Seal, gasket and sealing-ring set for Toyota and Lexus U660E six-speed transaxles, 2007-up, with the reusable Duraprene molded pan gasket.
Owners of a V6 Camry, Avalon, Sienna, Highlander, Venza, RAV4 V6, Lexus ES 350 or RX 350 usually land here because the U660 six-speed has started leaking, cross-leaking or slipping and a teardown is on the calendar. This is the TransTec overhaul kit, part number 81000612 (DP 2551), for 2007-up U660E and U660F transaxles. It is the complete sealing package for the unit, and it comes with a Duraprene molded pan gasket in place of the usual paper one.
The U660E is Aisin's six-speed front-drive transaxle built for the 3.5L V6, and the U660F is the all-wheel-drive version of the same gearbox. Every shift depends on pressure staying where it is sent: from the pump, through the valve body, across the sealing rings into the spinning clutch drums and behind each apply piston. The kit replaces the lip seals, O-rings, sealing rings, gaskets and, where the unit uses them, molded rubber piston seals. It does not contain frictions, steels, bushings or a filter. If the clutches are burnt you need a master kit as well; if the unit is coming apart because it leaks or has lost pressure through hardened seals, this is the core of the job.
The U660 pan is removed for every filter service and for any valve body or solenoid work. A paper gasket tends to tear and bond to the flange, which means scraping the case with the transaxle still in the car. The Duraprene gasket is rubber bonded to a carrier, seals dry on a clean flange, and comes off with the pan in one piece, so the next service is a pan-drop instead of a cleanup job.
Check the fluid properly first. The U660 has no dipstick, and Toyota's bulletin sets the level through the overflow plug at 185-194 F, so a low or overfilled unit is common after a quick service. A shudder at light throttle in the 25-50 mph range is usually lockup rather than seal wear; Gears Magazine notes this family is also known for case bearing-bore wear and converter input-spline breakage that a seal kit will not cure. Sonnax's vacuum test guide lists the valve body bores that wear on the U660E and U660F, and our U660E and U760E problems guide explains how to separate a valve body fault from an internal leak.
TransTec catalogues this kit for U660E and U660F transaxles from 2007 on: Camry V6, Avalon, Sienna, Highlander, Venza, RAV4 V6, Lexus ES 350 and Lexus RX 350. Four-cylinder models with the U760E use a different kit. Read the model code on the transaxle tag, or send us your year and VIN and we will confirm the match. Parts for the whole family are on the U660E and U760E parts page.
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Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
No. It is the TransTec 81000612 sealing kit: seals, O-rings, sealing rings, gaskets and the Duraprene pan gasket. Frictions, steels, bushings and the filter are sold separately.
Yes, the kit covers both the front-drive U660E and the all-wheel-drive U660F from 2007 on. Confirm the transaxle tag if your vehicle could have the four-cylinder U760E instead.
It is built to come off with the pan without tearing, which makes the next filter service easier. Inspect it for cuts or flattening at each removal and replace it if it no longer seals cleanly.
Plan on a new filter, a cooler flush and a close look at the valve body bores and solenoids. If the frictions are glazed or the steels are blued, add a master rebuild kit.
ATSG lists 6.57 L (6.94 US qt) total including the differential, using Toyota WS only. After a rebuild, fill and then set the level hot through the overflow plug at 185-194 F.
