Suspension Design

(NARRATOR)>> FOUR LINK SUSPENSIONS OFFER PLENTY OF PERFORMANCE AND ARTICULATION, BUT THEY CAN BE A LITTLE INTIMIDATING FOR THE FIRST TIME BUILDER. TODAY ON XTREME OFF ROAD WE TAKE THE MYSTERY OUT OF THE FOUR LINK, HELPING YOU CHOOSE THE BEST DESIGN FOR YOUR RIDE. PLUS A CHASSIS SUBFRAME KIT THAT MAKES FOUR LINKING YOUR TUBE BUGGY A BREEZE, AND OF THE HUNDREDS OF MIG FILLER MATERIALS OUT THERE THESE THREE ARE GREAT CHOICES FOR ANY SHOP.

(IAN)>> IT'S PROBABLY ONE OF THE MOST REQUESTED TOPICS WE'RE ASKED TO COVER HERE IN THE XTREME OFF ROAD SHOP. IT'S HOW TO PROPERLY DESIGN, BUILD, AND PLAN A GOOD FOUR LINK SUSPENSION SYSTEM ON THE BACK OR THE FRONT OF YOUR RIG. NOW THE SETUP THAT WE HAVE ON THE BACK OF OUR BRONCO PROJECT IS PRETTY IN DEPTH, WITH TRAILING ARMS, SWAY BARS, AND AIR BUMPS, BUT THEY DON'T ALWAYS HAVE TO BE THAT COMPLICATED. IT HONESTLY STARTS BY DECIDING WHICH TYPE OF FOUR LINK SYSTEM WOULD WORK BEST ON YOUR RIG. TO LOOK AT THE DIFFERENT TYPES OF LINK SUSPENSIONS THERE ARE OUT THERE I'M GONNA USE THIS REAR AXLE THAT I PULLED OUT OF ANOTHER PROJECT, BUT BEFORE WE START LOOKING AT THAT THE ULTIMATE QUESTION IS ALWAYS ASKED. WHY ARE LEAF SPRINGS STILL POPULAR TODAY IN BOTH OFF ROAD RIGS AND OEM'S? WELL THE SIMPLE ANSWER IS THAT THEY DO A LOT OF JOBS IN JUST ONE PIECE OF EQUIPMENT. A LEAF SPRING NOT ONLY LOCATES THE AXLE UNDERNEATH YOUR TRUCK, BUT IT'S ALSO THE SPRING IN THE SYSTEM. AS THE TIRE AND WHEEL TRAVEL UP AND DOWN THE LEAF SPRING ACTUALLY FLEXES UP AND DOWN, GIVING YOU THE SPRING IN YOUR SUSPENSION. NINE TIMES OUT OF 10 WE'RE REPLACING LEAF SPRINGS WITH A FOUR LINK. SO THIS WAS AN OBVIOUS GOOD PLACE TO START. FIRST STEP IS WE'LL LOSE THESE LEAF SPRINGS AND START LAYING OUT SOME LINKS.

[ saw cutting metal ]

(IAN)>> WOO!

