10R80 CDF Drum Sealing Ring Resizer Tool Set 2-Piece

Two-piece resizing set for the CDF drum in the Ford 10R80 ten-speed automatic. One piece is the expander that stretches a solid Teflon sealing ring enough to walk it over the drum and down into its groove, the other is the compression resizer that squeezes the ring back to bore diameter once it is seated.

Solid rings on the 10R80 do not have a cut end, so they have to be stretched on and shrunk back down. Skip the resizing step and the ring stands proud of the groove: the drum either will not start into its bore, or it goes in and shaves a spiral of Teflon off the ring that ends up in the valve body. That shows up later as a soft or slipping shift and a rebuild that has to come back apart. The compression tool has open gaps in the body so you can look in and confirm the ring is flat in its groove all the way around before the drum goes back in the case.

Install from the furthest ring position toward the outside of the drum so each tool pass clears the rings already seated. This set covers the CDF drum only; input shaft and other 10R80 ring locations use their own size tools. Fits 2017 and later Ford 10R80 applications including F-150, Mustang, Expedition, Ranger and Explorer.