Passing Gear Switch 68 with TH400
Instructor
Joined: Jul 2001
Posts: 168
Likes: 4
From: central Washington state
Re: Passing Gear Switch 68 with TH400 (LAWTON54)
Lawton;
When I bought my '73, the switch worked intermittently, i.e. once in a while. I didn't even bother looking for a new one, I just took the old one out and took it apart and cleaned it up and it worked like a champ. There's really very little that can go wrong with the switch, other than a buildup of crud that eventually blocks metal-to-metal contact. The switch is not supposed to be a serviceable item, but if you're just a bit careful it can easily be taken apart. It's clear to see, then, what the problem is. And, if by chance the switch is actually damaged - contacts worn through or actuating arm broken, etc. - you can get a used switch from any Corvette wrecking yard for a few bucks. If you can't find any in your area, e-mail me and I'll give you the number for a dealer in western Washington that can help you.
When I bought my '73, the switch worked intermittently, i.e. once in a while. I didn't even bother looking for a new one, I just took the old one out and took it apart and cleaned it up and it worked like a champ. There's really very little that can go wrong with the switch, other than a buildup of crud that eventually blocks metal-to-metal contact. The switch is not supposed to be a serviceable item, but if you're just a bit careful it can easily be taken apart. It's clear to see, then, what the problem is. And, if by chance the switch is actually damaged - contacts worn through or actuating arm broken, etc. - you can get a used switch from any Corvette wrecking yard for a few bucks. If you can't find any in your area, e-mail me and I'll give you the number for a dealer in western Washington that can help you.
Safety Car
Joined: Jun 2001
Posts: 4,004
Likes: 2
From: Severna Park Md
Re: Passing Gear Switch 68 with TH400 (LAWTON54)
Heres a way to check the switch. First disconnect the the single wire connector where it goes into the trans. Clip one end of a testlight to ground and put the other into the harness connection. Turn the ignition key to the on posistion. Deperss the gas pedal hard to the floor. If the test light lights the pedal switch is working and the problem most likely will lie with the solenoid mounted inside the trans pan. If the test light does not light, move the test light up to the pedal switch to check for voltage there. The key must be in the run posistion for power to be at this switch. I had to wrap black electrical tape around the pin on my pedal switch to get it to activate because there was too much play in the switch. It would only activate when the pedal was pushed very very hard. By enlarging the pin with tape, the switch would connect without such a hard effort. I also needed to replace the solenoid in the trans as well.