ONE OF THE MOST COMMON TYPES OF LINK SUSPENSION YOU'RE GONNA FIND OUT THERE IS A PARALLEL FOUR LINK. NOW TO GIVE YOU AN IDEA OF WHAT'S GOING ON HERE I'LL DESCRIBE IT. EACH PIECE OF MASKING TAPE REPRESENTS A LINK BAR TRAVELING FROM THE FRAME, WHICH IS THE CCLAMP, DOWN TO THE AXLE. THE UPPER LINK IS ON THE TOP OF THE TUBE, BOTTOM LINK IS ON THE BOTTOM OF THE TUBE. NOW THIS IS THE SAME TYPE OF SUSPENSION THAT YOU'RE GONNA FIND UNDERNEATH A JEEP TJ OR JK FROM THE FACTORY. NOW THE NICE THING ABOUT THE FOUR LINK SUSPENSION IS IT ALLOWS THE AXLE TO TRAVEL UP AND DOWN, PREVENTS ANY AXLE WRAP, AND WHEN THE LINKS ARE PARALLEL WITH THE FRAME, LIKE THIS SYSTEM HERE, THERE'S ROOM IN HERE FOR GAS TANKS AND OTHER ITEMS LIKE THAT. THE PROBLEM IS, IS WE BASICALLY HAVE A PERFECT SQUARE, AND IF YOU KNOW ANYTHING ABOUT PERFECT SQUARES THERE IS NOTHING TO PREVENT THIS AXLE FROM MOVING FROM SIDE TO SIDE UNDERNEATH THE TRUCK. THAT IS WHY WITH THIS TYPE OF LINK SUSPENSION YOU NEED TO ADD A PAN HARD BAR. IT'S GOING TO ATTACH TO THE AXLE, TRAVEL UP AT AN ANGLE, AND ATTACH TO THE FRAME. AS THE SUSPENSION MOVES UP AND DOWN THE PAN HARD BAR ALSO MOVES UP AND DOWN, BUT THERE'S A KEY TO THIS. AS THIS PAN HARD BAR IS MOVING UP AND DOWN IT'S ACTUALLY PUSHING THIS AXLE BACK AND FORTH UNDERNEATH THE TRUCK. NOW THAT IS NOT A BIG DEAL ON A VEHICLE WITH A SMALL AMOUNT OF WHEEL TRAVEL. YOU KNOW, EIGHT TO 10 INCHES, BUT IF YOU'RE TRYING TO BUILD A RIG WITH A LOT OF WHEEL TRAVEL THAT BECOMES AN ISSUE.

WHAT WE'VE BASICALLY CREATED HERE IS CALLED A SINGLE TRIANGULATED FOUR LINK SUSPENSION SYSTEM. WE'VE LEFT THE LOWER LINKS ALONE AND WE'VE MOVED THE UPPER LINKS AT AN ANGLE. THEY'RE STILL COMING OFF THE FRAME BUT THEY'RE MEETING NEAR THE CENTER OF THE AXLE. THIS DOES NOT REQUIRE A PAN HARD BAR BECAUSE EVEN THOUGH WE STILL HAVE A SQUARE WITH OUR LOWER LINKS, THE UPPER LINKS ARE TRIANGULATED IN THAT SQUARE, PREVENT ANY RACKING OR MOVING OF THE AXLE BACK AND FORTH. IT ALLOWS FOR A LARGE AMOUNT OF WHEEL TRAVEL BECAUSE AS THE TIRE AND WHEEL MOVE UP AND DOWN IT'S BASICALLY PIVOTING RIGHT DOWN THE CENTER OF THE VEHICLE. YOU DON'T HAVE TO WORRY ABOUT THE AXLE SWINGING BACK AND FORTH UNDERNEATH THE TRUCK. THE ONLY DOWNFALL TO THIS PARTICULAR TYPE OF SUSPENSION SYSTEM IS A LOT OF VEHICLES HAVE A FUEL TANK MOUNTED RIGHT IN FRONT OF THE AXLE, EITHER ON THE PASSENGER OR THE DRIVER'S SIDE. SO ONE OF THESE UPPER LINKS WILL CONTACT IT AND YOU'LL HAVE TO RELOCATE IT, MAYBE PUT A FUEL CELL IN THE BACK. ON A JEEP TJ OR YJ THAT'S NOT AN ISSUE BECAUSE THE FUEL TANK IS BEHIND THE AXLE. THAT'S WHY THIS IS PROBABLY ONE OF THE MOST POPULAR SUSPENSION SYSTEMS OUT THERE FOR A JEEP WHEN YOU'RE LOOKING TO INCREASE WHEEL TRAVEL OUT BACK. THERE IS ONE OTHER OPTION THAT YOU COULD ALSO DO AND IT'S PRETTY MUCH LIMITED TO TUBE BUGGIES, AND THAT IS A DOUBLE TRIANGULATED FOUR LINK. YOU LEAVE THESE UPPER LINKS AT AN ANGLE. YOU WOULD THEN TAKE THE LOWER LINKS, KICK THEM IN TOWARDS THE CENTER OF THE CHASSIS AT AN ANGLE AS WELL. THIS MAKES FOR A VERY STRONG, VERY STABLE REAR SUSPENSION SYSTEM THAT GIVES YOU LARGE AMOUNTS OF WHEEL TRAVEL. THE REASON YOU NORMALLY ONLY SEE IT ON TUBE BUGGIES IS BECAUSE IT REQUIRES A LOT OF FABRICATION UP UNDERNEATH THE FRAME. IF YOU'RE DEALING WITH A JEEP WITH TWO FRAME RAILS THIS IS THE EASIEST SETUP TO BUILD.

