Slipping in Fourth Gear or No Fourth Gear, DTC P0734 Set (Replace Lower Control Valve Body Channel Plate and Gasket)
| Subject: | Slipping in Fourth Gear or No Fourth Gear, DTC P0734 Set (Replace Lower Control Valve Body Channel Plate and Gasket) |
| Models: | 2000 Cadillac DeVille, Eldorado, Seville |
| 2001 Oldsmobile Aurora |
| with Hydra-Matic 4T80-E (RPO MH1) Automatic Transmission |
This bulletin is being revised to correct the part number for the reverse clutch housing assembly. Please discard Corporate Bulletin Number 01-07-30-005 (Section 7 -- Transmission/Transaxle).
Condition
Some owners may comment on no 4th gear or it slipping in 4th gear. The "Service Engine Soon" lamp may illuminate. A Diagnostic Trouble Code (DTC) P0734 may be set.
Cause
This condition may be caused by a warped lower control valve body channel plate (900) which allows the loss of 4th band fluid apply pressure.
Correction
Using a Tech 2, check and record any DTCs that are set. Inspect the 4th band (523) and the reverse clutch housing (500) for distress. Replace them as necessary. Also replace the lower control valve body channel plate (900) and the lower control valve body spacer plate/gasket assembly (935).
Refer to the appropriate vehicle Service Manual and Transmission Unit Repair Manual for the proper repair procedures.
Parts Information
Part Number | Description | Qty |
|---|---|---|
8684246 | Band, 4th | 1 |
24212654 | Housing, Reverse Clutch | 1 |
24200434 | Plate, Lower Control Valve Assembly, Channel | 1 |
24213957 | Plate and Gasket Assembly, Spacer | 1 |
Parts are currently available from GMSPO.
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation | Description | Labor Time |
|---|---|---|
K7539 | Reverse clutch and/or housing assembly - Repair or replace | Use Published Labor Time |
Add condition for this bulletin only, not to be published in LTG | Lower control valve body channel plate, spacer and gasket assembly and 4th band - replace | 0.6 hr. |
