I promised to show you guys this stuff. These are actually one of the best converters ford has built for a car application in years. The only converter nearing this stall was the 10 inch c4 units in the mustangII's
These converters are 10.5 inches in diameter and have a k-factor of 165
giving them a stock stall ratio of about 2800 rpms.
Ford really did everything they could to make this a reliable unit. Under the power of the stock engines they hold up well.
The pump comes from the factory furnace brazed.
All models used the same pump. The explorers used a different stator as well as a few other applications. The mustangs and ls cars had the high stall stator.
The turbine also is furnace brazed from the factory.
The cases were made a of a heavy gauge material so ballooning isn't much of an issue. The major problems are the amount of clutch surface, material of the friction and the splines that hold this multiplate unit together. In the only complete failure I have seen the splines in the front cover completely stripped out. Here is the stock cover.
Here is the friction disc that was used from the factory. It is double sided, both frictions are equal measuring 8.9 ID to 9 inch OD
This gives each friction 14.6 square inches of friction making a total of 29.2 square inches of friction in the stock unit. You then have to calculate the loss by grooves in the factory frictions which takes away about 1/3 of the area.
The major issues people find are with the retaining plate for the friction.
The tabs on that plate will get weak over time and rattle terribly.
I prefer to use a billet piston which eliminates all of those and converts to a single plate for all applications over about 300 rwhp, also in explorers which are so heavy. The billet piston...
this pistons dimensions are 7inch ID by 9.5 od giving it a surface area of 32.38 square inches of friction. A slight improvement but a weak link removed. Also about 1 lb lighter.
The next picture contains the billet piston installed on the turbine as well as the stock stator. The stock stator was made well , it has a nice roller clutch capable of anything this trans can handle and has a thrust bearing on the load side.
There aren't many other modificatiosn needed to this converter, pitching the fins will increase stall by about 400-500 rpms. Honestly I don't think this transmission will handle much more multiplication than this anyway. The input shaft is only 5/8 and the overdrive planet makes the shaft look strong in comparison. The first time I ever looked inside one of these transmissions I had to be amazed that such thin wimpy parts actually ever worked at all. Everyone wants to add friction to the trans and make it shift harder, I suggest making it have controlled slippage via the tune and use the oem frictions they were very good frictions.
Alan
These converters are 10.5 inches in diameter and have a k-factor of 165
giving them a stock stall ratio of about 2800 rpms.
Ford really did everything they could to make this a reliable unit. Under the power of the stock engines they hold up well.
The pump comes from the factory furnace brazed.
All models used the same pump. The explorers used a different stator as well as a few other applications. The mustangs and ls cars had the high stall stator.
The turbine also is furnace brazed from the factory.
The cases were made a of a heavy gauge material so ballooning isn't much of an issue. The major problems are the amount of clutch surface, material of the friction and the splines that hold this multiplate unit together. In the only complete failure I have seen the splines in the front cover completely stripped out. Here is the stock cover.
Here is the friction disc that was used from the factory. It is double sided, both frictions are equal measuring 8.9 ID to 9 inch OD
This gives each friction 14.6 square inches of friction making a total of 29.2 square inches of friction in the stock unit. You then have to calculate the loss by grooves in the factory frictions which takes away about 1/3 of the area.
The major issues people find are with the retaining plate for the friction.
The tabs on that plate will get weak over time and rattle terribly.
I prefer to use a billet piston which eliminates all of those and converts to a single plate for all applications over about 300 rwhp, also in explorers which are so heavy. The billet piston...
this pistons dimensions are 7inch ID by 9.5 od giving it a surface area of 32.38 square inches of friction. A slight improvement but a weak link removed. Also about 1 lb lighter.
The next picture contains the billet piston installed on the turbine as well as the stock stator. The stock stator was made well , it has a nice roller clutch capable of anything this trans can handle and has a thrust bearing on the load side.
There aren't many other modificatiosn needed to this converter, pitching the fins will increase stall by about 400-500 rpms. Honestly I don't think this transmission will handle much more multiplication than this anyway. The input shaft is only 5/8 and the overdrive planet makes the shaft look strong in comparison. The first time I ever looked inside one of these transmissions I had to be amazed that such thin wimpy parts actually ever worked at all. Everyone wants to add friction to the trans and make it shift harder, I suggest making it have controlled slippage via the tune and use the oem frictions they were very good frictions.
Alan
