Timing Procedures: All Models
It is essential that both countershaft assemblies of the front and auxiliary sections are “timed.” This as- sures proper tooth contact is made between main- shaft gears seeking to center on the mainshaft during torque transfer and mating countershaft gears that distribute the load evenly. If not properly timed, serious damage to the transmission is likely to result from unequal tooth contact causing the mainshaft gears to climb out of equilibrium.
Timing is a simple procedure of marking the appro- priate teeth of a gear set prior to installation and placing them in proper mesh while in the transmis- sion. In the front section, it is necessary to time only the drive gear set. And depending on the model, only the low range, deep reduction, or splitter gear set is timed in the auxiliary section.
Marking countershaft drive gear teeth.
Prior to placing each countershaft assembly into case, clearly mark the tooth located directly over the keyway of drive gear as shown. This tooth is stamped with an “O” to aid identification.
TOOTH MARKED ON EACH COUNTERSHAFT DRIVE GEAR FOR TIMING PURPOSES
Marking main drive gear teeth.
Mark any two adjacent teeth on the main drive gear.
Mark the two adjacent teeth located directly opposite the first set marked on the main drive gear. As shown below, there should be an equal number of unmarked gear teeth on each side between the marked sets. B TEETH MARKED ON MAIN DRIVE GEAR FOR TIMING PURPOSES
Meshing marked countershaft drive gear teeth with marked main drive gear teeth. (After placing the mainshaft assembly into case, the countershaft bearings are installed to corn= plete installation of the countershaft assemblies.)
When installing the bearings on left counter; shaft, mesh the marked tooth of countershaft drive gear with either set of two marked teeth on the main drive gear.
Repeat the procedure when installing the bearings on right countershaft, making use of the remaining set of two marked teeth on the main drive gear to time assembly.
C. DRIVE GEAR SET PROPERLY TIMED
Timing the deep reduction gear set of 8-speed “LL” models; the low range gear set of 9-speed models; or the splitter gear set of 13-speed models.
Mark any two adjacent teeth on the mainshaft gear of set to be timed. Then mark the two ad- jacent teeth located directly opposite the first set marked as shown in Illustration B.
Prior to placing each auxiliary countershaft as- sembly into housing, mark the tooth stamped with an “O” on gear to mate with timed main- shaft gear as shown in Illustration A.
Install the mainshaft gear in position on range mainshaft OR output shaft.
Place the auxiliary countershaft assemblies into position and mesh the marked teeth of mating countershaft gears with the marked teeth of mainshaft gear as shown in Illustration
C. 5. Fully seat the rear bearings on each counter- shaft to complete installation.