Trick, functional jake brake grenade shifter

[Another Ahab]

I finished the wiring from the firewall to the jake heads today! I made some 10 ga. standoff brackets

Nice

 

[US6x4]

The wye connector handles the LO setting (front & rear heads) so one wire loops back around and joins up with one of the HI wires and same with the front head. I'm really impressed how the male rubber cover worked out! Looks very clean and pretty close to what factory wiring could've looked like.







And that's it for the install - next up is the scary part; add power to it and see if any magic smoke escapes and see if the circuits work the way they should...

 

[Another Ahab]

And that's it for the install - next up is the scary part; add power to it and see if any magic smoke escapes and see if the circuits work the way they should...

 

[US6x4]

I turned on the power (12V) and I took the test light to each power junction in sequence to make sure each leg of the circuit was sound before I let the voltage flow to the next point: battery ‐>relay->clutch switch->throttle switch->rotary switch->LO circuit->HI circuit. No smoke escaped and the center jake head remained isolated with the switch on LO. The LO & HI circuits still function as I wanted even though I forgot to put diodes on the LO side. And looking closer at it I actually only needed the diodes on the 2 HI side heads that would prevent the voltage from the LO side from back feeding and traveling down the 2 HI side wires and into the 3rd HI side wire (center head). My circuit ended up looking like this:


I took it for a road test yesterday and electrically, everything works like it should!

 

[US6x4]

I decided to make another grenade shifter for some lucky person. After getting a little stir crazy this winter and looking at my jigs and extra parts I figured it was time so I ordered up an NOS shifter and got to work.












The shifter base off of this new shifter was different than my first one; it was hardened like crazy. The heat treatment is super cool but a drill bit wouldn't drill it and a tap wouldn't tap it. We had to use a 5/16" carbide end mill to put a centered alignment hole in it!

 

[US6x4]

The stick always takes the most work.













The mockup looks good and clears all the levers

 

[US6x4]

This time the adapter bushing between the stick and the grenade is made of aluminum instead of brass as it's 1/3 of the weight.

I was finally able to get this new shifter and my original M813 shifter on a scale for comparison. The complete grenade shifter is 10 oz heavier.

When mocking up the new shifter I noticed it was the new spring and new base socket that made it feel like a new transmission (and not the top hat or shift forks). It was really crisp and tight and the new spring helps keep the shifter in its place rather than flop around.

I'm a bit jealous that my first grenade shifter is not that tight.