Cam Tube Service Kit Installation
Hendrickson released guidelines for installing the cam tube service kit on compatible axle/beam weldments.
The cam tube service kit can be installed on compatible suspensions from the inboard side of the wheel. It’s not necessary to remove the hub, tire/wheel assembly or brake drum.
If necessary, remove the brake adjuster from the camshaft and remove the existing cam tube. Using #2EP NLGI chassis lube, lightly lubricate the internal seals and bushings on both ends of the new cam tube assembly.
From the inboard side of the suspension beam, slide the new cam tube assembly into the camshaft through the mounting hole in the suspension beam and into the spider. (See Figure 1.) Make sure the end of the cam tube without the decal goes onto the camshaft first. Rotate the cam tube so the grease fitting is accessible (either pointing downward or to the rear) when the drums are installed.
It’s important not to weld or otherwise fasten the cam tube assembly to the spider. The assembly simply slip fits into the spider, according to the company.
Next, arrange the two cam tube brackets back to back and slide them onto the end of the cam tube assembly. Make sure to slide the cam tube brackets onto the cam tube until they contact the suspension beam.
Rotate the cam tube bracket so its holes align with the holes or slots in the suspension beam. If necessary, rotate the cam tube so the grease fitting is accessible when the drums are installed.
Install the four nuts and bolts and tighten them to 35 ft.-lbs. to 45 ft.-lbs. of torque. Now slide the S-cam journal washer onto the camshaft and seat it against the cam tube assembly.
Using retaining ring pliers, hold open the retaining ring and slide it on the end of the camshaft. Lock the retaining ring into the groove on the camshaft. Slide the second S-cam journal washer onto the camshaft and seat it against the retaining ring.
Lubricate the single, centrally-located grease fitting with approximately 4 oz. of #2EP NLGI chassis lube. Add grease until it purges from the cam tube inboard seal. Wipe away excess grease purged from joints to help prevent contaminants from being attracted to the lube points and grease from getting on the brake linings.
Finally, complete the process by installing the brake adjuster, spline inner washers and spline retaining ring.
Transmission Fluids
Effective December 31, 2006, General Motors Corp. no longer licensed Dexron III automatic transmission fluid. Allison currently is working with the oil and additive industry to develop Dexron VI fluids and also has created a new automatic transmission fluid specification, Schedule 1 TES-389, as a direct replacement for Dextron III fluids.
This new fluid specification provides end users with another choice of transmission fluids along with Castrol TranSynd and Allison specification TES-295.
Dexron VI fluids are not a direct replacement for Dexron III fluids. Seals and O-ring materials used in Allison 1000, 2000, 3000 and 4000 series transmissions are being changed for compatibility with Dexron VI fluids.
Improved Regulator
A revised water temperature regulator has been developed to improve the functionality of the cooling system on Caterpillar C7 model (Serial No. KAL1-99999, SAP1-99999 and WAX1-50709) on-highway engines.
The revised water temperature regulator also improves the heating capabilities in the cab of on-highway trucks.
It also has a reduction in the amount of zinc in the water temperature regulator, which minimizes the chance of corrosion. Corrosion can cause the water temperature regulator to crack.
If your customer is experiencing low heat in the cab, check the operation of the water temperature regulator. Replace the water temperature regulator (Part No. 115-4223) with the same part number.
The new water temperature regulator was effective on August 1, 2006 with serial number WAX50710-Up. SAP1-Up, KAL1-Up and WAX1-50709 on-highway truck engines should replace the old water temperature regulator with the new one for improved heating capabilities and the functionality of the cooling system.
Engine Brake Slave Lash Specification Changed
Effective with the introduction of the Mack 757GB59B and 757GB59C engine brakes, the engine brake slave piston lash specification was changed from .017″ to .021″ for all J-Tech Engine brakes with the newer reset screws (Part No. 4559-032053[A][B]).
According to the company, the .021″ slave lash specification also must be used for engines manufactured prior to the production implementation of the latest J-Tech engine brakes that were field-updated to the newer components.
Improved Rings
An improved top ring has been released for Caterpillar C-15 (Serial No. 9NZ1-Up) and C-15 (Serial No. BXS1-Up, MXS1-Up and NXS1-Up) engines that are used in high load applications.
The improved top piston ring is made from stronger materials. The stronger materials have a proven robustness in order to withstand fatigue from high cycles, according to Caterpillar.
For the stated engines, replace the 237-0194 top piston ring with the 247-6130 top piston ring on the piston prior to assembly. High load applications include coal and logging applications with a gross vehicle weight rating greater than 140,000 lbs.
Bussed Electrical Center
With the introduction of the V-Mac IV system in CXP and CTP models, the new electrical system architecture for Mack vehicles uses a bussed electrical center (BEC) and engine power distribution module (EPDM). When diagnosing an electrical system malfunction, you must use the J 35616-4 purple male test lead adapter on the BEC and EPDM terminals.
Do not use a test light or multimeter probe to perform voltage or continuity tests. Doing so will spread the contacts to the point where they will not grip the fuse or relay terminals tightly enough, resulting in additional electrical problems.
If the contacts are spread apart, you will need to replace the BEC and EPDM units. (See Figure 2.)
If the terminals are spread apart as a result of the use of improper test adapters, replacement of the BEC and EPDM units will not be covered under warranty.
Interference Between Driveline Yoke & Crossmember
In certain applications, the input yoke of the front-rear drive axle may contact the front-of-suspension crossmember on Mack CXU, CXP, CXN and CHN models equipped with either the MaxLite 20/40 or MaxLite 20/40 EZ suspension.
If you encounter this condition, a service replacement crossmember (Part No. 48QL432M10), which provides adequate clearance between the input yoke and the bottom of the crossmember is available, according to the company.
The service replacement crossmember, which is designed to be assembled in chassis, is supplied with body bound bolts, and the center section and end gussets are reamed to fit.
When assembling the crossmember, the center section and end gusset mounting bolts are to be tightened to 138 lb.-ft. Huck-Spin frame fasteners must be used to secure the crossmember to the frame rail. The original length fasteners can be used.
Any air system valves, stand-off brackets, etc., which were mounted on the original crossmember can be remounted to the replacement crossmember in the same positions.
Improved Oil Cooler Core
Caterpillar 3126 (Serial No. 1ED1-Up), 3126B (Serial No. 6PZ1-Up and 7JZ1-Up), 3126E (Serial No. LEF1-Up) and C7 (Serial No. FML1-Up and FMM1-Up) engines contain an improved oil cooler.
Teardrop-shaped spacers and cleats for the center support were added between the cooler plates in order to improve the integrity of the oil cooler.
Copper plating also has been added to the spacer in order to ensure that adequate brazing occurs.
Interruption Of Daytime Running Light Operation
Mack warned that on its CXP and CTP model chassis, it’s possible that operation of the daytime running lights (DRL) could be interrupted by certain CB radio frequencies.
In order to eliminate this problem, the company has developed a revised DRL module (Part No. 116MO39A). Replace the current DRL module with the new part number. (See Figure 4.)