(NARRATOR)>> UP NEXT THE ESSENTIAL MEASUREMENTS YOU NEED TO DESIGN YOUR FOUR LINK.

(IAN)>> TODAY WE'RE TALKING ABOUT FOUR LINK SUSPENSION AND HOW TO DESIGN ONE FOR YOUR RIG. NOW WE'RE GONNA CONCENTRATE ON THIS SINGLE TRIANGULATED FOUR LINK SETUP BECAUSE IT'S GONNA BE ONE OF THE MOST POPULAR ONES OUT THERE. PROBABLY THE BIGGEST BENEFIT TO A CUSTOM FOUR LINK SUSPENSION IS YOU CAN CHANGE EVERYTHING FROM THE MOUNTING POINTS ON THE FRAME, TO THE MOUNTING POINTS ON THE AXLE, TO THE LOCATION OF YOUR UPPER LINK MOUNTS AT THE TOP OF YOUR PUMPKIN, AND EACH ONE OF THOSE CHANGES WILL HAVE AN EFFECT ON HOW THE SUSPENSION REACTS. WE'RE GOING TO LOOK AT THREE KEY MEASUREMENTS IN OUR SUSPENSION LINK SYSTEM. THE VERTICAL SEPARATION OF THE LINK MOUNTING POINTS ON THE FRAME SIDE FOR THE UPPER AND LOWER LINKS, AND THE SAME AT THE AXLE. LINK MOUNT LOCATIONS IN RELATION TO THE AXLE CENTER LINE, AND THE LINK MOUNT LOCATIONS AS THEY RELATE TO THE GROUND, AND FINALLY THE DISTANCE BETWEEN THE LINK MOUNTS WHEN LOOKING FROM ABOVE. THIS WILL EFFECT HOW THE SUSPENSION REACTS, CREATING ANTISQUAT, ROLL CENTER AND INSTANT CENTER, AS WELL AS REAR STEER CALCULATIONS, BUT WHAT DO ALL THOSE TERMS MEAN? WELL IN A LINK TYPE SUSPENSION SYSTEM ANY ROTATIONAL LOAD THAT'S TRAVELING THROUGH THE AXLE IS TURNED INTO A PUSHPULL ACTION ON THE SUSPENSION LINKS. ANTISQUAT REFERS TO THE AMOUNT OF MOVEMENT IN THE SUSPENSION AS YOU ACCELERATE. THE BACK END OF THE CAR WANTS TO SQUAT DOWN. AS YOU DECELERATE, OR BRAKE, ON A FRONT LINK TYPE SUSPENSION THE FRONT END WANTS TO DIVE DOWN. INSTANT CENTER OR ROLL CENTER IS REFERRING TO THE AMOUNT OF BODY ROLL THAT WILL BE TRANSFERRED INTO THE CHASSIS FROM THE LINKS, AND REAR STEER REFERS TO HOW MUCH THE TIRE MOVES FORWARD OR BACKWARD THROUGHOUT THE SUSPENSION TRAVEL. NOW THE BEST WAY TO UNDERSTAND HOW THAT'S EFFECTED BY DIFFERENT LINK PLACEMENTS IS TO MOCK THIS UP IN A REAL WORLD ENVIRONMENT.

WE'LL SET OUR AXLE ON SOME JACK STANDS 20 INCHES OFF THE FLOOR AND ROLL IN SOME 40 INCH TALL TIRES.

A PIECE OF RECTANGULAR STEEL WILL ACT AS A FRAME RAIL, AND WE'LL BUILD SOME SUSPENSION LINKS OUT OF SOME DOM TUBING, AND ATTACH THEM WITH SOME TABS.

