1、1,Adjust Ring some use selective shims.Most pinion depth shims are between the gear head and the bearing; some fit between the bearing cup and the carrier.,4,Crush Sleeve,The collapsible spacer, commonly called a crush sleeve, fits between the upper bearing and the lower bearing or gear. Tightening

2、the pinion shaft nut collapses the sleeve and increases the preload on the bearings. A new crush sleeve is used when the pinion gear is installed.,Nut Crush Sleeve,5,Checking Preload,The amount of torque required to rotate the pinion gear is being measured using a low-reading torque wrench. If the a

3、mount is too low, the pinion nut will be tightened further to put more preload on the bearings.,Low-reading Torque Wrench,6,Shim Adjustment,A group of shims are placed between a step on the pinion shaft and the bearings. Thinner shims will increase the amount of bearing preload.,Pinion Gear,Pinion P

4、reload Shims,7,Replacing Differential,The differential and ring gear with the carrier bearings has been placed into the carrier with the ring gear contacting the pinion gear. An adjusting shim is being inserted between the left bearing cup and the housing.,Shim,Carrier,Differential Case,8,Carrier Be

5、aring Preload,A shim is being inserted between the right side bearing cup and the housing. The thickness of this (right side) shim and the left side shim will determine carrier bearing preload and back lash. Carrier bearing preload occurs when the shims are thicker than the space.,Shim,9,Checking Ba

6、ck Lash,The dial indicator is set up using a flexible mount. The measuring stylus is against a ring gear tooth. Back lash is read on the dial indicator by rocking the ring gear back and forth while holding the pinion gear stationary.,Dial Indicator,Ring Gear,Flexible Mount,10,Ring Gear Tooth Names,T

7、he heel is the outer end of the ring gear tooth, and the toe is at the inner end. The pinion gear exerts driving pressure on the more vertical convex side of the tooth while the more slanted, concave side is called the coast side.,Heel Toe,Coast Side: Concave,Drive Side: Convex,11,Contact Pattern,Fa

8、ce Flank,Pinion Tooth Contact,Gear Marking Compound,To check gear contact, a thin film of gear marking compound is painted onto the tooth, and the gears are rotated. The rubbing action of the pinion gear should wipe off a contact area that is about one-half the length of the tooth.,12,Marking Compou

9、nd,A very thin coating of gear marking compound is painted onto the ring gear teeth using a small brush. It is recommended to paint both sides of the gear teeth all the way around the gear.,Painted Teeth,Small Paint Brush,13,Running a Pattern,The pattern will be more distinct and realistic as more l

10、oad is placed on the gears. The screwdriver is being used as a brake to retard the ring gear as the pinion gear is being turned. Note that all of the ring gear teeth should be painted to check the contact of all of the ring gear teeth.,Screwdriver,14,A Good Pattern,The drive sides of these teeth sho

11、w a good contact. The pattern is about one-half the length of the tooth and favors the toe. Under load, the tooth will deflect slightly, and the pattern should become centered.,Gear Contact,Marking Compound (yellow),(Photo Courtesy of Sean Boyle),15,Ideal Contact Location,Toe,Heel,Drive Side,Coast S

12、ide,Gear Marking Compound,Pinion Tooth Contact,The contact pattern should be centered vertically and horizontally on the tooth and should not run off the tooth. Some technicians prefer that the pattern be shifted slightly toward the toe. Ideally, the pattern should have sharp edges without any smear

13、ing.,16,Ring & Pinion Gears,The carrier and pinion gear bearings must be adjusted to the proper preload before trying to run a contact pattern and adjusting pinion depth or backlash.,Pinion Bearings,Carrier Bearings,17,Pinion Too Shallow,This pattern which runs off of opposite ends of the tooth show

14、s that the pinion gear needs to be moved toward the ring gear. This will require a different pinion depth shim.,Toe,Heel,Coast Side,Drive Side,18,Thicker Pinion Depth Shim,Thicker Pinion Depth Shim,A thicker pinion depth shim will move the pinion gear downward, deeper into the ring gear. Changing th

15、e shim requires that the carrier be disassembled completely and then reassembled.,19,Pinion Too Deep,This is the opposite problem from Slide 17 with the patterns running off the other ends of the teeth. This pinion gear is too deep and must be moved out of the ring gear a slight amount.,Toe,Heel,Dri

16、ve Side,Coast Side,20,Reduce Pinion Depth Shim,Thinner Pinion Depth Shim,A thinner pinion depth shim will move the pinion gear upward, less deep in the ring gear. Changing the shim requires that the carrier be disassembled completely and then reassembled.,21,Alternate Pinion Depth Shim,Some drive ax

17、les use a removable pinion retainer with depth shims between the retainer and carrier. Pinion depth can be adjusted without disturbing pinion bearing preload.,Carrier,Pinion Retainer,Pinion Depth Shim,Pinion Gear,22,Insufficient Lash,Both patterns are off the toes of the teeth. This tells us that th

18、e ring gear is too close to the pinion gear, and there is not enough back lash.,Toe,Heel,Drive Side,Coast Side,23,Shift Carrier Bearing Shims, Increase Lash,Moving part of the shim pack from the left side to the right side will move the ring gear away from the pinion gear and increase back lash.,Shi

19、m Movement,24,Excess Lash,Toe,Heel,Drive Side,Coast Side,Both patterns are off the heels of the teeth. This tells us that the ring gear is too far away from the pinion gear, and there is too much back lash.,25,Shift Carrier Bearing Shims, Reduce Lash,Moving part of the shim pack from the right side to the left side will move th