Drive Axle - Front GMC Cab & Chassis V3500

AXLE RATIO & IDENTIFICATION

Axle identification tag is attached to right axle tube. Use this information when ordering parts.

DESCRIPTION

The axle used on "K"Series models has a 4WD center disconnect feature which allows shifting in or out of four wheel drive under most conditions while vehicle is in motion. Axle is shifted by a thermal actuator solenoid contained within right axle tube. (Scheme 19)and (Scheme 20).

The right drive axle consists of a solid axle shaft which rides inside of a stationary axle tube. A short stub shaft with a CV joint is bolted to inner axle shaft flange. Left drive axle consists of a flexible drive shaft using an inner tripod joint and outer CV joint. Left axle tripod joint housing bolts to axle carrier drive flange. CV joint/spindle on outer end of drive shaft slips through steering knuckle/hub assembly. (Scheme 18)

The axle uses a conventional ring and pinion gear set to transmit the driving force of engine to the wheels. Gear set transfers driving force at a 90 degree angle from drive shaft to drive shafts.

Axle is produced with 8 1/4" ring gear (used on K10/20 Series) or 9 1/4" ring gear (used on K30 Series), with minor differences between the 2.

Scheme 18

Scheme 19

Scheme 20

Removal & Installation

1. Raise and support vehicle on safety stands. Remove skid plate (if equipped). Remove wheel and tire assembly. Remove stabilizer bar hardware and remove stabilizer bar from lower control arm. DO NOT mix left and right side components if both sides are being removed.
2. Disconnect left inner tie rod from steering relay rod. Insert a long drift through disc rotor vanes to prevent axle from turning. Loosen hub nut and remove nut and washer from end of drive axle. Disconnect drive axle flange bolts retaining inner tripod joint housing to axle carrier output shaft.
3. Pull down on inner end of axle shaft. DO NOT allow axle shaft to hang free. Using suitable puller, or a brass drift, push outboard end of axle shaft out of hub assembly. Remove drive axle from vehicle.
4. To install axle shaft, reverse removal procedure. Torque all bolts and nuts to specifications. See «TORQUE SPECIFICATIONS»(/gmc/cab-chassis-v3500/1987-1991/remont/differentials-drive-axles/#drive-axle-front) table.

Removal

1. Disconnect negative battery cable. Raise and support vehicle on safety stands. Remove skid plate (if equipped). Remove wheel and tire assembly.
2. Remove stabilizer bar hardware and remove stabilizer bar from lower control arm. DO NOT mix left and right side components if both sides are being removed. Disconnect right inner tie rod from steering relay rod.
3. Disconnect stub shaft flange bolts retaining stub axle to drive axle flange. Turn wheel outward to loosen stub shaft from drive axle flange. Push stub shaft toward front of vehicle and wire aside.
4. Disconnect actuator solenoid connector at axle tube. Disconnect indicator light switch connector at axle tube. Remove actuator solenoid and indicator light switch if these components are to be serviced. Place suitable receptacle under drive axle. Remove drain plug and washer and drain lubricant. Remove nuts and washers retaining axle tube to frame.
5. Remove bolts attaching axle tube to axle carrier. Remove axle tube from axle carrier. Ensure that open end of tube is pointed upward.

Installation

1. If internal carrier components have been changed, see reassembly steps 4) through 9) of «RIGHT AXLE TUBE ASSEMBLY»(/gmc/cab-chassis-v3500/1987-1991/remont/differentials-drive-axles/#drive-axle-front) under OVERHAUL. Apply sealant to carrier sealing surface. Install axle tube to carrier housing. Install 6 retaining bolts and torque to 30 ft. lbs. (40 N.m). Connect stub shaft to inner shaft flange and install bolts. Torque bolts to 59 ft. lbs. (80 N.m).
2. Raise axle tube and install frame-to-tube mounting nuts and washers. Torque nuts to 75 ft. lbs. (100 N.m) on K10/20 Series or 110 ft. lbs. (145 N.m) on K30 Series. Install tie rod end to steering relay rod. Torque tie rod nut to 40 ft. lbs (54 N.m). Install stabilizer bar and hardware. Torque all stabilizer hardware except stabilizer bracket to frame nuts to 13 ft. lbs. (18 N.m). Torque stabilizer bracket to frame nuts to 24 ft. lbs. (33 N.m).
3. Reconnect actuator and indicator switch connectors. Install drive axle drain plug and washer. Torque drain plug to 24 ft. lbs. (33 N.m). Remove filler plug and fill drive axle to level of fill plug with SAE 80W-90 GL5 gear lubricant. Torque fill plug to 24 ft. lbs. (33 N.m). To complete installation, reverse removal procedure.