[ welder crackling ]

(IAN)>> THEN WE'LL TAKE SOME KEY MEASUREMENTS OF THE LINK MOUNTING POINTS AND PLUG THEM INTO AN ONLINE CALCULATOR THAT YOU CAN DOWNLOAD FOR FREE OFF THE INTERNET. THIS WILL GIVE US OUR SUSPENSION SUMMARY. I'VE MOCKED UP THIS SPECIFIC SINGLE TRIANGULATED FOUR LINK BECAUSE IT'S A PRETTY COMMON DESIGN. THE NUMBERS ON THIS SUSPENSION ARE ALMOST 200 PERCENT ANTISQUAT AND A ROLL CENTER AXIS OF 28 INCHES. NOW THAT ROLL CENTER IS UNDERNEATH OUR VEHICLE'S FRAME RAIL HEIGHT. SO THAT WILL NOT TRANSMIT INTO A LOT OF BODY ROLL, BUT WHAT DOES 200 PERCENT ANTISQUAT ACTUALLY MEAN. ANTISQUAT REFERS TO WHETHER OR NOT THE BACK END OF THE TRUCK IS GOING TO DROP OR RAISE UP ON ACCELERATION. 100 PERCENT ANTISQUAT MEANS IT STAYS PERFECTLY LEVEL. 200 PERCENT ANTISQUAT MEANS WHEN YOU HIT THE GAS THE BACK END OF THIS RIG IS GONNA LIFT UP IN THE AIR. THE SUSPENSION WILL BECOME MORE STIFF. THAT'S A PRETTY HIGH NUMBER, AND TO LOWER IT WE WOULD INCREASE THE VERTICAL SEPARATION OF OUR LINKS AT THE FRAME, EITHER RAISING THE UPPER LINK UP OR LOWERING THE LOWER LINK DOWN. NOW THAT'S WHY I CHOSE THIS PARTICULAR DESIGN. THIS IS WHAT YOU'D SEE UNDERNEATH MOST JEEPS, OR A MINI TRUCK ON THE TRAIL. THE PROBLEM IS, IS THE BODY IS GONNA BE SITTING RIGHT ABOVE THESE LINK MOUNTS, LIMITS THE AMOUNT OF MOVEMENT YOU CAN RAISE THE UPPER LINK UP. ALSO, IF YOU RAISE THE LOWER LINK DOWN, YOU'RE GONNA LIMIT YOUR GROUND CLEARANCE UNDERNEATH. QUITE OFTEN ON A TRAIL TRUCK YOUR HANDS ARE TIED AS TO WHERE THE LINKS CAN BE PLACED. THAT'S WHY WHEN YOU SEE JEEPS OUT ON THE STREET, THEY HIT THE GAS, THEY QUITE OFTEN LIFT UP, BECAUSE THEY'RE LIVING WITH NOT WANTING TO CUT THE TUB UP JUST TO GET BETTER ANTISQUAT NUMBERS, BUT IF YOU'RE BUILDING A TUBE BUGGY THE SKY'S THE LIMIT.

(NARRATOR)>> FOUR LINK TUBE BUGGIES DO OFFER TONS OF ARTICULATION, BUT WHERE DO YOU BEGIN IF YOU'RE BUILDING ONE FROM SCRATCH? WE CAN HELP!

(NARRATOR)>> WELDING TECH IS FUELED BY ESAB, MAKER OF THE ALL NEW REBEL AND OFFICIAL WELDING AND CUTTING SUPPLIER OF XTREME OFF ROAD.

