Difference between revisions of "Pop Top Arm Repair"

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''Note: this article is still in edit mode. I hope to have it fine tuned soon.''<br>
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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 lift assist construction are very likely the same for later model years.  
  
Given that these parts support a fair amount of weight, use this information at your own risk. Consult your Vanagon Bentley. This repair was done on a 1981 Westfalia.  
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The ends of the pop top push bar are prone to excessive wear. Each push bar end pivots at ends of upper and lower arms. Over time, under normal use, [http://www.vanagonwiki.net/wiki/File:UpperArmAtPushBar.jpg a&nbsp;narrow portion on each upper arm (narrow portion in pic repaired)] eventually [http://www.vanagonwiki.net/wiki/File:PushBarGroove.jpg cuts into the push bar] posing the risk of it cutting through completely. General opinion seems to be that these parts should be inspected and repaired sooner than later.<br>
  
Each end of the pop top push bar is prone to wearing through. The ends are housed at a pivot point between the upper and lower arms. The&nbsp;relatively narrow&nbsp;end of each upper arm eventually cuts into the push bar. There is a risk that it could cut right through. The hole on this part of upper arm also wears as it rubs on the push bar ends. General opinion is that these parts should be inspected and repaired sooner than later.  
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===== - Lift Assist Parts Description And Function. =====
  
Parts description and normal operation.  
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Each pop top lower arm contains a [http://www.vanagonwiki.net/wiki/File:PopTopCablesmall.jpg cable] and [http://www.vanagonwiki.net/wiki/File:PopTopSpring.jpg spring] to provide lift assistance. A recent viewing of ETKA by the author, showed only one set of assist parts but 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 lower arm, follows the curve with the [http://www.vanagonwiki.net/wiki/File:PopTopCableDetails.jpg "Z" securing to a hole]. As top is lowered, the "bolt" end of cables pull on the springs. As the springs compress the tops' weight is effectively reduced. As top is raised, the springs expand pull on the cables, thus helping the user raise the top. A existing failed cable 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.&nbsp;'''If a cable fails while top is being lowered, the weight of the top suddenly increases.'''
  
The author recently viewed version of ETKA that showed the Westfalia as having a lift assist on one side. It's highly likely the factory installed one on each side. The assist system is made up of a cable and spring in each lower arm.&nbsp;The&nbsp;cable has a large bolt shaped part on one end, a "Z" termination on the other, and passes through a spring. The "bolt" seats at bottom of spring, exits lower arm, follows a curve on big end of upper arm with "Z" securing to a hole. As the top is lowered, the cables pull the springs open tensioning the springs. This effectively "takes some weight off" the user. As the top is raised, the springs are allowed to contract which aides in lifting.&nbsp;Some Westfalias may only have one spring working or none at all. Since the pop top typically spends most of it's time,&nbsp;the springs stay expanded, putting the cable and springs under stress.&nbsp;
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===== - Strut Assembly Removal: method 1. =====
  
<span class="Apple-style-span" style="font-size: 16.6667px; ">Strut assembly removal.</span>
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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. Particularly when assembly is out of vehicle. 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.<br>  
  
With top down, resting but not latched, secure upper arm to lower arm at bracket ends with suitable wire or rope. Ensure that wire or rope is passed through upper hinge then around lower arm so it won't slip down the arms. If this happens, the arms will spring apart with considerable force. Remove fasteners at upper hinges. Needle nose vice grips may help hold carriage bolts from turning. Remove pins from lowers. Raise and secure pop top to provide room for strut arm assembly removal.  
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===== - Strut assembly removal: method 2.&nbsp;  =====
  
A possible alternate way to remove strut assembly:<br>Raise top to full height. Prop top safely. Though springs in arms will be almost totally UN-compressed there might be slight tension remaining. Regardless. If stop pins installed correctly, remaining tension should not be an issue. Remove fasteners and/or hinges. If prop not in the way, there may be enough room to take out strut assembly as one piece. If not enough room, one might consider removing the stop pins, then allow lower arm to move up taking tension off cable. Regardless, remove the "Z" end of cable from arm, then take apart one side while all is still in Westy. The author has not tried this.
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''Untested by author. May require clarification. Method offered as alternative to keeping arms folded under tension and may provide insight if one is only replacing a broken cable.&nbsp;''
  
With assembly on bench, "Z" part of cable can be removed from hole with needle nose pliers. If not, remove stop pin, safely let upper arm rotate further, remove "Z". Remove nut &amp; bolt, tap arms off push bar. Check cable(s) for signs of excessive wear. When a cable fails, and user is lowering or raising top, weight of top effectively, and suddenly, increases. Inspect ends of push bar and hold in big end of upper arm for wear. To date, a common repair approach is to install a sleeve in hole at big end of upper arm to act as a bearing and spread out pressure. A bushing made of bronze or copper can be epoxied in place. Better yet, weld in a steel bushing. Lubricate these parts. Though likely not needed, the author epoxied a piece of 5/8" bolt into the push bar ends to add support.  
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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.  
  
