Brake Shift Interlock Mechanism

ShimShim

ShimShim

Well-Known Member
Joined
Apr 21, 2005
Location
Charlotte, NC
The saga of my Jeep continues. Got everything put back together and took it for a test drive today. I'm happy to report that everything I worked on seems to be holding together and none of my duct tape or zip ties have let go yet.

I did find a new problem that I am going to assume is coincidental, but who knows. I noticed after pumping the brakes on startup to get the pads to engage, that there was a clicking at the gearshift (automatic trans) that I've never heard before. It only clicks when I'm in Park and I press the brake and release it. I then noticed that I can shift out of park even if I am not pressing on the brake pedal.

I know there is a brake shift lock mechanism. And it seems to have gone bad. Or at least is malfunctioning. But my searching for a solenoid (which I assume it uses) is coming up empty. Plenty of cars have a brake shift lock solenoid. But I'm not finding one for a JKU.

So, experts of the Jeep world, what mechanism does my JKU use to prevent shifting out of park unless the brake is depressed? I'll likely tear into it tomorrow and see what I can see. But if I need to order parts, I need to know what that part is called and my google fu is failing me.
 
There should be a cable there solely for shift interlock. It will be the smaller of the 2. Make sure it is hooked up. There is adjustment on it if need be.
If the solennoid is failed, you'll need a replacement shifter assembly.
 
Jody Treadway said:
There should be a cable there solely for shift interlock. It will be the smaller of the 2. Make sure it is hooked up. There is adjustment on it if need be.
If the solennoid is failed, you'll need a replacement shifter assembly.
Click to expand...
That sounds expensive. Here's hoping I can adjust it back to working.
Any ideas why it could have spontaneously stopped working? I did a lot of brake work, but nothing inside the jeep, just at the wheels and the parking brakes.

For additional info, I cannot shift if the key is off. But nothing is stopping it if the Jeep is running and not pressing the brake. Is there a different mechanism that keeps it from being shifted with the key off?
 
ShimShim said:
That sounds expensive. Here's hoping I can adjust it back to working.
Any ideas why it could have spontaneously stopped working? I did a lot of brake work, but nothing inside the jeep, just at the wheels and the parking brakes.

For additional info, I cannot shift if the key is off. But nothing is stopping it if the Jeep is running and not pressing the brake. Is there a different mechanism that keeps it from being shifted with the key off?
Click to expand...
The solenoid is energized with key on or running and when the brake is applied. I'd see if you can adjust the cable to get it working properly. You'll need to remove the console enough to access under the shifter.
 
Jody Treadway said:
The solenoid is energized with key on or running and when the brake is applied. I'd see if you can adjust the cable to get it working properly. You'll need to remove the console enough to access under the shifter.
Click to expand...
Thanks for the help. You always come in with great advice. Any ideas on the clicking I'm hearing that I'm sure wasn't there before. Clicks on when I press the brake, off again when I let off the brake. Does that make sense? It sounds different pressing or releasing.
 
ShimShim said:
Thanks for the help. You always come in with great advice. Any ideas on the clicking I'm hearing that I'm sure wasn't there before. Clicks on when I press the brake, off again when I let off the brake. Does that make sense? It sounds different pressing or releasing.
Click to expand...
There will be an audible click as the solenoid energizes and moves. Maybe something came loose and your hearing noise due to excessive movement?
Pop off the console and take a gander.
 
Jody Treadway said:
There will be an audible click as the solenoid energizes and moves. Maybe something came loose and your hearing noise due to excessive movement?
Pop off the console and take a gander.
Click to expand...
So I took it apart. With the console/trim removed, everything worked as it should. Had to press brake to shift. Put it back on and it shifted without pressing the brake again.
Got to looking closely and found the manual override out of place...

IMG_1326 copy.jpg


When the console was in place, it pressed down on the mechanism and released it, allowing the shift without the brake depressed.

IMG_1327 copy.jpg


Popped it back in place and put everything back together and it works as intended. How this happened in the first place, I have no idea. Didn't mess with that area at all. But I'm just happy this was a free fix.

There's still an audible click as I release the brake pedal that I swear I never heard before, but I'll just chalk that up to never noticing it. Now that everything is back in place, it sounds different that what I was hearing which serves to confirm to me that it was just the manual override out of place.

Thanks again @Jody Treadway
 
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