Auto trans braking

[Zjohnsonua]

...The big draw back with any auto is lack of transmission braking.

Came across this thought in another thread. I agree. The converter slippage sucks. Then I remembered that Jacobs sells an inline exhaust brake kit that locks the converter in certain conditions to allow some real exhaust braking power for HD pickups...

Is anyone doing something similar for crawlers? So long as the trans isn't going to be shifting, nothing would get hurt.

 

[baldilocks]

Came across this thought in another thread. I agree. The converter slippage sucks. Then I remembered that Jacobs sells an inline exhaust brake kit that locks the converter in certain conditions to allow some real exhaust braking power for HD pickups...

Is anyone doing something similar for crawlers? So long as the trans isn't going to be shifting, nothing would get hurt.

I happen to have a PacBrake exhaust brake on my Dodge. The converter is commanded to unlock during shifts.... usually..... those breaks are rather expensive and they are made to fit larger diameter systems than a gasser has.

Perhaps there is a wiring wiz in our midst that could tell us how to rearrange stock wiring in order to install a manual lockup switch. But on the trail I’m sure that we’d be stalling our engines at very in opportune moments. The whole idea sounds like it’s more trouble than it’s worth.

 

[Zjohnsonua]

My rig came with one as well. Super slick and agreed they're $$$. Wasn't suggesting they be used here - totally wrong application - it got my gears going is all.

Once upon a time I did this kind of hodge-podgery for living, which is what really got me kicking the idea around. So long as the controller could see the throttle at 0%, it might be able to do its thing. I may kick this around a bit once the UZ is driving.

 

[baldilocks]

There must be a way to use the factory wording and a switch to control the TC manually.

 

[Zjohnsonua]

It can be shorted to activate. Having it automatically unlock when power is needed is where the work is.

 

[74fj40]

I’ll need to dig up a diagram.
But you can use the brake switch to trigger a relay when you release the brake pedal. This way as soon as the pedal is released the torque converter lockup is engaged. Great for rock crawlers. Not so much on the street. But you could probably put it on a switch as well.

 

[ThreeEyedBandit]

I did this on my manually shifted A442 Isuzu swapped 80. I had an old Subaru brake switch, which has an extra normally closed side for the cruise control. Wired the factory OD switch through this and onto the TC lockup solenoid. Worked super well, and was nice to have the backup of the brake switch.

 

[Zjohnsonua]

I knew this wasn't a new idea. I'm surprised its not out there commercially for all the 80s to grab as a kit.

 

[baldilocks]

I’m thinking I’d prefer to have a simple switch that I could flip on and off with a finger for down hill terrain. And I’m not sure that would be a good idea due to the lowest available gearing there is for an 80, acceleration not deceleration might be the result of locking the TC in an off road scenario where we want to creep.