Possible issues:<br>Pivot pin push nuts may get deformed during removal. Both sizes of pivot pin and push nut can likely be sourced from a generic auto parts store in SAE size.<br>Strut assembly removed, arms still under tension (still secured to each other): Preplan for a safe and slow way to release the arms once unsecured.  
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===== - To remove as one piece. =====
  
Installation or assembly: pop top safely propped up ~ 1/4 way, work assembly into position, install lower fasteners, slowly release the arms, line up upper hinge (top may need to be lowered for this to line up bolt holes). Install Phillips screws most of the way in, caulk the carriage bolt heads. Install bolts mostly tight, final tighten Phillips then bolts.<br>&nbsp;
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Raise top completely. '''The top is heavy'''. Support securely with temporary support. The springs are now almost totally UN-compressed, so tension is almost gone. Stop pins at top of lower arms prohibit further movement. Remove fasteners and/or hinges. **&nbsp;''If possible, remove lower pins first, then upper pins. Removing arms with upper hinges attached might require the use of a ladder to get at carriage bolt heads. Be aware that installation of upper pins may be difficult due to limited room for push nut installation. It may be possible to install push nut on inward facing side of upper arm.''** Remove strut assembly.
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===== - To take apart in situ, then remove.  =====
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'''Before removing fasteners. '''On one side, remove push nut on [http://www.vanagonwiki.net/wiki/File:PopTopStrutStopPin.jpg stop pin at top of lower arm]. 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 allowing push bar to move forward.&nbsp;'''Caution: with stop pin removed, elbow of arms can now travel further forward. '''Remove lower pivot pin, rotate arm slightly to rear and up, place tape at end of arm (to keep spring in) rotate lower arm up, remove "Z" end of cable from hole. (Taking things apart this far can allow installation of new cable)&nbsp;Remove cross bolt on push bar, tap arms off end of push bar. <br>
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If assembly removed as unit, when on bench, disassemble and check cable(s) for excessive wear. Inspect ends of push bar and hole in big end of upper arm for wear. Repair methods will vary, in part, depending on amount of wear at push bar ends. Regardless of method, installation of a bushing on upper arm is needed&nbsp;to provide a larger bearing surface. Align bushing properly.&nbsp;
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Authors pics/text of repair:&nbsp;[http://picasaweb.google.com/musomuso/PopTopStrutCableAndSpringEtc#5501604219504466738 picasaweb.google.com/musomuso/PopTopStrutCableAndSpringEtc#5501604219504466738]<br>David Beierl's pics/text of repair:&nbsp;[http://picasaweb.google.com/dbeierl/VanagonPopTopHingeTroubles# picasaweb.google.com/dbeierl/VanagonPopTopHingeTroubles#]<br>
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===== - <u></u>Installation of assembly: method 1.  =====
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Pop top safely raised and supported high enough to provide L/R movement of strut assembly, position strut assembly, install lower fasteners, compress upper arm down, remove wire or rope, align 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 screws, then bolts.<br>  
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===== -Installation of assembly: method 2.  =====
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''Untested by author. May require clarification.''
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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.
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===== - Possible issues and tips.  =====
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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. Use locking type nuts on push bar bolts. 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, [http://www.vanagonwiki.net/wiki/File:Pop_Top_Assist_Cable_Mockup.jpg a possible solution].<br>
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[http://www.vanagonwiki.net/wiki/File:File-PopTopCable.jpg This cable] has been installed on both sides. [http://gerry.vanagon.com/cgi-bin/wa.exe?A2=ind1008D&L=vanagon&P=R9109 Notes on manufacturing and installation.]<br>

Latest revision as of 10:24, 26 August 2010

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 lift 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 push bar end pivots at ends of upper and lower arms. Over time, under normal use, a narrow portion on each upper arm (narrow portion in pic repaired) eventually cuts into the push bar posing the risk of it cutting through completely. General opinion seems to be that these parts should be inspected and repaired sooner than later.

- Lift Assist Parts Description And Function.

Each pop top lower arm contains a cable and spring to provide lift assistance. A recent viewing of ETKA by the author, showed only one set of assist parts but 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 lower arm, follows the curve with the "Z" securing to a hole. As top is lowered, the "bolt" end of cables pull on the springs. As the springs compress the tops' weight is effectively reduced. As top is raised, the springs expand pull on the cables, thus helping the user raise the top. A existing failed cable 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 being 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. Particularly when assembly is out of vehicle. 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. May require clarification. Method offered as alternative to keeping arms folded under tension and may provide insight if one is only replacing a broken cable. 

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. The springs are now almost totally UN-compressed, so tension is almost gone. Stop pins at top of lower arms prohibit further movement. Remove fasteners and/or hinges. ** If possible, remove lower pins first, then upper pins. Removing arms with upper hinges attached might require the use of a ladder to get at carriage bolt heads. Be aware that installation of upper pins may be difficult due to limited room for push nut installation. It may be possible to install push nut on inward facing side of upper arm.** Remove strut assembly.

- To take apart in situ, then remove.

Before removing fasteners. On one side, remove push nut on stop pin at top of lower arm. 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 allowing push bar to move forward. Caution: with stop pin removed, elbow of arms can now travel further forward. Remove lower pivot pin, rotate arm slightly to rear and up, place tape at end of arm (to keep spring in) rotate lower arm up, remove "Z" end of cable from hole. (Taking things apart this far can allow installation of new cable) Remove cross bolt on push bar, tap arms off end of push bar.

If assembly removed as unit, when on bench, disassemble and check cable(s) for excessive wear. Inspect ends of push bar and hole in big end of upper arm for wear. Repair methods will vary, in part, depending on amount of wear at push bar ends. Regardless of method, installation of a bushing on upper arm is needed to provide a larger bearing surface. Align bushing properly. 

Authors pics/text of repair: picasaweb.google.com/musomuso/PopTopStrutCableAndSpringEtc#5501604219504466738
David Beierl's pics/text of repair: picasaweb.google.com/dbeierl/VanagonPopTopHingeTroubles#

- Installation of assembly: method 1.

Pop top safely raised and supported high enough to provide L/R movement of strut assembly, position strut assembly, install lower fasteners, compress upper arm down, remove wire or rope, align 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 screws, then bolts.

-Installation of assembly: method 2.

Untested by author. May require clarification.

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. Use locking type nuts on push bar bolts. 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.


This cable has been installed on both sides. Notes on manufacturing and installation.