with Bill Johnston
Samurai to YJ Revolver Conversion
Articulation in the rocks can really make a difference, so for years I have run a set of original Revolver shackles from Metal Made Rite (MMR). When I first started running them on the trail I met Curt Hildebrand (the owner of MMR) and he explained how easily the Revolvers could be custom configured to work with strange spring swaps. He showed me how I could swap out the bottom half of the shackle for a wider model for an upgrade to say, a Jeep YJ spring. It took a few years to finally get around to a YJ swap, but remembering Curt's quick demo I decided to try it. One problem... while I had procrastinated, Curt had sold off the design rights to Tera Manufacturing, the makers of popular TeraFlex suspensions. Why would that be a problem? Read on.
Here you can see a side-by-side comparison of the MMR (Suzuki model) Revolver and the TeraFlex (YJ model) Revolver. As you can see they look almost identical (except for the width and logo). The concept is like an inverted drop shackle, but instead of resting on a bump stop on the underside of the bumper, the Revolver is self supporting. Here you can see the obvious difference in width. But there are a few other differences that we noticed as we looked a little closer. Tera made some design improvements we didn't count on. We had planned to just replace the lower half of the bottom section of the Suzuki model with the same portion of the YJ shackle. Taking the shackle apart is as easy as removing the button head cap screw with an allen wrench. Removing the matching end on the Suzuki model should allow a simple swap, right?
Nope. First hint of change is the relocation of the zirk (grease) fitting, then the different thread pitch of the cap screws.
Here is what really slowed me down. The MMR model used a flat ended, threaded down tube. The newer Tera version improved the design by adding a turned down end on the tube that fit into an enlarged opening for the cap screw. This causes less wear on the cap screw and less binding when the cap screw is torqued down. But this made the components different enough so that they were not interchangeable. With the first plan down the tubes (so to speak), the next step was to see how we could make this work with the least amount of machining. The answer was quite simple actually. Look at the photo to the right. You can see that if we cut down the cross tube of the YJ model, we could use the entire bottom half instead of just the shackle mount. Another reason this worked well was the fact Tera redesigned the internal lubrication to include not only the down tube, but by drilling a passage through to the cross tube it keeps the bushings lubed. Nice improvement! Next came reassembly and it was a snap. You can see where the upper half will fit the stock shackle mounts on the Samurai frame. The bottom half is now wide enough to accommodate the 2.5" wide YJ spring. When installed, you can see where the internal lubrication would aid the twisting motion of the shackle when it articulates. At full droop and at full stuff the spring pack will try to twist with the axle, this causes a bind at the shackles. The fact that the down tube twists cancels the binding and causes less wear on the springs. At full stuff the bottom half lays down on the spring. This is not how the component was designed, but then again it wasn't originally designed for this application. At full droop, the tab that was visible (in the pictures above) on the cross bar stops the shackle from opening too wide. This keeps the shackle from inadvertently flipping back on itself and causing a problem. The YJ conversion is now complete. In a past issue, we used the Trail Tough front YJ conversion kit and it went in easily. A bit farther back in time we had replaced the rear springs with a set of CJ rear springs using Trail Toughs CJ/YJ rear conversion brackets. Because the brackets work with both CJ and YJ springs, all that was left was to add a wider set of spring plates, this Revolver hybrid and of course, a set of stock 5 leaf YJ spring packs. At full stuff, both the front and rear tires now bury into the wheel well evenly. The front is a little deceiving because the axle is moved forward quite a bit. But nothing rubs. The departure angle is very respectable, but check out that approach angle! At full droop, The new Revolver hybrid matches the droop-ability of the front YJ drop shackle conversion we did earlier this year using Trail Toughs conversion kit. This allows the rear tire to match the front tire for an even balance.
TeraFlexTera Manufacturing, Inc. 5251 South Commerce Dr. Murray, UT 84107-4711(801) 288-2585 Voice (801) 288-2571 Fax