M/T - Slips Out of 1st Gear

NO.
2

GROUP
43

SECTION

DATE: JUNE 1988

RE:
MANUAL GEARBOXES NEEDLE BEARING, ADJUSTMENT SHIMS

700

THIS BULLETIN APPLIES TO THE U.S. AND CANADA.
REFERENCE: TP30941/1 (English); MANUAL TRANSMISSIONS M46/M47/M47II

In a few cases, excessive side play in the 1st gear bushings may allow the transmission to slip out of first gear. If this situation occurs, we recommend replacing the 1st gear bushing with a needle bearing, and reducing side play by installing shims.





This repair can only be carried out on gearboxes which have a brass ring attached to the rear of 1st/2nd synchronizing hub, and applies to gearboxes with or without a vibration damper. The adjustment shims should be installed beneath the brass ring.

WORK PROCEDURE





A1
Remove mainshaft from gearbox

Remove gearbox.

Gearboxes with vibration damper:

A2
Press off vibration damper





A3
Remove thrust washer (not attached to vibration damper) and 1st gear and synchronizer ring.

Remove snap ring retaining 1st/2nd synchronizing hub.

A4
Check if brass ring (left arrow) is fitted to synchronizing hub.

If not, fit a new synchronizing hub incorporating a brass ring.

REPLACEMENT OF HUB





A5
Press off 1st-2nd synchronizing hub and 2nd gear and synchronizer ring.

Use counterhold 2853

A6
Reinstall 2nd gear





A7
Disassemble synchronizer





A8
Assemble synchronizer

Place hub inside operating sleeve.





A9
Insert sliding keys (1) and spring rings (2)

Lock the sliding keys with spring rings. Both rings should be hooked onto same key. Engage 1st spring ring counter-clockwise. Turn synchronizer over and engage 2nd ring counter-clockwise. (In other words, rings should start in same key and extend in opposite directions.) If spring ring is bent, the free end of the ring must point out (away from hub).





A10
Lubricate mainshaft and install synchronizer

Turn hub so that groove for brass ring is facing 1st gear.

Do not install brass ring at this stage.





A11
Check position of synchronizing ring.

Use 2852 to support shaft. Install snap ring.

REPLACING BUSHING WITH NEEDLE BEARING 1st GEAR





A12
Press off bushing from 1st gear

Use 5242 (rear axle special tool) to support shaft. Press bushing off with 5080

A13
Clean parts





A14
Install brass ring (1), synchronizing ring (2), needle bearing (3), and 1st gear (4).

Engage snap ring.

ADJUSTMENT OF CLEARANCE





A15
Remove thrust washer from rear of 1st gear

NOTE:
Thrust washer is not installed in gearboxes with vibration damper. Use washer, P/N 1220333-7, only to measure clearance. It must be removed before reassembling the gearbox.





A16
Place support 2853 beneath 2nd gear. Mount shaft in a vice (do not tighten vice)

Push firmly down on shaft to press lock ring into hub. Fit thrust washer and press into position. Measure clearance between washer and gear using a feeler gauge. MIN. clearance = 0.10 mm

NOTE:
Clearance should be as near as possible to 0.10 mm.

Example:
Measured clearance = 0.85 mm.
Fit 2 x 0.35 mm adjustment shims.
Clearance = 0.85-0.70 mm = 0.15 mm

Place shims beneath brass ring.

Gearboxes with vibration damper:





A17
Press on vibration damper

Use 5294 (front end special tool), small end facing down, to press damper into position.

A18
Check that washer is in place on shaft

NOTE:
This is especially important if washer has been removed and reinstalled. It should not be possible to turn washer.

A19
Assemble gearbox

NOTE:
Aluminum surfaces should be treated with assembly paste prior to installing bearings and shafts.

Part Number 1161006-0
Aerosol 1161078-9 Tin

NOTE:
Aluminum gearboxes with vibration damper:
Intermediate shaft should have only 0.0-0.05 mm end play. Preload may contribute to stiff gear shifting. Original adjustment shims can be reused.

NOTE:
Original adjustment shims can be reused.

A20
Install gearbox

Fill with oil

A21
Take care not to crossthread drain plugs

Do not overtighten plugs.
Tightening torque: 27-40 N-m (20-30 ft.lbs.). Applies to gearboxes with aluminum or cast iron housing.