Expands and then resizes the Teflon sealing rings on Ford 6R140 shafts and drums so they slide into the bore without twisting or shaving.
A soft apply, a slipping gear or a no-move complaint a week after a Ford 6R140 rebuild very often comes back to one cheap part: a Teflon sealing ring that was pinched or shaved on the way into its bore. This expander and resizer set is made for the 6R140 TorqShift six-speed in 2011-up F-250, F-350, F-450 and F-550 Super Duty trucks with the 6.7L Power Stroke, and it replaces the 6R140-SE service tool. It is the step between taking a new ring out of the bag and lowering the shaft or drum into the case.
The 6R140 is a clutch-to-clutch unit. Each clutch piston is fed through drilled passages in the shafts and drums, and solid scarf-cut Teflon rings seal those passages where a rotating part meets a stationary bore. If one ring leaks, oil bleeds from one circuit into the next. Because shift timing is controlled entirely by solenoid pressure into those circuits, even a small leak shows up as a slow, soft or flared apply, and the module chases it with adaptive changes it cannot fully correct.
New Teflon rings are oversize out of the package. The expander lets you open a ring just enough to slide it over the land without stretching it, and the resizer compresses it back down to bore size so it enters the bore cleanly.
Rule out the simple causes first. Pressure-check the unit and compare against spec, and scan for solenoid and speed sensor codes, since those mimic a leak. Our 6R140 delayed engagement guide covers the filter seal, pump and valve body checks, and the pressure control solenoid guide explains how a weak line pressure solenoid looks on a scan tool. If those check out, a ring leak is likely. On the bench, air-check each clutch: a hiss at the shaft, rather than at the piston, points to a ring. Sonnax technicians also note that ring damage often comes with a cracked 4-5-6 housing weld, so inspect that drum closely.
This set fits the Ford 6R140 only, as used in 2011-up Super Duty 6.7L applications. It is not sized for the 6R80, 10R80 or 10R140, so read the transmission code from the tag on your case before you order. If you are not sure which unit you have, send your year and VIN and we will confirm it. All of our parts and tools for this transmission are on the 6R140 collection page.
Do the rings during a full overhaul with a 6R140 rebuild kit, then refill with Mercon LV and reset adaptives with a scan tool.
| Type | Sealing ring expander and resizer tool set |
| Fits transmissions | Ford 6R140 TorqShift 6-speed automatic |
| Vehicle applications | Ford F-250, F-350, F-450, F-550 Super Duty 6.7L, 2011 and up |
| Replaces | 6R140-SE |
| Not compatible with | 6R80, 10R80, 10R140 |
| Brand | AUTOVIC |
It replaces the 6R140-SE sealing ring expander and resizer service tool for the Ford 6R140.
No. It is sized for the 6R140 only and is listed as not compatible with the 6R80, 10R80 or 10R140.
New Teflon rings are oversize. Pushing an oversize ring into the bore can roll, cut or crack it, which causes a cross-leak and a soft or slipping clutch apply.
A few minutes is enough for the ring to take its set at bore diameter. Check that it turns freely and sits flush before assembly.
Yes. After a rebuild, fill with Mercon LV, reset the adaptive tables with a scan tool, and drive the truck through all shifts.
