A/T - Slips/Engine Races When Upshifting From 3rd Gear

9215bmw01

Group 24
Automatic Transmission


Bulletin Number
24 10 91 (3428)


Woodcliff Lake, NJ
November 1991
Product Engineering


SUBJECT: Transmission Valve Body Modification

MODELS: All with 4HP22 EH E7 control system


Customer
Complaint: Transmission slips and engine races when upshifting from third gear. If vehicle is slowed down, power transmission resumes.

Situation: The 1-2/3-4 sequence valve in the transmission valve body is sticking in its bore. If this occurs, instead of releasing the "E" clutch and applying the "F" clutch for 4th gear, now the "B" and "C" clutch are both released when MV1 is energized. The engine races when this occurs as the one-way clutch for first gear is overrunning due to the high road speed. If the vehicle speed is reduced or throttle is applied to induce a 4-3 downshift, power transmission is resumed.

Diagnosis: The following quick check will provide an exact diagnosis of this complaint:

As the engine starts to race, select 3rd gear by either of two methods

- by moving gear selector lever from position D to position 3
- by switching program selector from E to either S or M


If the power transmission is immediately restored by the above actions, it is confirmed that the 1-2/3-4 sequence valve is sticking.


Solution: A repair kit is now available which includes the necessary parts to be exchanged on the transmission valve body.

Parts Included In Repair Kit





1) Housing for MV1 and MV2
2) Sequence valve 1-2/3-4
3) Compression spring
4) Support plate
5) Intermediate plate


Parts To Be Transferred From Old to New Valve Housing

6) Support plate 11) MV1 and MV2
7) Ring 12) Fixing plate
8) Inner compression spring (if used) 13) Cap screw
9) Compression spring 14) Check ball
10) Piston


Absolute cleanliness is a must during the exchange of the valve body parts. Only clean, lint-free rags should be used during this operation.

Torque specifications should be strictly adhered to:

- Valve housing to valve body bolts 5 N-m
- Valve body to transmission 8 N-m
- Oil strainer 8 N-m

Parts
Information: The repair kit is available under the following part number:

Description Part Number

Valve body repair kit 88 88 9 999 422

Warranty
Information: Covered under the terms of the applicable BMW New Car Limited Warranty.

Defect code: 24 33 00 29 00

Description Labor operation Model FRU

R & R valve body 24 30 002 635CSiA 14
R & R valve body 24 30 004 535iA, 735iA 14
Exchange valve housing 24 99 000 535iA, 635CSiA, 735iA 2