reverse light switch, high resistance and leaks, why? Options

[davesprinkle]

OK, I'm now on my third reverse switch, with a consistent problem:

After a few hundred miles, the switch contacts become high-resistance (50 Ohms or so) and the switch leaks tranny fluid, filling up the wiring boot. By the way, the last two switches were brand-new Porsche replacements. I'm running Swepco 201, by the way. Anybody have any suggestions about what might be going on?

[ejm]

Vent is oposite side of the case top just before the bell housing transition.

If you remove it make note of where the vent hole is and return it to the same position or you will have a leak.

Pulled the switch and pin out of a box at the shop today. This pin had a bit of wear on the inner end, a new pin may be a few thou's longer.

[astronomerdave]

Pulled the switch and pin out of a box at the shop today. This pin had a bit of wear on the inner end, a new pin may be a few thou's longer.

Can the pin be removed from the outside of the transmission without taking the tranny apart?

So, I definitely also have a bad switch (when removed I can fully press in the switch with a punch and it never makes contact) but I don't know about my pin. Does anyone know the position of the pin should be relative to the outside of the transmission?

With the switch removed and the transmission in Reverse, the end of the pin is about 3 mm inside, measured from the outside edge of the threaded hole (in other words, from the face where the crush washer would seat to the tip of the pin is 3mm inside).

When in any other gear the pin is about 5.3 mm inside.

See photo:



Based on measurements of my existing (bad) switch, my switch would be pressed in about 1.5 mm. Presumably this is enough to activate the switch. Maybe someone knows these numbers.



Sent PM to Dr Evil to buy one of your switches.

tnx,
Dave

[astronomerdave]

(IMG:style_emoticons/default/icon_bump.gif)

Does anyone know the position of the pin should be relative to the outside of the transmission?

I wanted to try this question again because I got a new switch and pin from Dr. Evil (tnx, btw!) -- I'm using the new pin even though it is only about 0.5 mm longer than my previous pin. But when in reverse it does not push out enough to activate the switch. If I don't use the washer around the switch then the pin will activate it.

I didn't do anything to this transmission. It was working, then I removed the motor/tranny from the car, removed the motor from the tranny, installed a new motor, then replaced the new motor/tranny assembly back in the car. That's it. First thing discovered was the reverse light switch failed and now the pin doesn't seem to be coming out enough. (IMG:style_emoticons/default/sad.gif)

Did something happen suddenly? How much should the pin move from a fwd gear to reverse, and where relative to the edge of the hole? What could have happened?