[Coyote X]

Here is what I have put together as a towing upgrade for my 94 astro.

4L60E transmission valve body separator plate 1993-94.
4L60E-HD2 Performance reprogramming kit™ 1993-03, .500 boost valve included.
700R4 4L60E Corvette, 2nd gear servo piston with o rings & sealing rings
700R4 4L60E transmission, Sonnax super hold 4th gear servo piston
4L60E Transmission, ATSG transmission manual 1992-on
Air Lift 59504 Ride Control Air Springs, Rear Kit, For Select GM Vans
Air Lift 25592 Load Controller II W/Lps
2X hayden 10,000lb transmission coolers.

I already have an old Kelsey-Hayes hydraulic actuated brake controller from my jeep. I have taken the hydraulic piston out of it and modified it so a cable operates it. I can attach the cable to the brake pedal and it will actuate the trailer brakes in proportion to the brake pedal being pushed. It is also adjustable so I can vary the trailer braking amount.

So other than the .500 boost valve that I think is a bit big I will be installing all this stuff as soon as it is delivered hopefully this weekend.

I have already towed a broke down escort wagon and a ford ranger with just the trans coolers installed and despite having to be slow because the brake controller isn't connected yet it pulls fine as it is. I just want to make sure it lasts a really long time and is reliable. My biggest normal load other than helping neighbors out randomly is to take a Camaro to the drag strip 75 miles away and occasionally hauling a Kubota BX-24 tractor around.

So does anyone see anything that I am missing? I would rather not take the trans out and rebuild it so anything that doesn't involve removing it would be ideal.

 

[gtkane]

I think you have it covered, as far as bolt-on is concerned.
Inside the trans, it is a good idea to install the upgraded reaction sun shell, and forward sprag,as they are a known weak point.
Also, consider a newer model digital brake controller(like a Voyager), as opposed to a cable or hydraulically operated unit. They are cheap.

 

[Coyote X]

I have the trans coolers installed and the air bags. I will probably hold off until warm weather before getting into the trans and doing the transgo kit. I did pick up the parts to add a T fitting and the assorted hardware to connect to the trans fluid cooler output line right at the transmission and will put a stock water temp sender there. I will put a switch on the dash so I can switch the coolant temp gauge between the water temperature and the trans temp. For the most part I don't need to know the trans temp but I can this way look at it any time I need without having to add another gauge to the dashboard. Keeps it nice and clean looking this way.

As far as the brake controller I have built a much better solution than anything on the market right now. I have a slide potentiometer to mount to the underside of the dash. I can use a small rod to connect it to the brake pedal. This lets me know exactly how much I am pushing the pedal. I have an arduino board programmed to read that pot and another mounted to the dash for a sensitivity adjustment and it outputs a PWM signal (35A capable) to the trailer brakes and lights up a 6 segment sequential led display to let me know how much brake pressure the trailer is getting. The whole setup costs around $20 to build and looks like it will have better control than anything else available.

One of the blank dashboard panels beside the power mirror controls is able to hold all this extra stuff and will look nice. It will have the led brake strength indicator, toggle switch for the temperature gauge, knob for the brake sensitivity, and another led for the torque coverter lockup. If I can find the right knob for it the whole thing can look almost stock.

Once I get the brake controller tested and I am sure it works good I will post the schematic and source code for anyone to be able to build their own. It is a pretty simple circuit to build so anyone who can solder should be able to build it easily.

 

[Big_kid]

Sounds pretty nice, thanks for sharing. I'll look forward to seeing your writeup!