WHY DO I WANT 2.5 TON AXLES?

 TOP LOADING DOUBLE REDUCTION DIFFERENTIAL

BY HAVING THE CENTER SECTION (DIFF ASSY) DROP IN FROM THE TOP OF THE AXLE HOUSING INSTEAD OF THE FRONT OR REAR LIKE CONVENTIONAL AXLES, THIS ALLOWS A FEW POSITIVE THINGS TO HAPPEN; 1) THE DRIVE LINE ANGLES CAN BE REDUCED AS DRIVE PINION IS LOCATED AT THE VERY TOP OF THE DIFFERENTIAL, THIS ALSO HELPS KEEP VULNERABLE DRIVE LINE COMPONENTS OUT OF THE WAY OF TRAIL OBSTACLES, AND LESS LIKELY TO BE SUBMERSED IN MUD OR WATER. IT ALSO ALLOWS A PINION MOUNTED BRAKE SYSTEM TO BE USED WITHOUT THE RISK OF IT BEING DAMAGED. ALSO WITH THE DIFFERENTIAL BEING DOUBLE REDUCTION AND TOP LOADING THERE ISN'T A LARGE CROWN GEAR HANGING DOWN BELOW THE AXLES CENTER LINE, WITH THE PROPER SHAVE KIT, THE GROUND CLEARANCE UNDER A 2.5 TON PAN CAN BE COMPARABLE TO A DANA 44.


FULLY SEALED STEERING AND AXLE COMPONENTS

THE 2.5 TON AXLES RUN A BOOT THAT SEALS TO THE AXLE TUBE AND THE OUTSIDE OF THE STEERING KNUCKLE. IF PROPERLY MAINTAINED, THESE BOOTS WILL COMPLETELY SEAL OUT MUD, WATER AND DUST FROM THE KINGPINS AND AXLE SHAFT U JOINTS, IT ALSO PREVENTS CONTAMINATION FROM EVER ENTERING THE WHEEL BEARINGS THROUGH THE BACKSIDE OF THE SPINDLE.

 

EXCEPTIONAL AFTERMARKET SUPPORT

THE 2.5 TON AXLES HAVE BEEN USED FOR YEARS IN OFF-ROAD GROUPS, FROM ROCK CRAWLING TO MUD BOGGING. BECAUSE OF THEIR POPULARITY, A LOT OF AFTERMARKET COMPANIES HAVE BUILT PARTS FROM DISC BRAKE KITS ALL THE WAY TO MASSIVE CRO-MOLLY AXLE SHAFT KITS. THINGS LIKE TRUSS KITS ARMOR AND BRACKETS ARE ALSO VERY EASY TO PURCHASE.

 

EASY TO WORK ON THE 2.5 TON AXLES

DON'T REQUIRE MUCH FOR SPECIALTY TOOLS TO BE SERVICED, FIELD JOBS LIKE CHANGING AXLE SHAFTS, BEARINGS OR SEALS CAN ALL BE DONE WITH SIMPLE HAND TOOLS. CENTER CHUNKS CAN BE A BIT MORE COMPLICATED TO WORK ON, BUT SELDOM REQUIRE REPAIR. ALSO THE SQUARE PLATE STEEL AXLE HOUSINGS ARE EASY TO WELD TO AND BUILD BRACKETS AND MOUNTS FOR.

 

HOW BIG OF TIRES CAN I RUN WITH 2.5 TON ROCKWELL’S?

THERE ARE MANY VARIABLES TO TAKE INTO CONSIDERATION WHEN DEALING WITH THIS QUESTION, VEHICLE WEIGHT, HORSEPOWER, DRIVING STYLE, AND TERRAIN, ARE ALL THINGS THAT CAN MAKE A DIFFERENCE WHEN TAKING INTO ACCOUNT THE MANNER IN WHICH AXLE WILL HOLD UP. A GOOD RULE OF THUMB IS ANY FULL SIZE TRUCK UNDER 500HP WITH AN AGGRESSIVE DRIVER BEHIND THE WHEEL SHOULD HOLD UP TO 44" TIRES WITHOUT TOO MANY ISSUES. KEEP IN MIND THIS IS NOT A GUARANTEE, NOR DOES IT MEAN THAT A 44" TIRE IS THE LARGEST YOU CAN RUN ON A STOCK 2.5 TON AXLE. THERE ARE MANY PEOPLE RUNNING 50" + TIRES ON HEAVY RIGS WITH DECENT HP THAT HAVE VERY FEW ISSUES, HOWEVER A CONSERVATIVE DRIVING STYLE IS TAKEN INTO ACCOUNT.

