Street Smart - May - 2018

Toyota/Lexus U880E: Beyond the Valve Body, Part 2

Welcome back for part 2 of beyond the valve body for the U880E. In the January/ February issue, we disassembled this unit down to the C-1 clutch.

One piece of information that I left out was servo identification and servo travel. It’s important to be aware of what the servo travel should be (figures 1A, 1B & 1C). Using a caliper gauge, measure the Travel of the B-1 brake piston rod while applying compressed air (30-55 psi). Standard Travel: 5.5 to 6.0 mm (0.217 to 0.236 in.). If the Travel is not as specified, select an appropriate B-1 brake piston rod so that the Travel will be within the specified range from chart. If servo travel isn’t correct, select a pin from the chart to adjust it properly.

So let’s pick up from there. At this point, we can remove the counterdriven gear by just lifting it from the transaxle. The same is true with the differential case assembly; you can lift it from the transaxle (figure 2). This will expose all six bolts you’ll need to remove so you can remove the front planetary gear subassembly from the case.

  1. With the front planetary removed from the transaxle, this is a good time to remove the output sensor to prevent damaging it. Notice the location of the spacer (figure 3).
  2. Lift the sun gear from the rear planetary and set it aside.
  3. Remove the snap ring that holds the one-way clutch assembly and rear planetary gear assembly in the transaxle. This will lift right out (figure 4).
  4. With the planetary and one-way clutch removed, notice the hold and rotation directions for the one-way clutch. (Figure 4B)
  5. Remove the B-2 brake. Figure 5 shows what the clutch clearance should be, and includes a chart of the flanges that are available to get the clearance right.
  6. Lift the C-2 clutch assembly from the transaxle.
  7. Figure 6 is an exploded view of the C-2 clutch and clutch clearance with a chart on the flanges that are available to get the right clutch clearance.
  8. Now for the B-2 brake piston removal. This is one place we recommend using the special service tool. It’s important to put the snap ring in properly; failing to do so could damage the return springs.

Toyota’s part number for this tool is SST 09950-70010. You can also look through the GEARS buyer’s guide for suppliers.

The B-2 brake clutch return springs and piston are held in place by the snap ring (figure 7). You must install the snap ring with the opening facing the case walls; not the tooth gaps. This will make sure the snap ring holds its place in the case.

Well, that covers the internals of this unit. With this information, you should be ahead of the game and on your way to a successful rebuild. But there are still a couple things you need to do.

Transmission Fluid Fill

One of the biggest problems with this unit appears when someone doesn’t use the right type of transmission fluid. This transaxle requires genuine ATF WS transmission fluid.

  1. Remove the refill plug and overflow plug.
  2. Fill the transaxle through the refill hole until fluid begins to trickle out of the overflow tube.
  3. Temporarily install the overflow plug.
  4. Allow the engine to idle with the air conditioning off.
  5. Move the shift lever through entire gear range to circulate the fluid.
  6. Recheck fluid.

With Techstream

  1. Connect Techstream to the DLC3.
  2. Turn the tester on.
  3. Enter the following menus: Powertrain / ECT / Data List.
  4. Check A/T Oil Temperature 1.
  5. Allow the engine to idle until the fluid temperature reaches 39ºC (102ºF).

Without the Techstream (Using D Shift Indicator)

  1. Connect terminals 4 and 13 in the DLC3.
  2. Move the shift lever back and forth between N and D at 1.5 second intervals for 6 seconds.
  3. The D shift indicator on the combination meter comes on for 2 seconds when the fluid temperature is within the appropriate range.
  4. Add fluid until it comes out the overflow plug. Wait until the overflow slows to a trickle.
  5. Install the overflow and refill plugs using new gaskets.

ECM Reset

You must reset the ECM adapts before driving the vehicle after installation, using an OE or approved scan tool. Failure to do so can result in slipping or binding shifts and failure of the transmission after only a short road test.

  1. Verify that computer has latest software calibrations.
  2. Clear codes
  3. Reset adaptive learn
  4. Rescan after road test and make sure no codes have come back.

That’s it for going beyond the valve body. And that’s not just smart… that’s street smart!