Author Topic: MCI 8 front radial arm Bushing Post/Bracket  (Read 1484 times)

Offline chart1

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MCI 8 front radial arm Bushing Post/Bracket
« on: July 03, 2013, 06:50:03 AM »
The front radial arm bushing post/bracket that the bushing goes around is cracked on left and right side where it connects to the bus I have welded it before but the cracks are back. what would be causing these stress cracks?
1976 MCI 8
8v71/740auto
8" roof raise

Offline Nick Badame Refrig/ACC

  • 1989, MCI 102C3, 8V92T, HT740, 06' conversion FMCA# F-27317-S "Wife- 1969 Italian/German Style"
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Re: MCI 8 front radial arm Bushing Post/Bracket
« Reply #1 on: July 03, 2013, 03:57:30 PM »
Hey Chart,

Maybe as simple as a defective casting! ??

How is your alignment? Does it stay straight or pull?

You could call Luke at US Coach and ask if he has crossed this path before!

Good Luck
Nick-
Whatever it takes!-GITIT DONE! 
Commercial Refrigeration- Ice machines- Heating & Air/ Atlantic Custom Coach Inc.
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Offline chart1

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Re: MCI 8 front radial arm Bushing Post/Bracket
« Reply #2 on: July 03, 2013, 04:07:31 PM »
It drives straight.
1976 MCI 8
8v71/740auto
8" roof raise

Offline bevans6

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Re: MCI 8 front radial arm Bushing Post/Bracket
« Reply #3 on: July 04, 2013, 12:25:16 PM »
Does it crack in the weldment itself, or beside the weld?  I just went out and looked at my bus, which is the same, the lower radius arm is basically captured on a tube that extends through the post from side to side.  The uppers I couldn't see clearly.  If it broke it's going to have been simple fatigue, most likely, all front end braking loads go through those posts, as well as some suspension control loads and steering loads, but not much of those two.  If it cracked again, put it down to a faulty weld with insufficient penetration or HAZ control.  It's probably just plain mild steel, from the rust I see on mine.  Once something under cyclic loads cracks it's actually quite hard to repair without replacing so I wouldn't feel bad about your welding  :).  Also - where exactly is your crack located?

Brian
1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
Allison MT-647
Tatamagouche, Nova Scotia

Offline Dave5Cs

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Re: MCI 8 front radial arm Bushing Post/Bracket
« Reply #4 on: July 04, 2013, 04:17:55 PM »
Nope not going there never mind. :o
"Perfect Frequency"1979 MCI MC5Cs 6V-71,644MT Allison.
2001 Jeep Cherokee Sport 60th Anniversary edition.
1998 Jeep TJ ,(Gone)
 Somewhere in the USA fulltiming.

 

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