WE USE SUPER RING SUPER-DIFFS ON OUR HIGH PERFORMANCE SWING AXLE TRANSAXLES. THE SNAP RINGS ARE ALMOST TWICE AS THICK AS THE STOCK ONES, VIRTUALLY ELIMINATING SNAP RING FAILURE. THE ADVANTAGE OF THESE DIFFS OVER THE THREADED TYPE IS THAT IT IS RELATIVELY EASY TO PERFORM A FIELD REPAIR. IF YOU BREAK AN AXLE OR SIDE GEAR IN THE DESERT, YOU SIMPLY NEED TO REMOVE ONE AXLE TUBE, REMOVE THE SNAP RING, AND REPLACE THE BROKEN PARTS AS REQUIRED. WITH A THREADED DIFF YOU HAVE TO REMOVE BOTH TUBES, BOTH SIDE COVERS, AND REMOVE AND DISSASSEMBLE THE ENTIRE DIFFERENTIAL ASSEMBLY TO PERFORM SUCH A REPAIR. THIS IS A DIFFICULT, IMPRACTICAL, AND SOMETIMES IMPOSSIBLE REPAIR TO PERFORM IN THE SAND.WE HAVE THREADED DIFFS FOR THOSE WHO INSIST ON USING THEM, BUT WE HAVE NEVER EXPERIENCED A FAILURE OF THE SUPER RINGS, EVEN WITH THE HIGH STRENGTH DEMANDS OF CLASS 9 RACING.

VENTILATION

VENTILATION IS A VERY IMPORTANT AND OFTEN OVERLOOKED PROBLEM IN HIGH PERFORMANCE APPLICATIONS. ALL OF OUR STANDARD HIGH PERFORMANCE TYPE I TRANSAXLES NOW COME WITH A BRASS BARB FITTING INSTALLED IN THE NOSE CONE. A 1/4" HOSE CAN BE ATTACHED TO THIS FITTING AND RUN TO A FILTER PLACED IN A REMOTE LOCATION AWAY FROM SAND AND WATER. WE THEN BLOCK THE TINY STOCK VENT HOLE TO PREVENT OIL LEAKAGE AND TO KEEP SAND AND WATER OUT OF THE TRANSAXLE. THIS MODIFICATION VASTLY INCREASES THE SIZE OF THE VENTILATION HOLE. THIS IS IMPORTANT, BECAUSE ALTHOUGH VW ENGINEERS PROVIDED ADEQUATE VENTILATION FOR A STOCK APPLICATION (53 HP ENGINE RUNNING AT AROUND 3000RPM), THIS IS NOT ENOUGH FOR A HIGH PERFORMANCE APPLICATION. THE PURPOSE OF VENTILATION IS TO ALLOW FOR AIR PRESSURE CHANGES DUE TO TEMPERATURE AND HUMIDITY AND, MORE IMPORTANTLY, TO RELEASE THE PRESSURE CAUSED BY WINDAGE (THE AIR PRESSURE CREATED BY SPINNING GEARS AND SHAFTS). MANY HIGH PERFORMANCE VW ENGINES ARE CAPABLE OF SUSTAINING SPEEDS OF TWICE THAT OF A STOCK ENGINE OR MORE. BECAUSE OF THIS AND BECAUSE OF THE LOW RATIOS USED IN HIGH PERFORMANCE APPLICATIONS, THE STOCK VENT HOLE CAN'T POSSIBLY VENT ALL OF THE WINDAGE PRESSURE. THIS CAUSES A POSITIVE PRESSURE IN THE CASE, INHIBITING OIL FLOW AND SPLASH. WITH THE INCREASED USE OF HIGHER PERFORMANCE ENGINES WE ARE SEEING MORE LUBRICATION FAILURES THAN EVER BEFORE, EVEN WITH THE USE OF THE BEST SYNTHETIC OILS. SINCE WE INSTITUTED VENTILATION IMPROVEMENTS WE HAVE NOTICED THAT THIS PROBLEM HAS ALL BUT DISAPPEARED IN OUR UNITS. ON 002 AND 091 UNITS THE PROBLEM IS MORE NOTICEABLE WITH THE USE OF HIGH RPM ACURA, MAZDA, TOYOTA, PINTOS OTHER EXOTIC ENGINES . FOR THE BUS UNITS WE HAVE DEVISED A MORE COMPREHENSIVE SYSTEM. WE DRILL TWO 1/4" HOLES IN THE GEAR CARRIER, ONE UP HIGH FOR VENTILATION AND ONE LOWER FOR OIL RETURN. (THE BUS CARRIER HAS NO FACTORY HOLES FOR THIS PURPOSE AS THE TYPE I DOES. ALL THE PRESSURE HAS TO PASS THROUGH THE BEARINGS). WE THEN INSTALL A FITTING IN THE NOSE CONE AS WE DO FOR THE TYPE I AND ANOTHER ONE ABOVE THE DIFFERENTIAL PORTION OF THE CASE. WE THEN TEE THE TWO FITTINGS TOGETHER AND LEAVE A 1/4" HOSE FITTING TO BE RUN TO A REMOTE FILTER. THIS HAS PROVEN VERY EFFECTIVE IN SOLVING OIL STARVATION PROBLEMS AT THE 4TH GEAR THRUST WASHER AND MAINSHAFT BEARING.

