Expands the Teflon sealing rings onto 10R140 drums and shafts, then resizes them back down so the units slide into their bores without shaving a ring.
If you have a Ford 10R140 ten-speed on the bench out of a 2020-up F-250, F-350, F-450 or larger Super Duty and you are about to fit new Teflon sealing rings to its shafts and drums, this kit is for that step. It is a five-piece expander and resizer set for the 10R140: two tapered expander cones that walk a new ring up and into its groove, and three sleeves that squeeze the ring back down afterward so the part slides into its mating bore. As pictured, the pieces are molded from a blue polymer, not metal, which keeps them from scratching ring lands and bores.
The 10R140 feeds its clutches through rotating shafts and drums, and the oil passes from one part to the next across Teflon sealing rings. A new ring is a closed or tightly fitting hoop that is smaller than the land it has to climb over. Stretched by hand or over a screwdriver it tears, kinks or takes a permanent oversize set. Rebuilders working on Ford ten-speeds report that rings expanded too far never close back down and never seal, even after the unit is assembled. The answer is controlled expansion on a smooth cone, then a sizing sleeve that brings the ring back to bore diameter before assembly. Skip that and the shaft either will not enter its bore, or it goes in and shaves the ring.
If your rebuild kit includes new Teflon sealing rings for the shafts and drums, and most full 10R140 overhaul kits do, you need a way to install and size them. Hold the new ring next to its groove. If it will not pass over the land without stretching, a cone is the safe way to get it there. After installation, if the shaft binds when you try it in its bore, the ring needs resizing. Air-check each clutch circuit after assembly with regulated shop air: a clean apply and hold means the rings sealed.
This set is built for the Ford 10R140 ten-speed used in 2020 and newer F-Series Super Duty trucks, behind the 6.7L Power Stroke diesel and the 7.3L gas V8. The listing does not publish individual sleeve diameters, so test-fit each piece against your shaft or drum before you start, and make sure the cone tip passes the ring groove without catching. If you are working on a different Ford or GM ten-speed, compare your ring diameters before relying on this kit; for that, send us your transmission and we will tell you what we know.
While the transmission is out, it is a good time to fit a 10R140 filter and pan gasket kit or the DF-440 filter kit for the 6.7L diesel. Owners chasing erratic shifts as well as a rebuild often replace the 10R140 eight-piece solenoid pack, and a cast aluminum deep pan adds fluid capacity for towing.
| Fitment | |
| Type | |
| Function | |
| Use |
It is made for the Ford 10R140 ten-speed in 2020 and newer F-250 through F-600 Super Duty trucks with the 6.7L Power Stroke or the 7.3L gas V8.
Five pieces as pictured: two tapered expander cones and three sizing sleeves, molded from blue polymer.
Teflon rings stretched by hand or over sharp tools tear or stay oversized, and an oversized ring will not seal or will shave when the shaft enters its bore. A cone expands it evenly and the sleeve sizes it back down.
Until the ring has closed down flush with the shaft surface, usually several minutes. Assemble soon after so it does not relax back out.
The kit is sized for the 10R140, and the 10R80 is a different transmission whose ring diameters may not match. Compare the sleeve and cone diameters with your parts before using it on another transmission.
