Bonded clutch piston kit for the Toyota AB60E/AB60F 6-speed in 2007-2017 Tundra, Sequoia, Land Cruiser and LX570. Replaces 35621-0C020.
A 5.7L Tundra, Sequoia, Land Cruiser or LX570 with a tired AB60E or AB60F often comes in with the same story: the transmission was rebuilt once, it shifted fine for a while, and now it flares between gears or burns a clutch pack again. When that happens, the frictions usually get the blame, but the rubber on the pistons that apply those clutches is just as likely to be the cause. This kit supplies new bonded pistons for the AB60 6-speed so the clutch apply circuits seal like they did from the factory.
The AB60 uses four clutches (C1 to C4) and four brakes (B1 to B4) to make six forward speeds and reverse. Each of those packs is squeezed by a hydraulic piston. On a bonded piston the rubber sealing lip is molded directly onto the steel, rather than being a separate seal that sits in a groove. That design is accurate and compact, but it means the seal cannot be replaced on its own. After years of heat cycles the lip hardens, shrinks or starts to peel away from the metal, and apply oil leaks past it. A clutch that only sees part of its apply pressure slips, glazes and eventually burns, even with new frictions. The kit carries Toyota numbers 35621-0C020, 35669-0C020 and 35602-34010 and crosses to K86900E-99, 77960AK and 157960K; the Precision K86900E-99 kit is sold as the AB60E/AB60F bonded piston kit.
Start with the basics: correct fluid level with Toyota WS, a scan for stored codes, and a line pressure check against published idle and stall figures. If pressure is in spec but a clutch still slips, the leak is inside the clutch circuit. On the bench, air-check every circuit with the unit apart: a good piston moves with a crisp thump and holds, while a leaking one hisses. Inspect each lip with a fingernail; if the rubber lifts at the edge, is cracked or feels hard, replace the piston. A burnt C2 clutch is a well-documented AB60 failure, so pay extra attention to that circuit.
Listed for the Toyota AB60E (2WD) and AB60F (4WD) 6-speed in the 2007-2017 Tundra, 2008-2017 Sequoia, 2008-2011 and 2013-2015 Land Cruiser, and 2008-2011 and 2013-2017 Lexus LX570. Later trucks through 2021 use the same AB60 family, but parts can change inside a production run, so lay the pistons in the photos next to the ones you remove before you start assembly, or send us your year and VIN to check. All of our AB60 parts are listed under Aisin and Toyota transmissions.
Clean each drum and bore and check for scoring where the lips ride; a new piston will not seal in a scratched bore. Coat the lips with assembly gel or clean Toyota WS, start each piston square and press it in evenly with a slight twist, never by hammering one side. Re-use the return springs only if they are straight and the retainers are flat. Air-check each circuit again once the packs are stacked, then fill with Toyota WS ATF and set the level hot using the overflow procedure.
Pistons are only one part of a lasting rebuild. Pair them with the AB60E overhaul kit for gaskets, seals and frictions or the AB60E master rebuild kit if you also need steels. If the direct drum is scored, the AB60E clutch drum replaces it, and a fresh AB60E filter kit keeps debris from the old failure out of the new unit.
| Type | Bonded clutch piston kit |
| Fits | Toyota AB60E, AB60F 6-speed |
| Vehicles | Tundra 2007-2017, Sequoia 2008-2017, Land Cruiser 2008-2011/2013-2015, LX570 2008-2011/2013-2017 |
| Part numbers | 35621-0C020, 35669-0C020, 35602-34010, K86900E-99, 77960AK, 157960K |
| Weight | 2.5 lb |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
It is listed for the AB60E and AB60F in the 2007-2017 Tundra, 2008-2017 Sequoia, 2008-2011 and 2013-2015 Land Cruiser, and 2008-2011 and 2013-2017 Lexus LX570. Compare the pistons with yours or send your year and VIN to confirm.
The sealing lip is molded to the steel and hardens with age. A leaking piston leaves the clutch short on apply pressure, so new frictions can still slip and burn. Replacing the pistons during the rebuild removes that risk.
No. On a bonded piston the rubber is molded onto the steel, so the whole piston is the replacement part.
Toyota WS automatic transmission fluid, the factory fill for the AB60E and AB60F. Set the level hot using the overflow check procedure.
Air-check each clutch and brake circuit with low-pressure shop air. You should hear the pack apply firmly and release with no hissing leak.
Most rebuilders install it with an overhaul or master rebuild kit and a new filter. Inspect the drums for scored bores, because a new piston will not seal in a damaged bore.