THE HEAVY DUTY ALUMINUM SIDE COVERS WE USE ON OUR STANDARD HIGH PERFORMANCE UNITS ARE 50% THICKER AND HEAVIER THAN THE STOCK MAGNESIUM COVERS. HEAVIER DUTY COVERS THAN THESE ARE AVAILABLE FOR EXTREME DUTY APPLICATIONS. HEAVY DUTY COVERS ARE NECESSARY BECAUSE OF THE THRUST INHERENT IN HELICAL GEAR SETS. IN OTHER WORDS, THE PINION IS TRYING TO PUSH THE RING GEAR AND DIFFERENTIAL OUT THE SIDE OF THE CASE WHEN YOU ACCELERATE. WITH THE HIGHER HORSEPOWER ENGINES AND LIGHTENED FLYWHEELS, THIS PROBLEM BECOMES MORE PRONOUNCED. THE STOCK COVER WILL FLEX OUTWARD UPON ACCELERATION AND RELAX BACK INWARD ON DECELERATION, CAUSING A BANGING OF THE RING GEAR AGAINST THE PINION. A STIFFER COVER HELPS TO PREVENT THIS FLEX, EXTENDING RING AND PINION LIFE.

YOU MIGHT BE WONDERING WHY YOU NEED HARDENED KEYS AND WELDED 3RD & 4TH GEAR HUBS. ON TYPE I TRANSAXLES THE 3-4 CLUTCH HUB (ABOVE LEFT) IS SECURED TO THE MAINSHAFT WITH A SOFT STEEL WOODRUFF KEY. ON EARLY 4.37'S THE 4TH DRIVE GEAR IS ALSO SECURED TO THE PINION IN THIS MANNER. THESE KEYS WILL SHEAR RIGHT OFF IN HIGH HORSEPOWER (1835cc OR LARGER ENGINES)APPLICATIONS. USE OF HARDENED KEYS PREVENTS THIS PROBLEM.

 THE 3RD & 4TH GEAR SYNCHRO HUBS (ABOVE RIGHT) ARE SECURED TO THE GEARS BY A LIGHT PRESS FIT. THIS IS SUFFICIENT FOR STOCK APPLICATION, BUT WITH INCREASED HORSEPOWER THEY TWIST RIGHT OFF OF THE GEARS. FOR HIGH PERFORMANCE USE IT IS NECESSARY TO WELD THE HUBS TO THE GEARS. THEN THE GEARS MUST BE SURFACED AND HONED TO RESTORE THEM TO ORIGINAL DIMENSIONS CHANGED BY THE HEAT OF WELDING. TO BE FAIR TO OUR COMPETITORS, ANY GOOD TRANSAXLE BUILDER DOES THESE THINGS. WE JUST WANT YOU TO UNDERSTAND WHAT YOU ARE PAYING FOR.

 THIS TECHNICAL SECTION IS INTENDED TO PRESENT YOU WITH AN OVERVIEW OF THE BASIC MODIFICATIONS THAT WE PERFORM ON HIGH PERFORMANCE TRANSAXLES. THERE ARE COUNTLESS OTHER IMPROVEMENTS THAT WE CAN MAKE TO A VW TRANSAXLE, SUCH AS BILLET CHROMOLY IRS DIFF COVERS, ALUMINUM AXLE FLANGES, STEEL AXLE FLANGE STIFFENERS, HEAVY DUTY AXLES, MID-ENGINE AXLE TUBE END CASTINGS, CHROMOLY AXLE TUBES, AND MUCH, MUCH MORE. PLEASE FEEL FREE TO CALL OR CHECK OUR PARTS AND ACCESSORIES PAGE. WE ARE CURRENTLY IN THE EARLY R & D STAGES OF A REVOLUTIONARY NEW MID-ENGINE SHIFTING SYSTEM. LOOK FOR IT ON OUR PARTS AND ACCESSORIES PAGE AFTER WE COMPLETE THOROUGH PROTOTYPE TESTING AND SECURE PATENTS.

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