| Check your Lower A arm ball joints [message #321969] |
Sat, 12 August 2017 14:06  |
Larry
Messages: 2875
Registered: January 2004
Location: Menomonie, WI
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The Greater Midwest Classics had a "work" rally at Steve Rasmussen's place last weekend. As one the workers, I was charged with checking the lower A arm ball joints of every coach that was put on either of the two racks. Not necessarily checking for a bad joint, but rather checking for replacement ball joints that were improperly installed or loose. The original ball joints were riveted in place, and according to the manual, (GMC Motorhome Maintenance Manual X-7725) on page 3A-17 under "Ball Joint Checks", a pry bar is used to check for play. The "reading must not exceed .125". That is 1/8th inch. Unfortunately most alignment shops will check for play and to them any play at all is unacceptable, so they charge you for, and replace ball joints that don't need replacement. Consequently there are many coaches out there with new lower ball joints that have been replaced using the grade 8...5/16" bolts that come in the package. These new ball joints are held in place with three bolts. One larger bolt that goes down from the top through the A frame into the ball joint. In addition then, there are two 5/16", bolts on the "Ears" of the joint. Considering that these joints are really replacement for the Toronado or Eldorado, the 5/16" bolts are inadequate for this application. Over time these bolts come loose and can lead to lower arm failure in cracks that can appear around the larger bolt hole or can loosen to the point of falling out, which can eventually lead to a cocking of the joint which changes the camber and can wear out tires in a hurry. If you have replacement joints, the top larger bolt should be checked first for tightness. Then the 5/16" bolts should come out and be replaced with 3/8" X 1 1/4" grade 8 international fine button bolts and you should apply several drops of red Lock Tight to the threads. When drilling out the hole for the larger bolts, use progressively larger drills or reams, until the bolt has a lightly snug fit in the hole. Of the 15 coaches that I checked, EVERY ONE of the lower arm ball joints were loose, and in several cases, bolts on the ears were missing. Even two of the four ear bolts on mine were loose, and I had the 3/8" bolts in place, but without the Lock Tight.
With that kind of a record, everyone should be checking the the bolts on their lower ball joints NOW. JMHO and HTH someone.
Larry 
78 Royale w/500 Caddy
Menomonie, WI.
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