A/T - A40VB Valve Body Interchange
BULLETIN: # 9001002SUBJECT: VB Interchange
DATE: Jan 1990
TRANSMISSION: Toyota A-40
TOYOTA A-40 VB INTERCHANGE
A-40 VALVE BODIES
Shift quality and timing complaints on Toyota rear wheel drive transmissions can many times be traced to a mis-match of throttle cams, plungers, and springs.
From 1973 to the present there are six different throttle cams, four different throttle plungers and four different plunger springs. The correct arrangement is determined by the transmission type, production date, and car model.
THROTTLE CAMS
The throttle cam is used to coordinate the rate at which the throttle pressure increases and to properly time the detent circuit (passing gear).
By changing throttle cam and plunger combinations it's possible to open the detent circuit with as little as 24 mm of cable travel or as much as 44 mm of cable travel.
Each cam has a number stamped on it. Use Figure 1 to determine the Toyota part number for each cam.
THROTTLE PLUNGERS
Figure 2 shows three of the four throttle plungers and their respective part numbers.
The first plunger design change was made by adding 3 mm to the plunger length. This moves the plunger spring and throttle valve 3 mm and shortens the cable travel required to open the detent circuit This valve (2nd design) is identified by a 2.5 mm groove between the two spools.
The 3rd design valve had a .4 mm spring seat added to it. Once again this moves the plunger spring and throttle valve but does not change detent timing. This valve (3rd design) is identified by a 2.8 mm band between the two spools.
PLUNGER SPRINGS
The 4th plunger is ONLY used in A43DE Transmissions and is identified by an aluminum sleeve attached to it. (Part # 35408-30020)
Plunger springs vary in length and number of coils and are identified by color. Different springs change the position of the throttle valve which then changes throttle pressure thereby having a direct effect on shift - timing and quality. Figure 3 identifies the four springs currently in use.
PUTTING IT ALL TOGETHER
Using Figure 4 you can now select the proper combination of throttle components for any application. As an example, a1980 A-40D in a Celica would use a # 4 cam, a 1st design plunger and a white plunger spring.
BULLETIN RECAP
Toyota A-40 VB Interchange
^ Follow these steps:
^ Determine car model
^ Determine production date (Month and Year)
^ Determine transmission type (3 speed, 4 speed or A-43DE)
^ Use figure 4 to select proper cam, plunger and spring
^ Use figures 1-3 to I.D. throttle components and/or select proper part numbers
FOR ADDITIONAL INFORMATION:
TRANSMISSION DIGEST November 89, Page 12