat Aug 16, 2025 7:22 pm

The clamps are often bent from being overtightened. Once overtightened, they don’t hold the distributor securely. Find a good used one that hasn’t been abused and has a good straight nut and bolt. Do not buy brand new reproduction clamps.

Sat Aug 16, 2025 9:07 pm

tasb is correct.

The nut usually sits against the clamp edge and that prevents it from turning but I've had a few that were tweaked or the clamp edge "stripped" (worn out) so the nut would spin.

Sun Aug 17, 2025 1:47 pm

If you restored distributors you’d find more than a few. I’d say a good 25% of the time the clamp is warped and the bolt is bent. Snug people, snug, is all you need.

Tue Aug 19, 2025 6:59 am

Any idea of the bolt to be used? M10 x 1.25 x 70mm?

Tue Aug 19, 2025 9:51 am

It is NOT M10. That is HUGE. A nut and/or bolt that uses a 10mm wrench is most likely M6.

I will go out to my shop and find a distributor clamp bolt and nut and measure it.

Olli

Tue Aug 19, 2025 10:05 am

The one that I measured is; M6-1.0 x 30mm.

Olli

Wed Aug 20, 2025 5:25 am

Thanks!