Remove right axle tube and inner axle shaft assembly. See RIGHT AXLE TUBE & INNER SHAFT in this article. Remove shim. Remove pilot bearing using Pilot Bearing Remover (J-34011). Lubricate new pilot bearing with axle grease. Install pilot bearing using Pilot Bearing Installer (J-33842). To complete installation, reverse removal procedure.

1. Disconnect negative battery cable. Raise and support vehicle. Remove wheel and tire assemblies. Remove 6 right stub shaft-to-axle flange bolts. Remove 6 left axle shaft-to-output shaft flange bolts. Wire left axle shaft and right stub shaft aside. Disconnect drive shaft at pinion yoke and wire aside. Remove all wiring from axle assembly. Disconnect vent hose at axle. Remove nuts, washers and bolts securing right axle tube to frame.
2. Remove lower mounting bolt from axle carrier. Disconnect right side inner tie rod from steering relay rod. Remove engine oil filter (if necessary). Support axle assembly using appropriate transmission jack. Remove upper axle carrier mounting bolt.
3. Lower transmission jack and remove axle carrier from vehicle. To install axle carrier, reverse removal procedure. Torque all nuts and bolts to specification. See «TORQUE SPECIFICATIONS»(/gmc/cab-chassis-v3500/1987-1991/remont/differentials-drive-axles/#drive-axle-front) table.

Disassembly

1. Using side cutter pliers, cut dust boot clamps. Pull boot back from CV joint. Using Snap Ring Pliers (J-8059), spread retaining ring ears apart and pull axle shaft out of CV cage. Slide CV dust boot off of axle shaft.
2. Using a brass drift and hammer, gently tap on cage until it's tilted enough to remove the first ball. Repeat procedure to remove the remaining balls. Rotate inner race at a 90 degree angle to cage and remove race.

Cleaning & Inspection

Wash all parts in solvent and dry with compressed air. Inspect all parts for excessive wear and scoring. Inspect splined stub shaft for wear, cracks and twisted splines.

Scheme 21

Reassembly

1. Repack with half of grease provided in dust boot kit. Place the remainder of grease into dust boot after securing small band clamp.
2. Apply a light coat of CV grease on ball grooves of inner race and cage. Install inner race into cage. Pivot cage at a 90 degree angle to center line of outer race, with cage windows aligned with lands of outer race. NOTE: Ensure retaining ring side of inner race faces axle shaft.
3. Install ball bearings one at a time into outer CV joint as cage is tilted and rotated. After balls are installed into cage, pivot cage and inner race into installed position.
4. Position band clamp onto boot and slide boot onto axle shaft. Secure clamp using side cutter pliers. Coat inside lip (large diameter end of seal with CV grease) and slide large band clamp onto dust boot.
5. Install snap ring onto axle shaft and slide CV joint onto axle shaft until snap ring seats in groove. Slide dust boot toward joint until dust boot is in groove in axle shaft. Secure large band clamp. Reverse disassembly procedure to complete reassembly..

1. Using side cutter pliers, cut dust boot band clamps. Pull boot from tripod housing and separate tripod housing from spider assembly. Wrap tape around spider assembly to retain needle bearings.
2. Using snap ring pliers, remove axle shaft retaining ring and separate spider assembly from axle shaft. Note position of counterbore of spider for reassembly purposes. Remove race retaining ring if necessary. Slide dust boot from axle shaft.

Flush grease from tripod housing. Wash all parts in solvent and dry with compressed air. Inspect all parts for excessive wear and scoring. Inspect splined stub shaft for wear, cracks and twisted splines.

Scheme 22

1. Repack housing using half of grease supplied in dust boot kit. Place the remainder of grease into dust boot after securing small band clamp.
2. Position small band clamp to dust boot. Slide boot onto axle shaft. Ensure boot seats into groove on axle shaft and secure clamp using side cutter pliers. Install spacer ring if previously removed. Ensure ring seats into groove properly.
3. Install spider with counterbore facing end of axle shaft. Install snap ring to retain spider assembly. Position large band clamp onto dust boot. Coat inner lip with grease and seat boot into groove on tripod housing. Secure band clamp. Ensure installed length of dust boot is correct. (Scheme 22) Reverse disassembly procedures to complete reassembly.

Place mounting flange of axle tube assembly in a vise. Remove sleeve. (Scheme 19)or (Scheme 20). Remove snap ring, connector and thrust washer. Tap out axle shaft using a soft mallet. Using a screwdriver, pry out deflector and oil seal. Using appropriate puller and slide hammer, remove bearing.