(IAN)>> DURING OUR LAST WELDING TIP WE HAD A LOOK AT SOME SPECIALIZED MIG FILLER MATERIALS FOR STEEL AND STAINLESS STEEL WELDING. NOW IF YOU REMEMBER I SAID THAT THERE WERE LITERALLY HUNDREDS OF SPECIALIZED FILLER MATERIALS AVAILABLE FOR YOUR MIG WELDER. SO TODAY WE'RE GONNA CONTINUE ON THAT TOPIC. WE'RE GONNA TAKE A LOOK AT THREE DIFFERENT TYPES OF FILLER MATERIAL FOR YOUR MIG WELDER THAT YOU SHOULD DEFINITELY CONSIDER KEEPING IN YOUR SHOP. THE FIRST IS ARISTOROD 12.5, A PREMIUM MANGANESE SILICON ALLOY SOLID WIRE WITH AN ER-70-SSIX DESIGNATION. THE ARISTOROD 12.5 IS TREATED TO PROVIDE EXCELLENT ARC START CAPABILITIES, PROVIDE EASY FEEDING, AS WELL AS STABLE ARC CHARACTERISTICS AND LOW LEVELS OF SPATTER. IT'S MAINLY USED IN HIGH END PRODUCTION WELDING. IT DOES PROVIDE EXCELLENT PENETRATION ALONG WITH A VERY GOOD LOOKING WELD. YOU WILL WANT TO CLEAN ANY MILL SCALE OFF YOUR MATERIAL PRIOR TO WELDING. CORE SHIELD 15 IS AN ALL POSITION SELF SHIELDING GENERAL PURPOSE WELDING WIRE. THIS WIRE IS USED WITH NO SHIELDING GAS AS THE FLUX INSIDE THE WIRE BURNS OFF WHILE WELDING TO PROTECT THE MOLTEN PUDDLE. IT'S CLASSIFIED DIFFERENTLY THAN SOLID WIRE. CORE SHIELD IS E-71-T-14. "E" IS A CURRENT CARRYING ELECTRODE, "SEVEN" IS THE STRENGTH, 70,000 POUNDS. "ONE" STANDS FOR ALL POSITIONS, AND "T" IS A TUBULAR ELECTRODE FLUX CORE. "DASH 14" IS THE WELDING DESIGNATION, IN THIS CASE DC NEGATIVE SINGLE PASS ALL POSITIONS. YOU WILL MOST OFTEN USE FLUX CORE WHEN PERFORMING TRAIL REPAIRS, OR IF YOU NEED TO WELD SOMETHING BUT RAN OUT OF GAS. FINALLY WE HAVE DUAL SHIELD SEVEN-10-XM. IT'S CLASSIFIED SIMILARLY TO FLUX CORE WITH AN E-71-TONE, BUT UNLIKE TRADITIONAL FLUX CORE, DUAL SHIELD IS DESIGNED TO BE USED WITH SHIELDING GAS WHEN WELDING. DUAL SHIELD WIRE IS A VERY SPECIALIZED WIRE, AND IF YOU UNDERSTAND THE PRINCIPLE OF HOW IT WORKS, YOU UNDERSTAND WHERE WE'RE GONNA USE IT. YOU HAVE TO REMEMBER, FLUX CORE WIRE WORKS REALLY WELL AT PROVIDING A GOOD, DEEP, PENETRATING WELD BEAD ON A ROOT PASS WHEN DEALING WITH THICK MATERIAL. THEN WE GO AHEAD, CLEAN THE FLUX OFF, AND WELD A COUPLE OF COVER PASSES WITH SOME SOLID WIRE. DUAL SHIELD WIRE KIND OF DOES THAT ALL IN ONE SHOT. IT'S A THICK WIRE, ZEROFOURFIVE, MEANING WE'RE ONLY GONNA USE IT ON THICK MATERIAL. MAYBE THREEEIGHTHS OF AN INCH AND UP. SO WHERE IS THAT? WELL AXLE TUBES OR BRACKETS ONTO AN AXLE TUBE, OR EVEN A KNUCKLE. YOU'LL BE ABLE TO BURN IN THAT THICK MATERIAL IN ONE SHOT BECAUSE OF THE PENETRATING PROPERTIES OF THE FLUX CORE AS WELL AS THE SMOOTH WELD CHARACTERISTICS OF THE GAS SHIELDED PUDDLE. THIS WIRE IS A LOT OF FUN TO WELD WITH. SO GRAB SOME DIFFERENT TYPES OF FILLER MATERIAL FOR YOUR MIG WELDER AND SPEND SOME TIME PRACTICING DIFFERENT TYPES OF JOINTS. THE MORE TIME SPENT WELDING, THE MORE YOU WILL SEE HOW DIFFERENT FILLER MATERIAL REACTS.

