Transaxle - JB0-JBl Workshop Manual Updates
83renault21E025
MARCH 1983
L42-M42
JB0-JB1 TRANSAXLE Attention: Workshop, Parts Department
WORKSHOP MANUAL UPDATES
Information
This I.S. Note provides service information for the following conditions on JB0-JBl transaxles used in L42-M42 models.
^ GEARBOX NOISY AND/OR JUMPS OUT OF GEAR IN 5TH SPEED OR IS DIFFICULT TO SHIFT INTO 5TH SPEED
^ GEARBOX NOISY IN 2ND SPEED
Filing Instructions
File this I.S. Note behind page 30 of your B.V. JB manual.
GEARBOX NOISY AND/OR JUMPS OUT OF GEAR IN 5TH SPEED OR IS DIFFICULT TO SHIFT INTO 5TH SPEED
The conditions above may be the result of:
1. low lubricant level in gearbox
2. incorrectly adjusted shift rod or rough surface on selector shaft
3. loose 5th speed nut
1. Low lubricant level in JB1 gearboxes can cause noisy operation and/or jumping out of gear in 5th speed. Continued operation of the vehicle with a low lubricant level could result in damage to the 5th speed cluster, idler gear needle collar bearing, and fork pads.
Before attempting repairs on the gearbox itself, make sure the gearbox lubricant level is correct. If lubricant level is low, fill the gearbox to the correct level and road test the vehicle to verify problem correction.
Refer to the gearbox refilling method on page A-13 of the M.R. 240 workshop manual for lubricant refill or lubricant level correction procedures.
CAUTION: It is important that the lubricant refill method outlined in the workshop manual be followed carefully to avoid incorrect (low) lubricant levels. This is especially important because of the larger capacity, longer refilling time, and difficulty in gauging the correct lubricant level on JB0-JB1 gearboxes.
NOTE: Use Technical Information Code 2-115 for the noise condition and 2-245 for the gear jump out condition it a low lubricant level is determined to be the cause of the problem.
2. Difficult shifting into 5th speed on JB1 gearboxes may be caused by an incorrectly adjusted shift rod (refer to I.S. Note 5 for M.R. 240) or by a rough surface on the selector shaft (A). A rough shaft will wear the shaft guide bushings (B) oval-shaped making shifting difficult (see illustration).
If this problem occurs and shift rod adjustment is correct as outlined in I.S. Note 5 for M.R. 240, install the following selector shaft and guide bushings.
NOTE: Use Technical Information Code 2-153 if a rough selector shaft and worn bushings are determined to be the cause of the problem.
PARTS
Descriptionn Quantity Part Number
BUSHING, Selector Shaft Guide 2 77 04 000 179
SHAFT, Selector 1 77 00 679 963
3. The 5th speed nut may work loose on some JB1 gearboxes built prior to gearbox serial number JB1-003 No. 12.460. This can cause hard shifting into 5th speed, gearbox noise, and/or gear jump out in 5th speed.
This condition was corrected in JB1 gearboxes built after the serial number above by bonding the 5th speed sliding hub to the primary shaft and the 5th speed gear to the secondary shaft with Loctite. In addition, the 5th speed gears on both primary and secondary shafts now have helical rather than straight-cut gear teeth for quieter operation and decreased end thrust.
If the 5th speed nut works loose on a JB1 gearbox built prior to the indicated serial number, bond the 5th speed sliding hub to the primary shaft and the 5th speed gear to the secondary shaft with Loctite 271 Sealant/Adhesive or equivalent. Then replace the 5th speed nut and also the sheet metal end cover, if the lubrication spout in the cover has been damaged.
Use Technical Information Code 2-151 if a loose 5th speed nut is found to be the cause of the problem.
GEARBOX NOISY IN 2ND SPEED
The gear tooth helix angle of the 2nd speed gears in some early JB0 and JB1 gearboxes may cause a noticeable gear whine noise in 2nd speed. This occurs only with JB0 gearboxes built prior to gearbox serial number JB0-001 No. 649 and JB1 gearboxes built prior to serial number JB1-003 No. 2092.
The noise can be eliminated by installing the improved 2nd speed gears used in JBO and JB1 gearboxes built after the serial numbers above. The gear tooth helix angle on these gears has been increased for improved mesh and quieter operation.
NOTE: Use Technical Information Code 2-112 if this problem is encountered.
PARTS
Description Quantity Part Number
PRIMARY SHAFT AND CLUSTER GEARS
JB0 1 77 00 714 139
JB1 1 77 00 714 545
GEAR, 2ND SPEED IDLER (Secondary Shaft)
JB0 and JB1 1 77 00 714 136