Wash all parts in solvent and dry with compressed air. Inspect all parts for excessive wear and scoring. Inspect splined stub shaft for wear, cracks and twisted splines.

Scheme 23

1. Clean parts in clean solvent. Clean gasket surfaces on axle tube and carrier housing. Lubricate new bearing using axle grease. Using appropriate bearing driver, install bearing into end of axle tube. Coat lip of new seal with grease. Using appropriate installer, install seal.
2. Install deflector and insert axle shaft into axle tube. Install thrust washer, ensuring notch on tube aligns with tabs and notch on washer. (Scheme 23) Use axle grease to hold thrust washer in place.
3. On K10/20 Series, drive connector gear onto end of axle using a plastic hammer. Install snap ring. On K30 Series, install washer and snap ring. Ensure snap ring seats properly in groove. An output shaft shim of proper thickness must be selected if any of the following parts have been changed. If not, go to step 6). Differential Case Carrier Connector (K10/20 Series) Output Shaft Ring and Pinion Inner Shaft Axle Tube Carrier Case Bearings
4. If any of the listed parts have been changed, use grease to hold ORIGINAL shim in place. Assemble axle tube and inner shaft assembly to carrier. Use no sealer at this time. Torque bolts to 30 ft. lbs. (40 N.m).
5. Install dial indicator onto axle tube with dial indicator shaft at right angle to axle output shaft flange. Check axle shaft end play by pushing and pulling in and out on axle shaft. Maximum end play is.001-.020" (.03-.51 mm). If end play is incorrect, select shim as necessary to bring end play within specification. Remove axle tube from carrier.
6. Clean axle tube and carrier case sealing surfaces. Place correct shim onto output shaft. Hold shim in place with axle grease. Slip damper spring onto shift shaft. Slide shift fork onto shift shaft, ensuring damper spring fits into indentation in shift fork.
7. Install clip, ensuring clip seats properly in shift shaft indentation. Install tension spring on shift shaft. Attach shift fork assembly to carrier case. Apply a bead of Loctite (518) or appropriate sealant to axle tube sealing surface. Assemble axle tube to carrier case. Install axle tube-to-carrier bolts and torque to specification.
8. Inspect shift mechanism operation by inserting a drift into shift actuator hole on axle tube. Rotate axle shaft flange while moving the shift mechanism back and forth with drift. Shift mechanism should work smoothly without binding.
9. Apply Loctite (518) or appropriate sealant to threads of solenoid and install solenoid onto axle tube. Repeat procedure with switch assembly.

Scheme 24

Scheme 25

Scheme 26

Scheme 27

Scheme 28

Scheme 29

Scheme 30

Scheme 31

1. Remove axle carrier. See «FRONT AXLE CARRIER ASSEMBLY»(/gmc/cab-chassis-v3500/1987-1991/remont/differentials-drive-axles/#drive-axle-front) under REMOVAL & INSTALLATION. Remove solenoid and indicator switch from right axle tube. Remove tube and inner shaft assembly. See «RIGHT AXLE TUBE & INNER SHAFT»(/gmc/cab-chassis-v3500/1987-1991/remont/differentials-drive-axles/#drive-axle-front) under REMOVAL & INSTALLATION.
2. Remove sleeve, shift shaft, damper spring, shift fork, clip and inner spring. (Scheme 19)or (Scheme 20). Remove shim. Remove output shaft from right side of carrier assembly. Remove left output flange from carrier assembly by prying on one side with a screwdriver while simultaneously tapping outward on other side with a soft faced hammer. (Scheme 24) Remove deflector.
3. Pry out left output flange seal with a screwdriver. Remove left and right output shaft bearings using Bearing Remover (J-29369-1) for K10/20 Series or (J-29369-2) for K30 Series. Remove bolts holding carrier halves together. Tap on lugs provided to separate carrier halves. Pry up on left and right side bearing locks (right side only on K30 Series) and remove differential assembly from carrier. On K30 Series, remove adjuster plug bolt and lock at left half of carrier.
4. Using Sleeve Remover (J-36599), rotate sleeve and push side bearings (right side only on K30 Series) out of bores. (Scheme 25) On K30 Series, remove adjuster plug, bearing and "O" ring from left side of carrier by rotating adjuster plug using Adjuster Plug Remover (J-36615). (Scheme 26)
5. Using Pinion Flange Remover Set (J-8614-01), hold pinion flange stationary and remove pinion nut, flat washer and pinion yoke. (Scheme 27) Remove pinion deflector. Mount left carrier case half in Holding Fixture from Pinion Service Tool Set (J-36598). Remove pinion with shim, inner bearing and spacer as an assembly. (Scheme 28) Remove bearing spacer.
6. Using Pinion Bearing Remover (J-8612-B) for K10/20 Series or (J-36606) for K30 Series, press bearing from pinion. (Scheme 29) Remove shim from pinion. Using Holding Fixture and Pinion Service Tool Set (J-36598), remove seal and outer bearing from left half of carrier. (Scheme 30) Use Adapter Plate (J-36598-6) on K10/20 Series. Remove bearing races using same service tool set.
7. Using Puller (J-22888-D) and Adapter (J-8107-2) for K10/20 Series or (J-36597) for K30 Series, remove side bearings from differential assembly. (Scheme 31) Remove ring gear bolts. Ring gear bolts are left-hand thread. Using a brass drift, drive ring gear from differential case. DO NOT pry ring gear from case. This will damage ring gear and case.
8. Using a punch and hammer, drive out roll pin from differential pinion gear shaft. Remove pinion gear shaft. On K30 Series, a bolt may be used in place of a roll pin. Roll pinion gears and thrust washers out of differential case.
9. Remove side gears and thrust washers, marking side gears and differential case as left and right for reassembly reference. On K30 Series, remove spacer. Using a 6-point socket, remove vent plug. Upper and lower carrier mounting bushings may be replaced using Remover/Installer (J-36616).

