I deviate from the firewall to rebuild the A/C Box. What a dirty mess this thing is.
Armed only with this exploded view from the shop manual, I get to work.
I remove the (13) 1/4 inch screws that hold the Evaporator and Blower Upper Case Cover on.
I also remove the (2) 7mm A/C Blower Relay screws.
I remove the 7mm screw that holds the Evap Tube.
With that screw removed, I can move the Evap Tube bracket clock-wise to clear the top cover removal.
I remove the 10mm bolt that holds the A/C Compressor Control Relay bracket and Accumulator.
Here it is with the top cover removed.
The A/C Evaporator just pulls right out.
There's a 5/16 screw that holds the Heater Core Clamp and Ground Strap.
I get the clamp out of the way...
...and pull the Heater Core.
I begin removing the 1/4 screws that hold the multi part case together.
Two here.
Inside the box I remove the Blower Case screws. One on the floor of the box.
One at the top back of the case.
One on the outside of the box near the Air Inlet Valve Door.
With those 1/4 inch screws removed, I cannow pull the Blower Case.
I remove the screws that hold the Hot/Cold Door in place. One at this baffle plate.
One on the other side of the Hot/Cold Door housing.
I mark where the blend door rod snapped into the arm for reference.
Splitting the case apart makes getting the blend door out easier, so I start removing the 1/4 inch screws that hold the last pieces together.
Two more at the bottom of the case.
Now I can split the front and back halves of the case apart.
With the case split apart, the blend door just comes right out.
This clip presses into the bottom of the Blend Door Housing. This is where the bottom of the Heater Core pushes into to hold it.
Finally, I have the A/C Box broken down into 6 pieces. Now I just have to clean this mess.
I move on to restoring the dingy and rather ugly looking firewall.
After years of neglect, it's going to take some work to get this back in shape.
The A/C box looks like 10 pounds of chewed bubble gum. What a dirty mess.
I've been gathering parts over time, to include a new Brake Booster, Heater Core, Evaporator, Blower Motor, A/C Box Seal Kit, and various gaskets.
So you know how these things go, one project leads to another. I end up going all out with this. Notice how the Brake Booster gasket was installed upside down from the factory.
So the Booster and Wiper Motor get pulled....
Then why not pull the Steering Column....
A/C Box comes out easier with no dash... Right??
The A/C Box as a complete unit on the floor.
Finally, the Firewall all stripped down and ready for some well needed TLC. (But maybe that A/C Box needs it first hmmm)
I tackle an annoying sheet metal issue. The striker bolt on the drivers door frame has the metal where it mounts cracked almost 360 degrees around.
This cracking comes from years of the door locking mechanism smacking into the striker bolt. This was due to worn out hinge bushings that never got fixed.
I break out the metal glue gun. This is the Hobart Handler 140. It's a nice DIY welder that you can plug into a normal outlet and get to burnin. I used this on the 9" rear.
I bent up a U-bracket to pull the metal out flush to get some tack welds on to hold it in place.
With some tack welds around the whole perimeter, I can get to doing some stitch welding to finish it up.
I start at the 12 o'clock position and go 12, 3, 6, 9 all the way around. I hit it with an air nozzle to cool it down and repeat. I keep going in between existing welds until it's solid the whole way around.
I use the edge of a grinding disk to knock down the weld and then a flap disk to smooth it out.
I feel better now. That stupid circular crack was mocking me every time I walked by the 442. Not any more.
I bought a set of G-Body Door Striker Plates (similar to the ones pictured here). They're supposed to strengthen the area around the striker by distributing the load to a wider area.
I got my TH400 back from the Trans Shop. It's been warmed over with an ATI Reverse Manual Valve Body, 34 Element Sprag, 4th Friction added to the Intermediate Clutch Pack, and the Thrust Washers replaced with Roller Bearings.
Here's where the Speedo Gear Housing bolts into the trans case.
First I remove the (6) 9/16 bolts that hold the tail shaft housing on and set the tail housing to the side.
I rotate the Output Shaft until the machined hole for the retention clip is facing up.
I lay out the parts for the speedo gears. The "Drive" gear is 15 tooth, and the "Driven" gear is 39 tooth. This number was arrived at by using an online calculator to input gear ratio, tire height, and drive gear numbers.
This is the "Drive" gear retention clip. The raised portion fits into the machined hole in the output shaft.
Here's a pic of the retention clip sitting on the output shaft and positioned on the machined hole.
The "Drive" gear has a notch that will need to be lined up with the retention clip.
I slide the "Drive" gear on the output shaft and position the gear notch in line with the retention clip. There is a "pig tail" on the clip that must be pushed down so the gear can slide over the clip.
The "Drive" gear installed with the retention clip "pig tail" locking the gear in place. On to the "Driven" gear and Housing.
Here's the housing with the "Driven" gear installed. I lubed the shaft with trans fluid to protect the o-rings. This housing covers gears 34-39. There is a different housing for gears 40-45.
With both pieces together, I lube the outer housing o-ring and install. I lube the gears with trans fluid as well.
Here is the housing installed. I make sure the two retainer clip pads are facing the case bolt hole.
Since the tail shaft housing is off, it makes it easy to check correct gear engagement. If this were in the car, I would just go by feel when installing to make sure the gears meshed correctly.
Now I just place the housing retainer clip into the cast slots of the speedo housing and tighten the bolt.
