6R60 Overhaul Kit 2006-2008

The 6R60 is the six-speed behind the V8 Ford Explorer, Explorer Sport Trac and Mercury Mountaineer, and by now most of them have well over 100,000 miles on the original seals. When one starts leaving drips on the driveway, takes a long second to engage Reverse on a cold morning, or flares between gears once it is hot, the rubber and Teflon inside are usually done. This is the Precision International KP37900J overhaul kit, cataloged for 6R60 and 6R75 transmissions built from 2006 through 2008 in Ford and Mercury vehicles, and it is the gasket and seal set an early 6R60 rebuild starts with.

What the overhaul kit does in a 6R60

Ford built the 6R60 in-house under its agreement with ZF, and it shares the ZF 6HP26 layout: a Lepelletier planetary geartrain with three driving clutches (A, B and E) and two brake clutches (C and D). Every forward gear uses two of those five packs at once, so each pack works in more than one gear. Oil reaches the rotating drums through sealing rings, and each piston holds pressure with a molded seal. Once those harden, a pack fills slowly and slips, and because the packs are shared, one bad seal can show up in two or three gears. The overhaul kit replaces the piston seals, sealing rings, O-rings and gaskets in every circuit, plus the external seals and gaskets that cause leaks. It does not include frictions or steels.

Symptoms that point to tired seals

• Fluid leaks at the pan, the case connector or the converter seal
• Slow engagement into Drive or Reverse after sitting overnight, better once warm
• Slip or engine flare on upshifts that grows with fluid temperature or trailer weight
• Low fluid and a burnt smell on a unit that has been leaking for a while

How to confirm before you tear it down

Check the fluid level the correct way first, at operating temperature, since a low 6R60 slips exactly like a worn one. Then scan for codes. The family runs its solenoids and sensors through a control unit mounted on the valve body, and an electrical fault or a solenoid that has drifted out of calibration can feel like a mechanical slip. Our 6R family common problems guide walks through the electrical checks, and the shift problems diagnosis guide covers the harsh-shift and timing complaints that new seals will not cure. If the electrical side is clean and the unit still leaks, slips or engages late, it needs the reseal.

Fitment: 2006-2008 6R60

The KP37900J is listed for 2006-2008 6R60 and 6R75 transmissions. On the 6R60 side that is the 4.6L V8 Explorer, Explorer Sport Trac and Mountaineer; the V6 versions of those SUVs used a five-speed, so read the tag on the case before ordering. A 6R60 is easy to tell from a 6R80 once it is apart: Transmission Digest notes the 6R60 stator support has a front bushing, its input shaft has a bushing journal, and the input carries two sealing rings where the 6R80 carries three. Ford also changed drum and hub part numbers during the run, so compare each seal and ring to the one you remove. If you have a 2009-2010 6R60, or you are unsure, send your year, model and VIN and we will match it. The whole family is on the 6R60, 6R75 and 6R80 collection page.

Install notes

• Soak every piston seal in clean fluid and size the Teflon rings on their journals with assembly gel before the drums go together.
• Inspect the overdrive (E) clutch hub. The early design was a stamped hub welded to a shaft and failed often enough that Ford replaced it with a two-piece steel hub.
• Look over the input planet while it is out. Early units used a three-pinion carrier and later ones a four-pinion carrier with a matching retainer; our 6R60 planetary is there if yours is noisy or pitted.
• If the clutches are burnt, step up to the 6R60 kit with frictions and steels rather than reusing plates.
• Shift feel lives in the valve body. Replace worn solenoids with the 2006-2011 6R60 solenoid kit while it is on the bench.
• Air-check each clutch circuit, refill with the Ford fluid listed in your owner guide (no additives), then clear adaptives and drive the relearn.

Does this kit fit a 2007 Ford Explorer V8?

Yes, if it has the 6R60 six-speed. The kit is cataloged for 2006-2008 6R60 and 6R75 units. V6 Explorers of that era used a five-speed and need a different kit, so read the transmission tag first.

Are frictions and steels included?

No. The KP37900J is the overhaul set of seals, sealing rings, O-rings and gaskets. If the clutch packs are burnt or worn, choose our 6R60 kit that adds frictions and steels.

How do I tell a 6R60 from a 6R80 on the bench?

The 6R60 stator support has a front bushing and its input shaft carries two sealing rings. The 6R80 has no front stator bushing, a larger bore and three input sealing rings.

Will new seals fix a harsh shift?

Not by themselves. Harsh or badly timed shifts on this family are often solenoid or calibration problems. Scan for codes and check the valve body before a rebuild.

What fluid goes back in after the rebuild?

Use the Ford automatic transmission fluid listed in your owner guide for your exact year, check the level at operating temperature, and do not add supplements.

Does the computer need to relearn after the overhaul?

Yes. Clear the transmission adaptive values with a scan tool and complete a relearn drive so the computer learns the new clutch fill times.

• 6R80 Common Problems and Fixes
• 6R80 Expedition Shift Problems: Diagnosis and Fix
• 6R80 Expedition Common Problems and Fixes