Clean all parts in cleaning solvent. Inspect all parts for excessive wear.

1. Lubricate outer pinion and inner bearing races. Install Holding Fixture from Pinion Service Set (J-36598) used during disassembly. Using race installer from kit, press and pull in outer and inner races until races are seated in housing. Lubricate the inner and the outer bearings, then set pinion depth. Refer to «DRIVE PINION DEPTH ADJUSTMENT»(/gmc/cab-chassis-v3500/1987-1991/remont/differentials-drive-axles/#drive-axle-front) .
2. Install proper shim selected during pinion depth adjustment and inner pinion bearing on pinion shaft using Pinion Bearing Installer (J-35512) for K10/20 Series or (J-36614) for K30 Series. Install new collapsible spacer on pinion shaft. Lubricate outer pinion bearing and install bearing and pinion seal into carrier. Insert pinion with inner bearing and spacer into carrier.
3. Install deflector, pinion flange, washer and nut. Install flange holder used when removing flange and hold flange while torquing pinion flange nut. Torque nut until no end play is present. DO NOT torque further.
4. Rotate pinion several times to ensure bearings have been seated. Set final preload to 15-25 INCH lbs. (1.7-2.8 N.m) by torquing pinion nut in small increments. Each tightening increases preload by several INCH pounds.
5. If preload specification is exceeded, pinion must be removed and collapsible spacer replaced. Once preload has been obtained, rotate pinion several times to ensure bearings have seated and recheck preload. Readjust if necessary.
6. Install side gears and thrust washers into differential case. On K30 Series, install side gear spacer on left-hand side. If old side gears are being reinstalled, ensure they are placed in their original locations as marked during disassembly.
7. Position one pinion gear between side gears and rotate gears until pinion gear is directly opposite opening in case. Place remaining pinion gear between side gears, making sure holes in both pinion gears line up. Rotate pinion gears toward opening just enough to allow installation of thrust washers.
8. Install differential pinion gear shaft. Install roll pin through case and into pinion gear shaft. On K30 Series, install pinion gear shaft bolt (if equipped). Install ring gear onto differential assembly. Torque new bolts alternately in progressive steps to 88 ft. lbs. (120 N.m). Ring gear uses left-hand thread bolts.
9. Press side bearings onto differential assembly using Adapter (J-8092) and Side Bearing Installer (J-22761) for K10/20 Series or (J-29710) for K30 Series. Press bearings onto sleeves (and adjuster plug on left side of K30 Series) using Adapter (J-8092) and Bearing Installer (J-36612) for K10/20 Series or (J-36613) for K30 Series.
10. On K30 Series, install new "O" ring to adjuster plug. Using sleeve adjusting wrench used during disassembly, install sleeves into carrier case (except left side on K30 Series). On left side of carrier on K30 Series, install adjuster plug using same adjuster plug wrench used during disassembly.
11. Install side bearing races into carrier using Adapter (J-8092) and Race Installer (J-36603). Place differential assembly into left carrier case half. Turn left sleeve (K10/20 Series) or left adjuster plug (K30 Series) inward until backlash is felt between the ring and pinion.
12. Remove carrier case from holding fixture and attach carrier halves together using 4 bolts. If halves do not make complete contact, back out right sleeve. Install carrier case bolts and torque to 35 ft. lbs. (47 N.m). Set ring gear backlash adjustment to specification. See «RING GEAR BACKLASH ADJUSTMENT»(/gmc/cab-chassis-v3500/1987-1991/remont/differentials-drive-axles/#drive-axle-front) .
13. Bend lock tabs over left (K10/20 Series only) and right sleeves. On K30 Series, install left adjuster plug lock and bolt. Remove 4 bolts holding axle carrier halves together and separate housing halves. Apply Loctite (518) or appropriate sealant to one carrier housing surface.
14. Reconnect axle carrier housing halves. Install 10 attaching bolts and torque to specification. Using appropriate seal installer, install seal into left side of carrier case. Place deflector onto left output shaft and insert into left side of carrier. Drive into place with a soft-faced hammer.
15. Install new pilot bearing into right output shaft using Pilot Bearing Installer (J-33842). Insert right output shaft into right side of carrier. Apply Loctite (518) or appropriate sealant to threads of vent plug. Install vent plug into left side of carrier.
16. Install right axle tube and inner shaft assembly. See «RIGHT AXLE TUBE & INNER SHAFT»(/gmc/cab-chassis-v3500/1987-1991/remont/differentials-drive-axles/#drive-axle-front) under REMOVAL & INSTALLATION.