 

CAN I JUMP MY RIG WITH 2.5 TON AXLES?

YES, BUT TO A POINT. THERE ARE FACTORY PIECES ON THE 2.5 TON AXLES THAT DON'T LIKE TO BE JUMPED, THE FACTORY KNUCKLES AND SPINDLE STUDS ARE USUALLY THE FIRST PART TO BREAK. KNUCKLES CAN BE PLATED OR REPLACED WITH CUSTOM PLATE STEEL KNUCKLES, SPINDLE STUDS CAN BE REPLACED WITH STRONGER L9 OR EQUIVALENT BOLTS. AFTER THE KNUCKLES AND STUDS ARE ADDRESSED, THE NEXT WEAK POINT MOVES ONTO THE HOUSINGS THAT CAN BEND AND THE KINGPINS THAT CAN SHEAR OFF, AXLE TRUSS AND KING PIN GIRDLES ARE AVAILABLE.

 

DO I NEED TO RUN BOOTS ON MY ROCKWELL AXLES? EVEN IF I AM IN DRY CONDITIONS OR IF I RUN SEALED U JOINTS?

YES, THE ROCKWELL AXLES ARE DESIGNED TO USE KNUCKLE BOOTS, THEY PREVENT DUST, DIRT, AND WATER FROM ENTERING CRITICAL WEAR POINTS LIKE THE KING PIN BUSHINGS, THRUST SURFACES ON THE AXLE SHAFTS, U–JOINTS, ALSO THE ROCKWELL AXLES DON'T USE A SEAL INSIDE THE SPINDLE, WITHOUT THE BOOTS IT IS POSSIBLE FOR CONTAMINATION TO ENTER THE HUB THROUGH THE INSIDE OF THE SPINDLE DOWN THE STUB SHAFT. IT IS HIGHLY RECOMMENDED TO RUN ONE PIECE SILICONE BOOTS AND KEEP THEM IN GOOD CONDITION. IT WILL HELP TO SIGNIFICANTLY CUT DOWN ON MAINTENANCE COSTS.


2.5 TON DIFFERENCES AND SIMILARITY 

SINCE DAY 1, THE 2.5 TON AXLES HAVE ALL BEEN VERY SIMLIAR, THEY ALL USED THE SAME 6.72 RATIO, THE ONLY REAL DIFFERNCE TO BE FOUND, IS IN THE FRONT AXLE SHAFTS. 3 VERSIONS WERE AVAILABLE FROM THE FACTORY; THE BURFIELD BENDIX STYLE, ALSO KNOW AS THE BALL AND CLAW, USES 2 CLAW SHAPED YOKES WITH 5 STEEL BALLS. THE RZEPPA STYLE, THAT RESEMBLES A CV STYLE YOKE. THE U-JOINT STYLE IS THE MOST DESIRABLE, AS THE PIVIOT POINT (THE U-JOINT) IS REPLACEABLE, WHERES THE OTHER 2 STYLES REQUIRE A COMPLETE REPLACEMENT OF THE YOKE IF IT WEARS OUT.

MANY OF THE PARTS ALSO INTERCHANGE BETWEEN THE FRONT AND REAR AXLE, BOTH THE CENTER CHUNK AND THE WHEEL HUBS ARE IDENTICAL FOR THE FRONT AND REAR AXLE. THIS INCLUDES HUB BEARINGS, SEALS, SPINDLE HARDWARE, WHEEL STUDS AND LUG NUTS.

