1956 F100 (Project Fat Max) Build Thread

[Dr G]

This is a follow up to the discussion above regarding the amount of ground clearance I had relative to my deep sump B&M transmission pan.

I decided I was not comfortable with it, and that I had to improve the situation. My first solution was to see if I could find a 2WD AODE pan. I assume this would match the available 2WD filter, and should provide more ground clearance than the common 4WD pan.

I found a pan on an auction site that was advertised as AOD/AODE/4R70W, and it looked like a flat bottomed pan that I wanted. I went ahead and purchased it, cleaned it up, flattened it out. Then when I compared it to an AODE gasket I discovered it would not work. Not only did the holes in the pan not match the gasket. But the gasket rail of this pressed steel pan did not even match the 'shape' of the AODE gasket in one corner. See pic below, upper left-hand corner:



I can only assume that this pan I bought is specific to the AOD transmission only and will not fit an AODE nor a 4R70W. So I decided to make my own pan to my own specs.

Here is a picture of the AODE transmission pan I fabricated:





My goal for building this pan was to achieve decent fluid capacity with maximum ground clearance. And to have a pan that would survive if it did accidentally get hit by something (a speed bump etc.)

I built the pan rail and bottom side from 3/16" mild steel. I cut out the inside portion using a plasma cutter and used it for the bottom of the pan. The sides of the pan are 1/8" steel. I clamped the pan rail to a big 2" thick piece of surplus aluminum I have, to keep it flat during tacking together the pieces of the pan. When the pan was complete I leak tested it with water. I did find 3 pin holes I had to fix. Lastly I took it to an engine machining shop where the run the gasket rail on a large belt sander to make sure it was truly flat. They hardly removed any material at all, the rail was pretty flat to begin with, meaning my technique worked as planned. The only issue with this custom pan is that it is quite heavy at 14 lbs. If I did it over I would use somewhat thinner steel plate.

Here are some pan capacity measurements I took:



My custom pan capacity (5.75 qts) is not far off of the 'standard' AODE/4R70W 4WD pan that most folks would use (6.25 qts). However, I will lose almost 3 qts capacity in relation to the aluminum B&M pan that I have been using (8.50 qts). To make up for this I have built a custom 3 qt aluminum tank which will be inserted into one of the lines running back to the trans cooler. Thus the total volume of fluid flowing through the system will be the same. More to come on this.

Here is the new custom pan next to the B&M deep sump pan:





And here is a shot of the bottom side of my truck with just the 2WD AODE/4R70W filter installed. As I see it this determines the limit to how much ground clearance you could expect to gain with any type of pan. You still have to fit this filter. And some of the solenoids hang just about as low so even running without this filter would not gain one very much clearance.