U660F Master Rebuild Kit 2006, new and ready to install. Fits the U660F. Ships fast from the USA.
If your all-wheel-drive Toyota or Lexus V6 is slipping between gears, flaring on upshifts, or the pan came off full of dark fluid and clutch material, the transaxle is almost certainly past the point of a fluid change. This new U660F master rebuild kit is listed for the 2006 production start of the U660 family, so it is aimed at the earliest units: the ones that have the most miles on them today and are now landing on the bench for a full overhaul.
The U660F is the all-wheel-drive version of Toyota and Aisin's U660E six-speed transaxle, the V6 unit that Gears Magazine notes first appeared in the Camry and Lexus ES350 and later spread to Avalon and Venza. The F suffix adds the transfer output that drives the rear axle; the gear train inside is the same family. According to ATSG, that gear train uses two driving clutches (C1 and C2), three brake clutches (B1, B2 and B3) and one one-way clutch (F1), working through a Ravigneaux planetary set and an underdrive planetary set. Every one of those clutches is applied by hydraulic pressure against a piston sealed with rubber lip seals and fed through sealing rings. A master kit is the box of soft parts that renews that whole sealing and friction system in one job, instead of buying seals, gaskets and frictions line by line.
Not every harsh or shuddering U660F needs to come apart. Gears Magazine points out that a 25-50 mph shudder is usually a lockup clutch, valve body or fluid issue, and that harsh coasting downshifts can come from a carboned throttle body or a slow MAF sensor. Scan every module, check the fluid level at the correct temperature, and road test in Manual 3, which disables flex lockup. Our U660E/U760E problems and service guide walks through those checks. If the fluid is burnt and the slip is real, a master kit is the right call.
This kit is listed for the U660F with a 2006 date, which lines up with the very first production of the U660 family; ATSG's application list starts the Lexus ES350 in 2006 even though the first North American models were sold as 2007s. Toyota made running changes to this transaxle over its life, so read the ID tag on your case and confirm it says U660F before you order. If you are not sure, send us your year, model and VIN and we will check it against the unit. If your vehicle is a later build, compare the U660F master rebuild kit for 2006-2011, or browse everything for this family on our U660E/U660F/U760E parts page.
On an early U660F, inspect the hard parts before you commit to reassembly. Gears Magazine reports that the U660E family is prone to wear in the case bore that supports the main gear train bearing, which leads to bushing wear and, in extreme cases, a broken converter input spline. If the outer bearing race moves in the case at all, the case has to be repaired or replaced. Check the drums for scoring, measure bushings, set clutch clearances to the factory spec with the selectives, and soak new frictions in ATF before installation. While the valve body is off, vacuum test the lockup and solenoid modulator bores; worn bores will cook a fresh set of clutches. A U660F shift kit is a sensible add-on at this stage.
Refill only with Toyota WS fluid such as our Genuine Toyota WS ATF 6-quart case, then set the level at the overflow plug in the 185-194 F window that Toyota's bulletin specifies. Finish with an ECT adaptive reset using a scan tool that can actually perform it, and drive the vehicle cold to hot so the computer relearns shift pressures on the new clutches. Our U660E fluid type and capacity guide covers the level procedure step by step.
| Fits | U660F 2006 |
| Part type | Master Rebuild Kit |
| Condition | New |
| Brand | OEM |
| Reference | U660E |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
This listing is for the U660F, the all-wheel-drive version. The internal clutches are the same family, but check the ID tag on your case and send us your year and VIN before ordering if your unit is a U660E.
Possibly. The U660 family started production in 2006 for early 2007 models. Match the ID tag and part numbers on your unit, or send us the VIN and we will confirm fit or point you to the 2006-2011 version.
Toyota WS automatic transmission fluid (part number 00289-ATFWS). Set the level at the overflow plug with the fluid between 185 and 194 F, as Toyota's level-adjustment bulletin specifies.
Yes. Clear codes in all modules and run Toyota's ECT adaptive reset. Gears Magazine warns that some aftermarket tools show the function but do not actually clear the adapts, so verify that shift feel changes on a cold-to-hot drive.
Inspect the case bearing bore, drums and bushings, replace the filter, and vacuum test the valve body. Many builders add a shift kit and service or replace the torque converter at the same time.
