Pop Top Arm Repair

If you choose to use this information, or information linked to this page, please understand that you do so at your own risk. Consult your Vanagon Bentley. Information here is based mostly on a 1981 Westfalia, but the wear points and assist construction are very likely the same for later model years.

The ends of the pop top push bar are prone to excessive wear. Each end is housed in a pivot point between the upper and lower arms. The end of each upper arm is narrow. Over time, under normal use, the narrow portion eventually cuts into the push bar posing the risk of it cutting through completely. The hole on this part of upper arm also wears as it rubs on the push bar ends. General opinion seems to be that these parts should be inspected and repaired sooner than later.

- Lift Assist Parts Description And Function.

Each lower pop top arm contains a lift assist system; a cable and spring. A recent viewing of ETKA by the author, showed only one set of assist parts. Regardless, assist parts were likely installed in each lower arm at time of manufacture. Each cable has a bolt shaped part on one end and "Z" termination on the other. The "bolt" seats at bottom of spring, cable passes through spring, exits end of lower arm, follows the curve with the "Z" securing to a hole. As the top is lowered, the cables pull on the springs, the springs expand and tension, and some of the tops' weight is effectively "taken off". As the top is raised, the springs contract and relax which helps the user push up and forward on the push bar. A failed cable(s) may not be detected by the owner. They may not know of these parts and/or have grown accustomed to the weight. The pop top is typically closed most of the time leaving the cables and springs under tension. These cables don't last forever. In time, they will fail. If a cable fails while top is lifted or lowered, the weight of the top suddenly increases.

- Strut Assembly Removal: method 1.

With the top down, bind the upper and lower arms together by passing a suitably sized wire or rope through upper hinge then around lower and upper arms. This wire or rope needs to securely bind the arms together. Failure to do so could result in arms suddenly flinging apart with considerable force. If more work room is needed, the top can be resting but not latched. Consult Bentley for fastener removal. Remove fasteners at upper and lower bracket hinges, raise and safely support top high enough to provide L/R movement for strut arm assembly removal, remove assembly.

- Strut assembly removal: method 2. Untested by author.

Determine if strut assembly can be safely removed as one piece. (i.e. temporary support not in the way) If strut assembly can't be removed as one piece, it's possible to disassemble in situ as required.

- To remove as one piece.

Raise top completely. The top is heavy. Support securely with temporary support. Tension in springs is now almost totally released and stop pins at top of lower arms prohibit further movement. Remove fasteners and/or hinges. Remove strut assembly.

- To take apart in situ, then remove.

Before removing fasteners. On one side, if possible, allow arms to fold slightly toward rear. (this tensions spring slightly). Hold push bar steady, remove stop pin at top of lower arm. Release tension by allowing push bar to move forward. With stop pin removed, forward travel of arms is not limited. Remove "Z" end of cable from hole. Remove fasteners. Remove nut/bolt on push bar, tap arms off end of push bar.

With assembly on bench, disassemble as per steps above. Check cable(s) for excessive wear. They do fail. When a cable fails, and user is lowering or raising top, weight of top suddenly increases. Inspect ends of push bar and hole in big end of upper arm for wear. ID of hole in upper arm can be increased to allow a bushing made of bronze or copper to be epoxied in place. Better yet, weld in a steel bushing. Ensure bushing is aligned properly. The bushing acts as a bearing to spread out pressure. Lubricate these parts. The author epoxied a piece of 5/8" bolt into the push bar ends to add support. If end of push bar is excessively worn, a bushing with solid end can be inserted and secured to each end of push bar.

Authors pics/text of repair: picasaweb.google.com/musomuso/PopTopStrutCableAndSpringEtc#
David Beierl's pics/text of repair picasaweb.google.com/dbeierl/VanagonPopTopHingeTroubles#

- Installation of assembly: method 1.

Pop top safely raised and supported to provide L/R movement of strut assembly, position strut assembly, install lower fasteners, compressing upper arm down, remove wire or rope, line up upper hinge (lowering top further may help). Install Phillips screws most of the way in, caulk the carriage bolt heads and top where they mate, install bolts mostly tight, final tighten Phillips then bolts.

- Installation of assembly: method 2. Untested by author.

Arms could be left unfolded and installed with top still fully raised. If not.... Fold arms and bind together as per removal method 1. Lower pop top leaving enough room so assembly can be put into position. Support top properly. Follow remaining steps in installation method 1.

- Possible issues and tips.

Preplan for a safe way to slowly release the arms once strut assembly is removed. They are under a fair amount of tension. Needle nose vice grips carefully applied to carriage bolt heads can assist removal. Clean top and bolt heads where they meet, caulk bolts, install. Open driver side slider window to ease removal of carriage bolts. Pivot pin push nuts may get deformed during removal. If worn or damaged, SAE push nuts can be purchased from a good generic auto parts store. If using method 2, lowering the top down may make strut assembly installation easier. (reverse of method 1) If so, pre plan for some way to safely lower the top. Be aware that you have to bring the arms back together and tie up if installing as per first removal method. If a cable is broken, a possible solution: picasaweb.google.com/musomuso/PopTopStrutCableAndSpringEtc#5505035759536410866