Harsh Downshifting 4-2 or 3-2 Etc.....

Effective Serial Numbers:

REMEDY:
1. On transmissions produced before effective serial numbers shown above, remove valve body and carefully disassemble to separate two halves. Replace valve body small intermediate plate.

!Observe extreme cleanliness

2. Install automatic adjusting B1 piston, part no. 124 270 12 32, and verify modified plastic B1 piston guide piece, part no. 140 277 10 40, is installed.

To avoid excessive force on automatic adjusting B1 piston diaphragm spring, loosen threaded cover of reaction valve Rv1 (or over-load protection switch S65) by approx. 3 turns during automatic adjusting B1 piston installation procedure.
Tightening torque: 70 Nm

Observe critical attention to ensure that automatic adjusting B1 piston return springs are correctly positioned in B1 piston plastic guide piece and are not twisted or positioned crooked.

Note: Install piston in accordance with installation instructions included in Service Information 27/85a, May 1993.

PRODUCTION PHASE-IN:
Brake band piston B1 with automatic release clearance adjustment is installed as of 6/30/92 production in 722.3 and 722.5 automatic transmissions (as of transmission no. 03 746852).

Also refer to Topic 27T93065.





REMEDY:
1. Remove valve body. Carefully disassemble to separate two halves and remove intermediate plate.

Observe extreme cleanliness

2. Reduce bore 9 (Figure 1, illustration inset) of valve body intermediate plate from 1.1 mm down to 0.9 mm.

MODIFICATION TECHNIQUE:
Using two steel balls of approx. 7mm diameter (eg: CIS.E mixture adjusting tower ball bearing). position one ball below and one bait above bore 9 of valve body intermediate plate. By lightly striking upper ball, it is possible to reduce diameter of bore 9 by 0.2 mm. Use 0.9 mm drill bit shank as gauge to verify final bore diameter.

NOTE: This modification procedure may require the assistance of a second person.





3. Install modified valve body spring, part no. 124 993 30 01. for Control valve B1 (38) (oval, Figure 2).

NOTE: Retaining plate (arrow, Figure 2) must be removed while valve body is separated in two halves.

- Removed spring is 24 mm in length.

- Installed spring is 26.5 mm in length and has a modified spring rate.

- Both springs are 0.8 mm wire diameter.

Production Phase In Information:

Figure 3:

4. Check and if necessary adjust B1 release clearance to 1.8 mm 2 mm at 1 Nm preload OR install automatic adjusting B1 piston (Figure 3). part no. 124 270 12 32. and verity modified plastic B1 piston guide piece, part no. 140 277 10 40, is installed.

- Install automatic adjusting B1 piston in accordance with installation instructions included in Service Information 27/85a, May 1993.

- To avoid excessive force on diaphragm spring. (37a), loosen threaded cover (over-load protection switch S65) of reaction valve Rv1 by approx.3 turns during automatic adjusting B1 piston installation procedure.
Tightening torque: 70 Nm

- Observe critical attention to ensure that return springs (35,36,Figure 3)are correctly positioned in B1 piston plastic guide piece are not twisted or positioned crooked.

NOTE:

- Automatic adjusting B1 piston is installed as of 6/92 production in 722.3 and 722.5 transmissions (as of trans. no.03746852).

- To determine if automatic adjusting B1 piston is installed, observe appearance of cover(40,Figure 3).