(IAN)>> TODAY WE'VE BEEN TALKING ABOUT HOW TO DESIGN A GOOD FOUR LINK SUSPENSION SYSTEM. NOW WE'VE ALREADY LOOK AT ONE SETUP AND THE LIMITATIONS THAT YOU'RE GONNA HIT IF YOU'RE TRYING TO INSTALL FOUR LINKS INTO A VEHICLE WITH AN EXISTING FRAME AND A BODY, AND AS I SAID, WITH A TUBE BUGGY THE SKY IS THE LIMIT, BUT WHAT DO YOU DO? DO YOU BUILD THE CHASSIS AND THEN DETERMINE THE LINK MOUNTS? WELL A BETTER WAY TO DO IT IS TO ACTUALLY FIGURE OUT WHAT THE LINK MOUNT POSITIONS ARE FIRST AND BUILD THE CHASSIS AROUND THEM, BUT THAT SOUNDS NEARLY IMPOSSIBLE. I MEAN YOU'RE LITERALLY STARTING WITH A BLANK FAB TABLE WITH A LINK MOUNT THAT'S GONNA BE SOMEWHERE AROUND HERE, BUT THANKS TO OUR FRIENDS AT GOAT BUILT FIGURING THIS LOCATION OUT IS A LOT EASIER. THEY NOW OFFER A COMPLETE CHASSIS SUBFRAME KIT. IT IS MADE FROM LASER CUT AND CNC BENT THREESIXTEENTHS HIGH STRENGTH STEEL, AND IS A GREAT STARTING POINT FOR A BUGGY BUILD. FULLY KEYED TO MAKE ASSEMBLY EASY, AND HAS FRONT AND REAR UPPER AND LOWER LINK MOUNTS BUILT IN.

THE BELLY PAN IS VERY EASY TO ASSEMBLE AND WILL PROVIDE YOUR BUGGY PROJECT WITH LINK MOUNTS FOR A DOUBLE TRIANGULATED FOUR LINK FRONT AND REAR. EACH SECTION IS KEYED AND SLOTTED FOR EASY ALIGNMENT AND TIGHT WELD JOINTS. SMALL PIECES OF TUBING ENSURE THAT THE INNER AND OUTER STRUCTURE PIECES ARE ALIGNED CORRECTLY DURING ASSEMBLY. WITH OUR SUBFRAME COMPLETELY ASSEMBLED WE NOW HAVE OUR LINK MOUNT LOCATIONS FOR OUR REAR AND FRONT FOUR LINK ALL FIGURED OUT. THE BEST PART IS, IS GOAT BUILT ALSO OFFERS AN ENGINE CRADLE KIT THAT ATTACHES TO THIS SUBFRAME TO MOUNT AN LS ENGINE, AND A TRANSMISSION MOUNT KIT THAT LOCKS INTO THE MIDDLE. SO BASICALLY THE DRIVETRAIN, OR HEART OF YOUR BUGGY, IS ALL TAKEN CARE OF BEFORE YOU BEND A SINGLE TUBE. NOW WHAT KIND OF NUMBERS DO YOU END UP WITH THIS SUSPENSION SETUP? WELL IF I SET THE BELLY HEIGHT AT 26 INCHES, 40 INCH TALL TIRES WITH 116 INCH WHEEL BASE, PRETTY STANDARD FOR A BUGGY, WE ACTUALLY END UP WITH THREE DIFFERENT ANTISQUAT NUMBERS TO CHOOSE FROM BECAUSE I HAVE THREE MOUNTING LOCATIONS FOR OUR UPPER LINK. IF I PUT IT IN THE BOTTOM HOLE I'LL HAVE 140 PERCENT ANTISQUAT. TOP HOLE GIVES ME 40 PERCENT ANTISQUAT AND THE MIDDLE HOLE GIVES ME 90. NOW WHEN WOULD YOU USE EACH ONE? WELL IF YOU'RE DOING ANY SERIOUS HILL CLIMBING YOU WANT MORE ANTISQUAT SO WE'RE GONNA PUT IT IN THE BOTTOM HOLE. IT PREVENTS THE FRONT SUSPENSION FROM UNLOADING EASILY. DOING ANY HIGH SPEED DESERT RIDING? WELL WE'RE GONNA MOVE IT THE TOP HOLE. IT WILL HELP LIGHTEN UP THE FRONT OF THE BUGGY, ALLOW IT TO QUICKLY MANEUVER ROUGH TERRAIN, AND THEN FOR JUST EVERYDAY TRAIL RIDING AND WHEEL YOU COULD STICK IT IN THE MIDDLE AND END UP WITH A VERY PREDICTABLE 90 PERCENT ANTISQUAT, OR FLAT REACTING BUGGY. EITHER WAY, IF YOU'RE PLANNING TO BUILD A TUBE BUGGY, THIS KIT IS THE PERFECT PLACE TO START.

