Stretches and resizes the PTFE sealing rings on Ford 6R140 input shaft, turbine shaft and stator support so they seat without cutting or leaking.
Rebuilding a Ford 6R140 out of an F-250, F-350, F-450 or F-550 Super Duty and staring at a bag of solid Teflon sealing rings? Those rings are the part of the job that catches out first-time builders. They do not stretch like cast iron hook rings or rubber O-rings, and one that goes on twisted, nicked or left oversized will leak apply oil the moment the truck is back on the road. This 6-piece kit gives you two expander cones and four downsizer sleeves so each ring goes into its groove cleanly and comes back to size before the shaft goes into its bore.
The 6R140 routes clutch apply and lube oil through the input shaft, the turbine shaft and the stator support, and each of those passages is sealed by PTFE rings sitting in machined grooves. The rings rotate against their mating bore, so they must sit flush and round. The kit covers four ring locations: the input shaft, the turbine shaft, the stator and the front stator support. It is set up to do the job of the two Ford service tools for this unit, T-307653SAC (turbine and input shaft) and T-307657SAC (stator support). Push the ring over an expander cone and it opens just enough to drop into its groove without being rolled or pried. Slide the matching downsizer sleeve over the shaft and it squeezes the ring back down so it will enter the bore instead of shaving on the edge. The pieces are a non-marring polymer, so they will not scratch ring faces or shaft journals, and a fluted handle comes with the set.
A cut ring leaks apply pressure from the circuit it seals, so the problem looks like a weak clutch or a solenoid fault. Air-check each clutch circuit on the bench before the case goes back together; a hiss at the shaft instead of a firm piston apply points at a ring. GEARS magazine also notes that the 6R140 input shaft is spin-welded to the 4-5-6 drum and that weld can break, so air-check the assembled pack to catch it. If the truck is already together and engagement is slow, read our 6R140 delayed engagement guide first, and the 6R140 rebuilder's guide for the faults that mimic a ring leak.
The kit is listed for the Ford 6R140 six-speed automatic: 2011-up F-250, F-350, F-450 and F-550 Super Duty with the 6.7L Power Stroke or the 6.2L and 7.3L gas engines, 2012-up E-350 and E-450, and 2016-up F-650 and F-750 medium duty. It is not for the lighter 6R80. If you are not sure which unit you have, check the transmission ID tag or send us your year and VIN. Every 6R140 part we stock is on the 6R140 parts page.
This set is the budget choice. If you rebuild these every week, the 7-piece installer and resizer kit adds a piece, and the input assembly installation tool lifts and centers the roughly 75-pound input assembly so the rings you just sized survive the drop. Most builds use this kit alongside a full 6R140 rebuild kit, which supplies the rings themselves.
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No. It is the tool set only: two expanders, four downsizers and a handle. The rings come in a 6R140 rebuild or overhaul kit.
Solid PTFE rings barely stretch. Rolling them over the shaft by hand tends to leave them oversized, twisted or nicked, and a ring that does not sit flush will leak apply pressure.
It is set up to do the job of Ford T-307653SAC for the turbine and input shaft and T-307657SAC for the stator support.
It is listed for the 6R140 only. The 6R80 uses different shaft and ring sizes, so do not count on it fitting.
Leave it on for a few minutes so the ring takes its set, then assemble right away before the ring relaxes.
Use clean MERCON LV, the fluid Ford specifies for the 6R140, or a transmission assembly gel.
