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Ford Bronco Parts - Classic Vintage Early Bronco Parts

4R70W 4 speed automatic with overdrive

Tech article by admin and filed under - Automatic, Transmission

Time to trial fit some parts.
Transmission to engine went together. Now for the questionable stuff. The transmission dipstick. Neither the Mustang or the Explorer dipstick will fit on the first try. I have done some in vehicle checks before the engine came out to see what might work. I decided to go with the Explorer dipstick. It required a new bracket welded to the tube. Originally it bolted to the head, but the 351 is taller then the 302. I made a new bracket the bolted to the bellhousing bolt.

Hooked up the Exhaust. Wow! It cleared. Not by much, but it cleared. The headers clear, even the muffler side clears. Looking good. I clean up a few little things on the engine that need attention like the leaking dipstick on the side of the engine oil pan.

While I have the transfer case out I got the wild hair that I wanted lower gears. In went a set of Tera lows. I though that AA had bad instructions. The Tera’s had no instructions. I am not sure if mine got lost, or if it never had them. Any way, the D20 is an easy rebuild. There is an extra ring that I had no idea where it went. Called up Tera and found it goes under the snap ring holding the input gear on the spud shaft. The Tera kit comes with new seals. Considering the cost of a reseal kit, the Tera’s look like a good deal.

The following weekend I attempt to install the new creation. 351, 4R70W, and a Tera lowed D20. Stripped of easily damaged parts (headers, dipsticks, shifters, throttle body, etc. It drops in nicely, but it won’t line up. Everything hits. The valve covers hit the master cylinder (Ford motorsports tall, new item). Heads hit the firewall. Engine too far forward at the mounts (odd since it can’t go back because of the firewall clearance issue?). Transfer hitting the floor. After jacking the transfer into the floor real hard and finding things line up a little better, I cut out the floor just behind the tunnel. At last, clearance. As the transfer case comes up, the heads roll away from the firewall and allow the whole engine to slip back a little until the engine mounts line up. That was the trick. Either a body lift of cut a hole in the floor.

Now for the transfer case crossmember (images 1-4 above). After looking at the factory one, and trial fitting out of the vehicle, it was set aside and a custom one made. The drivers side perch was flipped over because I always have trouble with that bolt. I am making a custom part, why make it harder then you need to? Passenger side stayed because I can reach the top of that bolt and it would get in the way of the exhaust if I flipped it.

For bushings, I found some Jeep torque arm bushings in urethane. Drilled some 1″ holes in some scrap angle iron. Bolted it to the transfer case. Dug through the scrape pile and made a new crossmember. It goes under the front drive shaft. A little different then the factory over the driveshaft style. Measurements were made and the rear drive shaft was sent out to be shortened.

Next drop in the headers.
The drivers side, the one that is a pain every time I have to put it in or pull it out. It just fell into place. All the room you could ask for. The Passenger side, you know, the easy one. It would not fit. After hours of trying. Pulling engine mounts, transmission mounts, lifting, lowering, cursing, everything but pull the body. I was pissed. Chopped off #1 pipe. Got closer. After 5 minutes of wiggling, cut off #2 pipe. Then figured it out. #1 goes in loose. Set it off to the side. Then goes in the remnants of the header, also loose. Then #2 pipe goes in. 1½” tailpipe splice kit from Checker patches it back together and sheet metal screws hold it in place. I don’t like it, but it works for now. (image 5 below) A big hammer clearances the drivers side exhaust where it interferes with the new crossmember. (image 6 below)

Little parts go right in. The speedo cable has enough slop to stretch and fit. Starter goes in, etc. The rear drive shaft if fitted in the front. No way is the 2½” tube going to clear the pan. Mark where it is close and off to the drive shaft shop. As I cruise the freeway in a borrowed company car I look in my mirror to see flashing red and blues come down off the entrance ramp behind me. Damn it, I was just keeping up with traffic. Start pulling over to the right. Lose sight of cop in the mirrors, he is going for the car pool lane. Feeling lucky for a moment. Then he is behind me again, but further back. What is going on? Another swerve across the whole freeway (I-10 under the deck park tunnel in Phoenix if you know the area). This one cop is shutting down the entire freeway, and I am the last car to get by. Now I am paranoid. Is someone coming the wrong way on the freeway? Chemical spill ahead? Fatal accident? Someone forget to take their Alzheimer’s medicine and driving right for me? Full alert. Nobody behind me. Take the next exit. Life returns to normal. Get downtown and get a custom made 2″ tube front driveshaft made and make sure the balance weights are not going to be in the way, that’s what the marking on the rear shaft were for. It was also the right size so I could tell him that this is what size ends I want on it.

I now have all the hard parts in place and hooked up. Check the wiring from Baumann and the factory Expedition manual, and what I have. I get about half of it, the output shaft speed sensor and the digital range sensor. Another call to Greg at Baumann Engineering (this guy is great) and get the valve body wiring straightened out. A couple more connections for power and ground. A splice for TPS off the fuel injection. Pour in some AFT, start the engine for a moment, more ATF, start again, more ATF, start and let idle. A few more quarts and it is finally visible on the dipstick. A quick run through the gears. Reverse, engage. Drive, nothing. Reverse again, nothing. More ATF. Through the gears again. I am getting excited, it might actually work. I finally get drive and reverse. Pull it out of the shop. Check the fluid again. More ATF. I have completely lost track of how much ATF I have used.

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