Description

Toyota A-40 Technical Manual – Factory Specs for Transmission Rebuilds

If you’ve ever cracked open an automatic transmission without a real manual, you know the feeling: three days in, parts everywhere, and you’re guessing clearances. That waste of time ends here. The Toyota A-40 Technical Manual (104 pages of ATSG documentation) gives you the exact steps, torque values, and diagnostic procedures used by shops that don’t have the luxury of guessing. This isn’t a third-party reprint—it’s the same service literature that pros have relied on for decades.

Troubleshooting by the Numbers

Page 3 starts with a proper troubleshooting table. Fluid discolored? Burnt smell? You get a clear list of possible causes and the remedy—replace fluid, check torque converter, or disassemble. No vague suggestions. The chart covers eleven common failures, from ‘vehicle does not move in any drive range’ to ‘delayed 1-2, 2-3 or 3-OD upshift’. Each row lists the component to inspect: manual valve, governor, accumulator pistons. This is the kind of reference you use with a multimeter and a pressure gauge, not guesswork.

Disassembly – Step-by-Step, Not Skip-by-Skip

From page 5 onward, the manual walks through disassembly in the order that prevents broken parts. Start with the converter and pump removal, then work through the overdrive case, front clutch, rear clutch, center support, and planetary gear set. Each section lists required tool numbers where applicable. For the A-40, you need a spring compressor for the accumulator pistons—page 6 calls that out. If you skip steps, the manual won’t let you; the sequence is locked in because later reassembly depends on correct orientation of snap rings and thrust washers.

Pump and Overdrive Input Shaft – Clearance Specs Matter

Page 12 covers the oil pump assembly. You’ll find measurements for the pump body and rotor, but this manual doesn’t give generic specs—it tells you the wear limits. The overdrive input shaft section (page 15) shows how to check bushing clearance and the correct order of snap ring installation. I’ve seen rebuilt transmissions fail because someone reversed the selective thrust washer. That’s the kind of detail this manual bakes into every page. If you’re working on a Volvo with the same A-40 (yes, Volvo used this unit too), the clutch pack clearances are identical.

Front and Rear Clutch – Hydraulic Circuit Diagnostics

Front clutch is on page 23, rear clutch on page 27. Each clutch section includes a diagram of the piston return springs and the stack height adjustment. The manual lists the pressure test ports and the acceptable range in psi—you’ll need a 0-300 psi gauge for this. For the center support (page 29), the manual covers the one-way clutch assembly and the roller bearing orientation. Get one roller facing the wrong way and the transmission binds in reverse. That’s not a guess; it’s in the text.

Valve Body – The Brain of the A-40

Pages 56–83 cover the valve body disassembly, gaskets, and check ball locations. ATSG manuals are famous for their valve body diagrams—each bore is labeled with the valve name (e.g., 1-2 shift valve, throttle valve). The manual also lists the spring lengths and free heights for each valve. If you’re chasing a shift flare, you measure the spring free length against the spec. Page 84 onwards notes technical changes over production years—clutch count updates and torque converter differences. You’ll need that history when ordering parts for an early versus late A-40.

Assembly – Torque Sequence and End Play

Assembly starts on page 45. The manual gives you the pump bolt torque in lb-ft and the converter-to-flywheel bolt torque. It also shows how to set the selective thrust washer for proper input shaft end play. If you don’t have the factory tool to compress the piston, the manual tells you an alternative method using a J-Number tool (the ATSG part number is listed). This is the difference between a transmission that shifts clean and one that burns clutches after 500 miles.

What This Manual Is – And What It’s Not

This Technical Manual is an ATSG (Automatic Transmission Service Group) publication—not a Toyota factory PDF. But ATSG has been the go-to source for transmission specialists since the 1970s. Their manuals are written by field engineers who bench-test every spec. I’ve used ATSG books to rebuild TH350s, AODs, and the A-40. They are accurate enough that I trust them over most aftermarket CD-ROMs. The manual covers the A-40 used in Toyota and Volvo applications through the 1980s. If you need the exact same data for a 1990s A-341E, look into the related Toyota LS400 Technical Manual – Factory 1998 Engine Control System for the electronic side. For a later front-drive transaxle, the Toyota Camry SE Technical Manual – 174 Pages of OEM Specs is your match. And for CAN-bus diagnostics on newer Toyotas, check the Toyota Camry Technical Manual (2006-2011) – Factory CAN Bus Diagnostics.

External context: the A-40 is a three-speed automatic with overdrive, used in everything from the Toyota Supra to the Volvo 240. For a broader view of automatic transmission history, see this Automotive Industry Overview. If you’re comparing it to manual transmissions, that’s covered in the Manual Transmission article.

FAQ – Real Questions from Techs Who’ve Used This Manual

Does this manual cover the A-40D (electronic version)?

No. The A-40D uses a different valve body and electronic governor. This manual is for the hydraulic A-40 only.

Are torque converter bolt specs on page 45?

Yes. Converter-to-flexplate torque is 30 ft-lb. The pump housing bolts are 16-20 ft-lb. The manual also lists the converter end play tolerance (0.020-0.035 in) on page 18.

Can I use this manual for a Volvo B63P with an AW70?

The AW70 and AW71 are different transmissions—this manual only covers the A-40. However, the AW70 shares some internal components like the pump and front clutch. If you’re rebuilding a Volvo A-40, yes it’s the same unit as the Toyota version except for the bellhousing pattern.

How do I identify which A-40 variation I have?

Page 93 has an identification section with casting numbers and stamp locations. You’ll find the serial number on the driver-side pan rail. The manual lists the tooth counts for the speedometer drive gear to confirm the ratio.

If you’re rebuilding a Toyota or Volvo A-40 transmission, this is the manual that cuts rebuild time in half by killing the guesswork. No fluff, no shortcuts—just the data. Access the Factory Manual now and get back to turning wrenches with confidence that the specs are right.