NO MATTER WHAT TYPE OF LINK SUSPENSION YOU ARE BUILDING THERE'S GONNA HAVE TO BE SOME TYPE OF SUSPENSION JOINT AT THE END OF EACH SUSPENSION LINK TO ALLOW THE SUSPENSION TO MOVE. NOW THERE'S MANY DIFFERENT TYPES, AND THERE'S BENEFITS AND DRAWBACKS FOR EACH ONE. ON A STOCK SUSPENSION SYSTEM THEY USE MOSTLY RUBBER TYPE JOINTS. NOW THIS IS A PIECE OF RUBBER WITH A STEEL SLEEVE VULCANIZED TO THE OUTER EDGE AS WELL AS TO THE INSIDE OF IT FOR THE BOLT TO GO THROUGH. THIS IS A STOCK REPLACEMENT JOINT FOR A JEEP TJ UPPER SUSPENSION ARM. THE BENEFIT TO THE RUBBER, WELL IT'S THERE TO REMOVE ANY POSSIBLE VIBRATIONS THAT WOULD HAPPEN IN THE DRIVETRAIN BEFORE THEY CAN BE TRANSMITTED UP INTO THE PASSENGER COMPARTMENT. GREAT FOR A VEHICLE THAT YOU'RE GONNA DRIVE ON THE ROAD EVERY SINGLE DAY. THE DOWNFALL IS THEY DON'T ARTICULATE VERY WELL, AND WHEN YOU TAKE YOUR VEHICLE OFF ROAD AND FORCE THEM TO FLEX THEY TEND TO WEAR OUT PREMATURELY AND THEY ARE NEED TO BE REPLACED. THE OTHER DOWNFALL IS THAT THEY'RE USUALLY FOUND IN SOME TYPE OF FIXED LINK SUSPENSION SYSTEM LIKE THIS JEEP JK ARM. THAT GIVES YOU NO ADJUSTABILITY IN YOUR SUSPENSION AT ALL, AND THAT'S WHY YOU WILL RARELY SEE THIS TYPE OF SETUP IN ANY TYPE OF HIGH QUALITY AFTERMARKET SUSPENSION SYSTEM. MOST AFTERMARKET SUSPENSION COMPANIES NOW USE THIS TYPE OF REBUILDABLE ROD END. IT GIVES YOU ADJUSTMENT IN THE SUSPENSION THANKS TO THE THREADED SHANK, AND IT'S DESIGNED TO ARTICULATE BECAUSE THE STAINLESS STEEL INNER BALL IS HOUR GLASS SHAPED, DESIGNED TO LET THE SUSPENSION MOVE. INSIDE THERE ARE TWO DELRIN SLIDERS THAT IF THEY EVER DO GET WARN OUT YOU CAN DISASSEMBLE THE JOINT AND REPLACE THEM. THOSE DELRIN SLIDERS ARE THERE TO LUBRICATE THE BUSHING AND TO ELIMINATE SOME VIBRATION BEFORE IT CAN GET TRANSMITTED UP INTO THE PASSENGER COMPARTMENT. NOW IF YOU'RE TALKING ABOUT A HARDCORE THROW DOWN TUBE BUGGY WELL YOU'RE DEFINITELY GONNA BE LOOKING AT SOME TYPE OF ROD END OR HEIM JOINT. THEY ARE INCREDIBLY STRONG, MADE OF CHROMOLY STEEL, FULLY ADJUSTABLE, AND HAS A STAINLESS STEEL BALL INSIDE THAT IS LUBRICATED BY A TEFLON LINER. THEY ARE DESIGNED FOR MAXIMUM AMOUNT OF ARTICULATION AND MAXIMUM AMOUNT OF ABUSE. THE DOWNFALL TO THE ROD JOINT IS YOU WILL FEEL ALL THE VIBRATION IN THE SUSPENSION UP INTO THE PASSENGER COMPARTMENT. NOT AN ISSUE FOR A TUBE BUGGY, BUT FOR SOMETHING YOU'RE GONNA DRIVE EVERYDAY THAT CAN BECOME QUITE ANNOYING. SO WHICH JOINT DO YOU CHOOSE? WELL IF YOU'RE DRIVING IT ON THE STREET YOU GO FOR A REBUILDABLE ROD END. IF YOU'RE HITTING HILLS ON THE WEEKEND YOU GO FOR A HARDCORE HEIM JOINT.