Re: [Amc-list] early american front suspension

[Frank Swygert <farna@xxxxxxx>]

Hmm... never thought about the braking forces much! I had 7.7" tires 
(195 mm) and 79 Spirit disc brakes at the time one of mine worked loose. 
One didn't feel quite as tight as the others in the arm, but didn't turn 
or anything. I did stake it at a visible spot with a punch so I could 
easily see if it was turning. After a few months I stopped looking much 
since it never moved. Checked it weekly for 2-3 months though! Two years 
later things changed somehow. It was a rear cap, so the braking forces 
make a bit of sense -- load is taken off the lower rear when braking 
hard, I'd think. I remember well where I was -- driving from my dad's in 
SC to Governor's Island, NY, for two weeks or Search and Rescue training 
at the Coast Guard station there (now closed). I was in Maryland in the 
vicinity of DC in Maryland. Suddenly the steering was hard and funny. I 
gently put on brakes and pulled over. Looked at the tie rod ends first, 
and saw the lower trunnion on the right side didn't look right. Didn't 
take long to see what it was! I stuffed a wrag around it to protect the 
threads a bit and drove off the interstate to a garage -- closest I 
could find (still didn't feel right, and wrag wasn't lasting long!). 
Told them what I was doing, and knew I'd have to order the part from a 
specialty dealer. They cut me a great deal ($100!) for storing the car 
for the two weeks I'd be gone and someone drove me over to a rental car 
dealer. Wish I could remember the shop name! I got the new lower 
trunnion sent to Governor's Island, rented a car to drive back, jacked 
it up and stuck the cap nut on, then drove it home (about eight hours). 
Didn't miss any training time at all (good thing I left on a Friday 
morning for the two day drive -- needed to be there Monday) Tack welded 
that sucker when I got back and looked at it again -- still have 2/3 of 
a brand new lower trunnion (center piece and one cap nut) somewhere 
around here! ---------- Date: Mon, 10 Sep 2007 19:12:15 -0700 From: Tom 
Jennings <tomj@xxxxxxx> On Monday 10 September 2007 18:11:46 you wrote:

> > I agree -- they are not supposed to be under any rotational stress at all.
> > If everything goes well they never will be. But if for some reason
> > vibration, an unseen cracked thread or other metal particle jams it, trash
> > gets in somehow, etc., it COULD start to stick and turn in the arm.
> > Greasing it regularly is cheap insurance, but so are a couple tack welds!
> > It's out of the car, easy to do, and easy to place the tacks so they can be
> > easily ground or struck off (with a cold chisel). Makes it easy to inspect
> > as well. Those threads into the arms are shallow and strip/wear easily. I
> > thought mine were tight, but a couple years after rebuilding a cap nut
> > managed to work off and find it's way onto the highway. I greased mine
> > regularly also. Just a word of warning!
>   

Yeah, I think I'll take your advice and tack them in a place that is easily 
reached and visible from outside. I'll even paint match it, or drill a tiny 
hole or indent to ease ID.

In fact they are under weird twisting forces when braking hard. The "A" pushes 
towards the rear at the bottom, and forward at the top to a lesser degree 
(longer arm above). That could be doing the loosening, and made worse by big, 
and better, tires and big brakes.

-- 
Frank Swygert
Publisher, "American Motors Cars" 
Magazine (AMC)
For all AMC enthusiasts
http://farna.home.att.net/AMC.html
(free download available!)

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