  

FLIPPING THE HUBS

THE HUBS ON A 2.5 TON AXLE CAN ALSO BE FLIPPED TO CHANGE YOUR TRACK WIDTH. THE HUBS USE THE SAME BEARING RACE ON THE INNER AND OUTER BEARING, ALL THAT’S REQUIRED ON THE REAR, IS TO PRESS THE WHEEL STUDS OUT AND FLIP THEM THE OPPOSITE DIRECTION. DURING ASSEMBLY, THE HUB BEARINGS STAY IN THE SAME SPOT ON THE SPINDLE. THE FRONT DOES REQUIRE A SLIGHT BIT MORE WORK, AFTER THE STUDS HAVE BEEN PRESSED OUT AND REINSTALLED YOU WILL ALSO NEED TO SHAVE A SLIGHT BIT OFF THE BACK OF THE STUD TO CLEAR THE SPINDLE BOLT HEAD. THE FACTORY SPINDLE STUDS WILL ALSO NEED TO BE REMOVED AND HEX HEAD BOLTS INSTALLED, KEEP IN MIND THIS MODIFICATION WILL NOT WORK ON THE FRONT AXLE IF YOU ARE RUNNING THE FACTORY DRUM BRAKES.


CHANGING THE CONFIGURATION OF A FRONT STEER AXLE

THE SIMILARITY IN PARTS ALLOWS A FRONT 2.5 TON STEER AXLE TO BE CONFIGURED MANY DIFFERENT WAYS. FROM THE FACTORY, A 2.5 TON HAS THE STEERING TIE ROD BEHIND THE AXLE AND THE CENTER CHUNK ON THE PASSENGER SIDE OF THE VEHICLE, HOWEVER THE AXLE CAN BE FLIPPED AROUND, IF YOU WANT THE STEERING ON THE FRONT OF THE AXLE. SIMPLY REMOVE THE KNUCKLES AND SWAP THE LH SIDE TO THE RH, JUST KEEP IN MIND THIS WILL AFFECT THE ACKERMAN OF THE STEERING. IF YOU WANT TO SWAP THE CENTER CHUNK TO THE DRIVERS SIDE YOU CAN SIMPLY INSTALL THE AXLE OPPOSITE OF HOW IT WAS DESIGNED TO GO IN FROM THE FACTORY, THIS WILL END UP WITH THE STEERIGN OUT FRONT AND THE CHUNK ON THE DRIVERS SIDE. IF YOU WANT THE STEERING BEHIND THE AXLE, SIMPLY SWAP THE KNUCKLES LH TO RH. ANOTHER MODIFICATION THAT CAN BE DONE TO THE 2.5 TON FRONT AXLE, IS THE CHUNK CAN BE FLIPED 180. THIS MOVES THE PINION TO THE CENTER OF THE AXLE IMPROVING DRIVE LINE ANGLES IN SOME CIRCUMSTANCES, YOU CAN WATCH A VIDEO SHOWING HOW ITS DONE HERE.

 

2.5 TON WEIGHTS AND DIMENSIONS

  • 2.5 TON ROCKWELL FRONT 100% COMPLETE 842 LBS
  • 2.5 TON ROCKWELL FRONT NO BRAKES 682 LBS
  • 2.5 TON ROCKWELL FRONT NO BRAKES NARROWED 668 LBS
  • 2.5 TON ROCKWELL REAR 100% COMPLETE 692 LBS
  • 2.5 TON ROCKWELL REAR NO BRAKES 532 LBS

2.5 TON ROCKWELLS CAN HAVE THE HUBS FLIPPED OUT FOR A 79” WMS, OR FLIPPED IN FOR A 69” WMS (69” WMS IS VERY SIMILAR TO 1 TON AXLES)  

WCR CAN ALSO SHORTEN THE LONG SIDE AXLE TUBE, THIS WILL CENTER THE CHUNK AND NARROW THE WMS TO 72” (HUBS OUT) AND 62” (HUBS IN). DURING THIS PROCESS, THE AXLE HOUSING IS STRIPPED, ACID WASHED, THEN PREPPED AND HELD IN A JIG BEFORE AND AFTER WELDING ENSURING THE HOUSING STAYS PERFECTLY STRAIGHT  

WHEEL BOLT PATTERN: 6X8.75  

AXLE SHAFT DIAMETER IS 1-5/8” WITH A COARSE 16 SPLINE