2007 Lexus SC 430FACTORY OEM SERVICE PROCEDURE

Automatic Transmission Unit: Inspection

  1. INSPECT 1st AND REVERSE BRAKE RETURN SPRING SUB-ASSEMBLY 
    1. Using a vernier caliper, measure the free length of the spring together with the spring seat.

      Standard free length: 23.74 mm (0.935 in.) 

      If the free length is shorter than the standard free length, replace the brake piston return spring sub-assembly.

      Fig 1: Measuring Free Length Of Spring
      G05289918Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  2. INSPECT REAR PLANETARY GEAR ASSEMBLY 
    1. Using a feeler gauge, measure the rear planetary gear pinion thrust clearance.

      Standard clearance: 0.2 to 0.6 mm (0.008 to 0.024 in.) 

      If the clearance is not as specified, replace the planetary gear assembly.

      Fig 2: Measuring Rear Planetary Gear Pinion Thrust Clearance
      G05289919Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Using a caliper gauge, measure the inside diameter of the rear planetary gear bushing.

      Standard inside diameter: 20.025 mm (0.7884 in.) 

      If the inside diameter is not as specified, replace the rear planetary gear assembly.

      Fig 3: Measuring Inside Diameter Of Rear Planetary Gear Bushing
      G05289920Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  3. INSPECT PACK CLEARANCE OF 1st AND REVERSE BRAKE PISTON 
    1. Make sure that the 1st and reverse brake piston moves smoothly while applying compressed air intermittently into the transmission case.
      Fig 4: Applying Compressed Air Into Transmission Case
      G05289921Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Using a vernier caliper, measure the level difference (length A) between the upper surface of the brake apply tube and the hitting surface of the No. 4 brake flange at both ends across the 1st and reverse brake piston diameter, and calculate the average.
      NOTE: The 1st and reverse brake piston must be securely installed to the end face of the transmission case.

      HINT:

      Length A = 22.05 to 22.91 mm (0.8681 to 0.9020 in.)

      Fig 5: Measuring Level Difference (Length A) Between Upper Surface Of Brake
      G05289922Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Using a vernier caliper, measure the combined thickness (length B) of the brake flanges, the 4 brake plates and the 4 brake discs at both ends across the diameter, and calculate the average.

      HINT:

      Length B = 23.11 to 23.89 mm (0.9098 to 0.9405 in.)

      Pack clearance = Length A - Length B - 0.22 mm to 1.8 mm (0.0087 to 0.071 in.)

      Standard pack clearance: 0.4 to 0.7 mm (0.016 to 0.028 in.) 

      Fig 6: Measuring Combined Thickness (Length B) Of Brake Flanges, Brake Plates And Brake Discs
      G05289923Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    4. If the pack clearance is outside the standard, select and install a brake flange that brings the pack clearance within the standard.

      HINT:

      There are 8 types of flanges that can be used to adjust the pack clearance. Select the one with the most appropriate thickness.

      Standard thickness H 

      THICKNESS REFERENCE CHART

      No. Thickness H No. Thickness H
      0 0 mm (0 in.) 8 0.8 mm (0.03150 in.)
      2 0.2 mm (0.00787 in.) 10 1.0 mm (0.03937 in.)
      4 0.4 mm (0.01575 in.) 12 1.2 mm (0.04724 in.)
      6 0.6 mm (0.02362 in.) 14 1.4 mm (0.05512 in.)
  4. INSPECT NO. 4 BRAKE DISC 
    1. Replace all discs if one of the following problems is present: 1) a disc, plate or flange is worn or burnt, 2) the lining of a disc is peeled off or discolored, or 3) grooves or printed numbers have even a little bit of damage.
      NOTE: Before assembling new discs, soak them in ATF for at least 15 minutes.
Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

Shop Manual-Ready ToolsCompare Repair QuoteQuote Shield Pro

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

Rather have a pro handle this?

A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.

Comes to youSame-day available12-month warranty
Get a Free Quote

No obligation. See pricing before you book.