M/T - Breather Vent At Firewall Leaks Oil

Classification:
MT93-004

Section:
Manual Transmission

Reference:
TECHNICAL BULLETIN NTB93-136

Models:
1987-93 Truck

Date:
September 21, 1993

TRANSMISSION VENT TUBE LEAKAGE

APPLIED MODELS:
1987-93 Truck (D21) 2WD/4WD with manual transmission

SERVICE INFORMATION

The manual transmission in some of the affected models listed above may leak gear oil from the breather vent at the engine wall. This condition does not require a transmission overhaul to correct. Use the following Parts Information and Service Procedure to repair incident vehicles.

NOTE:
Before performing the Service Procedure, be sure to check the transmission gear oil level -- an overfill condition could also cause this incident. (If vehicle is cold, the fluid level should be about 3/4" below the fill plug threads. When warm, it should be about level with the threads.)

PARTS INFORMATION

Note:
The breather tube kit listed below is the same part used on 2WD vehicles. However, when installed on 4WD vehicles, an additional rubber plug is necessary.

Part Description Part Number

Breather Tube Kit 38594-18W27
Rubber Plug *

* This part should be available at local auto parts or hardware stores.

SERVICE PROCEDURE

1. Raise vehicle on a hoist.





2. Remove the hose between the transmission breather vent and the T-fitting in the existing breather hose. Save one clamp from the removed hose, then discard the hose.

3. Install a 1/4" plug on the T-fitting shown above and secure with the saved hose clamp.

4. Slide a hose clamp over the long breather hose from the kit and attach this breather hose to the transmission breather vent with the hose clamp.





5. Remove the nut from the upper stud (speedometer cable mounting) on transmission tunnel. See illustration for location.

6. Slide the new clip over the end of the new breather hose and route the hose up the fire wall.

7. Attach the clip to the stud and tighten the nut while making sure that the breather hose does not sag at any portion.

8. Lower the vehicle and open the hood.





9. Locate the end of the breather hose and route it between the brake lines as shown.

10. Remove the screw below the existing breather tube on the engine wall (see illustration). Mount the separator canister bracket to the engine wall using the removed screw.

11. Slide a hose clamp over the breather hose and attach the hose to the bottom of the canister with the clamp. Install the canister into the bracket.

12. Remove the screw to the right of the hood hinge. Mount the vent pipe to the engine wall using the removed screw.

13. Cut 3 inches off the short hose in the kit. Install the remaining 7 inch piece between the canister and vent tube using the hose clamps in the kit.

14. After installing this kit in a 4WD truck, the following parts should be left over: ^ tie wrap
^ tap screw ^ Plastic grommet ^ 3 inches of hose.





WARRANTY INFORMATION