U660E Clutch Drum 2010

A V6 Camry, Avalon, Venza or Lexus ES350 that slips or flares in first through fourth, or loses fifth and sixth after the 4-5 shift, usually has a problem inside the forward and direct clutch drum. This listing is the late-design U660E forward/direct drum for 2010 and later units, remanufactured and delivered loaded: the drum and input shaft come built up with new forward and direct clutch plates, new steels and new pistons, so it drops into the case as one assembly instead of a pile of parts to stack and clearance.

What this clutch drum does in a U660E

ATSG's technical information lists two driving clutches in the U660E, C1 and C2, plus three brake clutches and one one-way clutch. Both driving clutches live in this drum. On ATSG's component application chart C1, the forward clutch, is applied in first through fourth gear, and C2, the direct clutch, is applied in fourth through sixth. That means this one assembly carries engine torque in every forward gear. The input shaft in the center of the drum is splined to the converter turbine, and fluid fed through the shaft's sealing rings strokes the pistons. If those ring lands, the drum bushing or a piston seal wear, apply pressure leaks away and the pack slips. According to the listing, this assembly has four forward clutches and three direct clutches and a shaft about 9 1/4 inches long.

Symptoms of a worn forward/direct drum

• Slipping or a delayed bite in first through fourth, which points at C1
• Flare on the 4-5 shift, or slipping in fifth and sixth, which points at C2
• No forward movement while Reverse still works
• Burnt friction material or metal flakes in the pan and on the magnets
• Gear ratio or clutch slip codes once the computer sees input and output speeds disagree

How to confirm before you buy

The case has dedicated pressure taps for the C1 and C2 clutches, as ATSG's pressure tap chart shows. A gauge on those taps tells you whether the drum is getting full pressure. If pressure is right and the clutch still slips, the problem is inside the drum. If pressure is low on both taps and on the line tap, look at the pump and valve body first. Also check the fluid level hot, because low WS fluid can mimic a worn clutch. Gears Magazine warns that the wrong fluid can produce flaring shifts and pressure solenoid codes, and that a failing case-mounted TCM can set U0402. Our U660E and U760E problems guide explains how to separate a valve body fault from a mechanical failure.

Fitment

This drum is the late version for 2010 and newer U660E transmissions, the front-drive V6 six-speed; the same late drum is offered for the all-wheel-drive U660F as a separate listing. Earlier units can use a different drum, and the four-cylinder U760E uses a different design that looks similar, so lay your old drum next to the photo and compare the shaft length, spline count and sealing ring grooves. If you are unsure, send us your year, model and VIN and we will confirm. Every part for this family is on the U660E collection page.

Install notes

• Clean the case, cooler and lines. Clutch debris left in the cooler will contaminate a new drum and valve body.
• Inspect the case bearing support bore. Gears Magazine reports wear there on the U660E under V6 torque; if the outer race moves, the case must be repaired or the new drum will run off centerline.
• Air-check C1 and C2 through the case passages before the valve body goes on, and confirm clutch clearance against the service manual.
• Use new sealing rings on the input shaft and lube them with WS fluid.
• Fill with Toyota WS, set the hot level per the bulletin covered in our U660E fluid guide, and run the ECT memory reset.

Most drum failures follow an overheat, so finish the job with the U660 master rebuild kit for the other packs and gaskets, and a U660E valve body if pressure tests showed bore wear.

Does this drum come with clutches installed?

Yes. It is a loaded assembly with new forward and direct clutch plates, new steels and new forward and direct pistons installed, according to the listing.

Will it fit a 2008 or 2009 U660E?

This is the late drum for 2010 and newer units. Earlier transmissions can use a different version, so compare your old drum's shaft and grooves with the photo, or send us your VIN to confirm.

Is the U760E drum the same?

No. The four-cylinder U760E drum looks similar but is a different part. Confirm the tag on your transmission reads U660E before ordering.

Which gears does this drum affect?

The forward clutch (C1) applies in first through fourth, and the direct clutch (C2) applies in fourth through sixth, so this drum carries torque in every forward gear.

What fluid and relearn does it need?

Refill with Toyota WS, set the level hot through the overflow plug, then clear the adaptive values with a scan tool that runs Toyota's ECT memory reset and road test cold to hot.

• Toyota/Aisin U660E and U760E: Shudder, Valve Body Wear, and the WS Fluid-Level Procedure
• U660E Fluid Type, Capacity and Service Interval