Scheme 32

1. Lubricate inner and outer pinion bearings liberally with axle lubricant. Hold pinion bearings in position and install Pinion Shim Setting Gauge (J-36601-4) for K10/20 Series or (J-36601-3) for K30 Series. Install Dial Indicator (J-29763) onto gauge. (Scheme 32) With gauge installed, preload inner and outer pinion bearings to 10-15 INCH lbs. (1.0-1.6 N.m) by tightening shim setting gauge mounting bolt while holding end of gauge shaft with a wrench. Rotate shaft several times to ensure bearings have seated. Recheck preload.
2. Push dial indicator downward until needle rotates approximately 3 turns clockwise. Tighten dial indicator in this position. Set button of pinion shim setting gauge on differential bearing bore. NOTE: 4WD front axle drive pinions are nominal or zero, and are not marked. Shim thickness will equal dial indicator gauge reading.
3. Rotate gauge slowly back and forth until dial indicator reads lowest point of bore. Set dial indicator to zero. Repeat rocking action of gauge to verify zero setting.
4. After zero setting is obtained and verified, move gauge button out of differential side bearing bore. Record dial indicator reading. Use a shim that is exactly the same size as indicator reading.
5. Remove dial indicator and gauge from carrier. Position correct shim on drive pinion. Install drive pinion.

Scheme 33

1. Using sleeve adjusting wrench, tighten right adjusting sleeve until no acklash is present, which is approximately 100 ft. lbs. (140 N.m).
2. Using sleeve adjusting wrench (K10/20 Series) or adjuster plug wrench (K30 Series), tighten left adjusting sleeve until no backlash is present, which is approximately 100 ft. lbs. (140 N.m).
3. Mark location of adjusting sleeves or adjuster plug in relation to carrier halves so notches in sleeves or adjuster plug can be counted when turned. Turn right sleeve out 2 notches using sleeve adjusting wrench. Turn left sleeve (K10/20 Series) or adjuster plug (K30 Series) in one notch.
4. Rotate pinion several times to seat bearings. Mount Dial Indicator Base (J-34047-3) in oil filler plug hole on left side of carrier case. Mount Dial Indicator (J-34047) and Adapter (J-8001-1) through oil vent plug hole so that indicator stem is touching a ring gear tooth. (Scheme 33) Use a small button on indicator stem so contact can be made near heel end of tooth angle for accurate backlash reading.
5. Hold pinion stationary while taking backlash readings. Check and record backlash at 3 or 4 points around ring gear. Gear backlash should be.003-.010" (.08-.25 mm), with a preferred measurement of.005-.007 (.13-.18 mm). Backlash should be the same at each point measured within.002" (.05 mm).
6. If backlash is not within specification, equally turn right and left adjusting sleeves as necessary. To increase backlash, turn left sleeve (adjuster plug on K30 Series) in and turn right sleeve out an equal amount. To decrease backlash, turn right sleeve in and turn left sleeve (adjuster plug on K30 Series) out an equal amount. Turning sleeve (or adjuster plug on K30 Series) one notch will change backlash about.003" (.08 mm). DO NOT install/bend sleeve locks at this time.

AXLE ASSEMBLY SPECIFICATIONS

AXLE ASSEMBLY SPECIFICATIONS

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

See also:
• TORQUE SPECIFICATIONS