Need help sourcing manual trans 3rd & 4th gear switches

[roymil]

Hello,
I'm having trouble sourcing the 2 switches that live on top of the manual 4-speed trans and are part of the FIP fuel cutoff solenoid circuit.  One of mine is stuck closed and I plan to just replace both but haven't found any at my usual sources.   Hoping somebody knows where they can be found, or alternatives that are mechanically compatible.   I'm reposting a picture from another post that TylerS took a few years ago.  Appreciate any leads.    thanks!  Mark

[austinado16]

While searching, maybe you can free the stuck one up, with applications of Kroil and maybe some heat from a hair blow dryer?

[roymil]

great idea.  I didn't even think to try and spray it off in-situ.   I do have access from the top since my carpet is out so I'll try that first.  I'm not familiar with Kroil but I do have some WD-40 contact cleaner that is supposed to be good for electrical components and not leave residue.   

Still a mystery why Ive never seen those switches for sale at this late stage of my pagoda's resurrection.  I thought I had seen every part somewhere or another at one of the 6 or 7 different parts suppliers I've used.  I'm not seeing those switches at all on diagrams at the euro parts houses so might be these only existed on US models.

[austinado16]

I wish I could be of real help on locating the switches.  My '66 W111 coupe doesn't have them.

Kroil is a highly ranked penetrant.  You'll find it at places like NAPA, and maybe your local hardware store.  PB Blaster is another good quality penetrant.  WD-40 is typically very poorly ranked, as it was never designed to be a lubricant, or a penetrant.  WD stands for water dispersant, formula attempt, number 40.  It was designed to be sprayed on the wet electrical components in the military.  It's also a pretty good hand cleaner. 

If you have enough access to remove the switch(es) from the horizontal position, and stand them upright, that'll help the Kroil creep down in.  If you can wiggle the pin side-to-side, that will also help the capillary action and get the Kroil to seep in.  You may find if you let it sit for a day or 2, keep wiggling the pin, and applying small amounts of penetrant, it will free up.  Acetone mixed 50/50 with ATF also makes an outstanding penetrant.  Heat from a hair dryer can often help when a pin is stuck inside a switch, due to the varnish residue left behind when original lubricants or grease age and fail.

Last, or maybe "another" option, is to see if you can get the switch apart, even if you had to JBWeld epoxy it back closed.  If I saw a much better photo of the switch, maybe I could help with figuring out how to safely get it apart.  I've never seen one.

Do the diagrams on the niemoeller.de website show anything?

[roymil]

Just getting back to this search for the 3rd and 4th gear switches that live on top of manual transmissions.  No luck on niemoeller or anywhere else, and the switch is resisting all attempts to free up with many hits of PB blaster and the like.   I figure these must be somewhat common but I'm not having luck and not sure how I'm going to replace it anyway if I find it short of dropping the tranny since space is so tight so thats going to wait until I need to do the clutch.   When that time. comes I want to know I have the right switch in hand.   thanks, -Mark

[Leester]

Just a stab in the dark - from a distance those look a lot like the glove box light switch. Problem might be that the little plunger on the glove box switch is plastic - may not hold up under the car. There might be switches for other purposes that would also work. Maybe Porches (and other cars that used Bosch systems) of the era had something similar?  My 1970 280SL did not have the switches when I acquired it.  Good luck.  Lee

[BobH]

Lee may be correct, the picture isn't very clear but they do look like glovebox switches, see link below

https://www.ebay.com/itm/233945158774

[Leester]

After thinking about it, the glove box switch may have the wrong on-off function. When you push the pin in, the switch disengages. You may need a switch that engages when you push the pin in.   

Hopefully one of our electric gurus (which does not include me) will weigh in.  Lee

[BobH]

Seems like these switches were only fitted on cars with emission control systems, see Mr Peterssen's notes on the link below

The switches should be normally open, if you have a switch working the contacts can be tested with a continuity tester, open circuit when the plunger is normal, closing when the plunger is pushed. The glovebox may be the opposite as the plunger is pushed normally, when the lid is closed, and opens when the plunger is released.  Maybe the same manufacturer "K" made different switches for different applications, it looks like they also made the bakelite connectors, which have the same logo

https://www.sl113.org/forums/index.php?topic=35368.msg258470