Anyone rebuilt a late model 24V starter switch?

[ashyers]

Hello All,
The starter is having issues and I'm pretty sure it's the switch contacts. After sitting for a few days it won't start on the first stomp, there's poor contact. After some coaxing the starter gets going and all's well. There are no issues until the truck sits for a couple of days. I suspect the contacts in the switch have some grunge on them and likely need adjustment. I was hoping one of you has cracked one of the switches open and may have some advice, or even better, photos!

I'm going to pull the starter this afternoon and take a look.

Thanks,

Andy

[RCrombie]

From what I remember, the contact is made with a large copper disc that lowers onto two posts. These can be cleaned, or the disc can be rotated if necessary to expose a fresh contact area. This is going by memory, and I don’t know what vintage of 24v starter this was.

[ashyers]

RCrombie,
I figure it's like you said. My fear is popping it open and busting/launching the magic snap, gasket, spring, e-clip...

The info in the manuals is essentially remove and replace.

I guess if I tear it apart I should take photos

Andy

[sturmtyger380]

I have cleaned my starter contacts and they work good for a number of years. What happens is carbon builds up on the contacts. When that happens you have to close the switch for a number of seconds until the electricity can overcome the carbon. Eventually it gets so bad it just won't work.

[RCrombie]

I’ll take a look at my parts manual when I get home and see if it has anything helpful. I don’t remember anything being difficult about it though.
Cheers
Rob

[ashyers]

Pulled the starter and inspected the switch/pinion travel.

Looks like the starter's pinion gear was bottoming on the thrust bearing as the switch made contact. There's supposed to be a gap of 3/32"-1/8" so the contacts are,well, contacting. I pulled the switch off, cleaned it and checked it with a multimeter. There was no resistance as long as it achieved the necessary travel. I didn't have the guts to crack it open and it didn't seem necessary at this point. I adjusted the travel of the contacts and once things were back together it worked fine, except for the fuel leak !!!! The double flare going to the carb developed a hairline crack on the seam. I'll be dealing with that tomorrow. Glad I noticed the leak, which must have just started. A drip on the manifold and we'd have a different kind of Memorial Day BBQ.

I'm still interested if anyone has info on the guts of that switch.

Andy

[RCrombie]

Hi Ashyers,

Good thing you found that leak!

Here are the pictures from my parts manual. Looks like there are two types of switches that are different in how they mount to the starter. To my eye they appear to have a few differences with regards to the internals, but they operate the same. I think the later style has more insulation around the switch contacts, for one.


Cheers,
Rob

[ashyers]

Rob,
Thanks! The upper switch is the "late" switch and the one on my starter. I wonder if parts 11, 12, and 16 are available anywhere...

I chose not to pull it apart since I'd likely destroy the gasket, 9.

I'm curious about part 20. It's just a plug from what I can tell. Wonder if flushing the switch through there with some good contact cleaner would be beneficial?

Either way, need to sort out the fuel line today.

Andy