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Lower control arm caution notice '73 & '74 [message #349419]

Fri, 18 October 2019 18:02

Matt Colie

Messages: 8547
Registered: March 2007
Location: S.E. Michigan

Karma: 7

Senior Member

This is a notice of caution to all owners of early TZEs.

Even thought our lower control arms were reinforced per the factory directive, the right side failed at about 170k miles. This happened on an interstate and at highway speed. I have been able to repair the coach, but it was not a simple operation.

Even if the control arm was reinforced, the factory directive is not adequate in the long term. The control arm failed across the ball joint center bolt hole. Evidence is that both the "ears" were secure right up to the failure. One was still attached to the arm but the other is not visible, so loose fasteners were not the issue. The attachment of both of said ears show signs of metal fatigue that is visible on the recovered ball joint.

I do not know the age of this balljoint as it is not the one that I replaced in '08. The carbon copies of the maintenance orders that I have are no longer legible, so I can not supply a true age. I have checked these fasteners at every front end lube including the before departure for Tallahassee, that would be less than 2000 miles prior to failure. I did not inspect this area for possible cracks.

I am working on a complete write-up of the incident, but it is taking more time than I expected.

Be safe

Matt

Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit

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Re: Lower control arm caution notice '73 & '74 [message #349443 is a reply to message #349419]

Sat, 19 October 2019 20:53

midlf

Messages: 2212
Registered: July 2007
Location: SE Wisc. (Palmyra)

Karma: 1

Senior Member

SteveF, botiemad, did a lot of repairs to these lower A-arms. There has been a ton of discussion on this several years ago.

IIRC bottom line is 72-73 lower arms are not suitable for rebuild/reinforcement. JimK's rebuilt lower A-arms are $935 plus $300 core charge. '73 style lower A-arms are not accepted for cores.

Two sets of postings to the photo archive from botiemad.

http://www.gmcmhphotos.com/photos/g5058-lower-control-arm-reinforcements.html

http://www.gmcmhphotos.com/photos/g5018-oddball-page2.html. (See page 2 for control arms)

On my early '74, w/ '73 style arms, I rebuilt per SteveF's information and correspondence.

http://www.gmcmhphotos.com/photos/g5459-front-suspension-rebuild.html

I will be interested to see what Matt's writeup has to say.

Steve Southworth
1974 Glacier TZE064V100150 (for workin on)
1975 Transmode TZE365V100394 (parts & spares)
Palmyra WI

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Re: Lower control arm caution notice '73 & '74 [message #349449 is a reply to message #349443]

Sun, 20 October 2019 09:26

midlf

Messages: 2212
Registered: July 2007
Location: SE Wisc. (Palmyra)

Karma: 1

Senior Member

Forgot to mention. I swapped control arms between my early '74 and my '75 parts coach. As noted the '73 style arms are not rebuildable. The '75's are.

Steve Southworth
1974 Glacier TZE064V100150 (for workin on)
1975 Transmode TZE365V100394 (parts & spares)
Palmyra WI

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