Backup light switch for transmission?

[W_A_Watson_II]

That looks like the one I used to fix the Jeep t18 switch that was discontinued.

[maineSS]

That's an interesting adapter- did you have to drive it out with a drift? The switch I got isn't a ground-type- the switch is insulated from the case and the ball, and only passes current thru the terminals.

[W_A_Watson_II]

I wasn't an adapter, it's whats left of the old (discontinued) switch. I was able to remove it by wrenching it back and forth and it loosened up and out. I adapted it by adding a nut I shaved to allow the old switch plunger to activate the new switch.

[maineSS]

So the original was friction fit? Don't see any exterior threads on the switch body...

[W_A_Watson_II]

So the original was friction fit? Don't see any exterior threads on the switch body...

Yep, that is how it was installed, no threads on either part, and the switch no longer available for purchase. The Jeep and Ford T18 had different case tops and the switched mounted 90**° to each other. The Jeep switch had a mot of motion in it apparently to account for the fit variations.

[Tom Petroff]

Maine SS,
Saw this today at Joe's site tought I would pass it along.
Don't know if you visit there or not.
ChrisCase made it look easy.
TGP

Switch is from 904-707 Torgueflite. $12 Combination neutral safety and back up light switch. Use the two outer prongs.

Simply knock out the end plug, thread hole for 3/4x16 thread, the bore for the rod within is the right tap drill size already! Screw switch in. It didn't even need adjustment.

Next trip to the junk yard I'll pick up a couple pig tails. Unless somebody knows a source and number for aftermarket?

I think the crash box would be the same, but I haven't tried it yet.

****, I was hoping to make a fortune machining adapters to do the job. Another get rich quick scheme down the drain.

[maineSS]

Tom-

I assume this switch is like the dome light in operation -normally open, held "off" by the shift rod until you shift into reverse and the rod moves forward?

[Tom Petroff]

Can't answer that.
Been to long since I was in the top rails to remember which way they move.
Thought it was interesting though.
TGP

[maineSS]

Torqueflite Switch

I went down to Napa and bought PN #NS 6562 for $15, the 1963-1990 Torqueflite Backup/NSS switch to see how it works.

Pic #1 shows the side view of the switch and gasket (black ring). The length of the threads is 1/2", the plastic boss is 5/32", and the pin is 1/16", for a total of 23/32".

The pastic boss is collapsible along with the pin (pics #2 & #3). This allows you some room (5/32" max) when screwing the unit into the tranny- the rail can still move back a bit if it totally collapses the pin and needs more travel.

The two outer prongs activate the backup lights, and the pin has to collapse ~ 1/32" to turn "off". Collapsing the boss without collapsing the pin won't turn the switch off. There's no continuity between either of the prongs and switch casing, or between the center prong and the casing or either pin. The center prong has continuity to the pin whether the plastic boss is collapsed or not. It looks like the center prong is ground for the NSS in the Torqueflite.

The shift rail would have to keep the pin depressed to keep the switch "off" for the backup light circuit, just like Matt's Dome Light switch mod. The center pin could be used as an interruptible ground for some other function. The only question here is how deep the rail sits back from the plug in the early crashbox- Matt was seeing ~ 1/2" in his M37.

I went to Chris Case's thread on this mod at dodgepowerwagon.com, and found it interesting he was looking at dome light switches when an old parts man pulled this switch out and told him to try it. His PN's were 5290 BWD brand and NS II SMP brand. It does look like a real good possiblity....

[Matthew Ziegler]

looks good

Looks like a really nice setup, just be careful, my original design was a plunger activated microswitch nice little bracket using the two rear top cover bolts and a 3/4 od 5/16 id seal...It worked great untill I crushed it trying to install the tranny cover.there's not a lot of clearence at least in the m37 between the tranny cover and where you have to put the switch, pw's may be different. so do the switch or mock one up using something similar lay the cover in place and look under the truck, you can see it from below.

[maineSS]

There may be height differences between the early and late style crashbox tranny, as well as the syncro tranny. Owners of each type will have to measure before proceding to the threading stage for the Torqueflite switch. However, Matt's Dome light mod may very well fit fit trannys where space is tight- experiment and report back, one way or another we'll have backup lights for all!

[Matthew Ziegler]

24 volt lights

Check your local caterpillar or heavy equipment dealer for lights, I used Trico equipment in Totowa new jersey, they have both 12 and 24 volt models in a variety of shapes sizes and prices. a good no drill mounting bracket can be had in the electrical aisle at Home Depot, they are called beam clamps, small cast c clamp looking affair for anchoring pipe and conduit to steel I beams. they come with several drilled and tapped holes. the ones I purchased were tapped to 5/16-18 also work well as exhaust hangers. The best part is you don't have to drill any holes in the chassis.

[maineSS]

Matt-

Which rail does 4th gear use? I'd like to do another switch for the Dennan OD so it will only activate in 4th.

[Matthew Ziegler]

4th gear

should be immeadiately to the right of the one used for the backup lights, however third is in front of it so it moves two ways, may take some careful adjusting or not work. I helped a friend of mine restore a 55 willys wagon with a warn overdrive in it, since he didn't want an extra shifter poking out of the floor we activated it with a bimba cylinder, they are pneumatic. This was powered up with an underhood air horn compressor and he replaced the gearshift knob with one that had a pneumatic valve in it from a garbage truck. The nice thing about this is he was able to split every gear, first, first high, second, second high and so on, even reverse. he simply held the clutch down and flipped the knob to shift, more options on hills, in traffic etc. so, why limit yourself to fourth when you can reap a real benefit from this gizmo? any truck stop or heavy equipment dealer will have a switch with a bracket or a knob with a built in button or switch. With a little practice you'll have 8 forward gears in high range and two reverses, pretty cool.

[maineSS]

The Laycock OD used in the Dennan setup wasn't rated for tons of torque, although it can be built up some. They were generally rated for ~140 Hp when used with Volvos, and whatever torque the Vovo engine put out. The Dennan is the "J" type, the "P" type used in turbo Volvos can handle more, and is the basis for the Gear Vendors OD. If you want the cone clutch to last, don't run lots of torque thru them. You don't have a direct shift linkage like the Warn, so it's slower, which kind of limits it's use as a gear splitter.

I assume 4th would be the farthest position back on the 2nd rail's travel?