Re: Front lower control arm inner bushing failure

["Dave Swingle <swingle@xxxx>" <swingle@xxxx>]

Hi Knut..

It's a very typical low-end design. Compared to most late-70's 
American cars it's extremely ordinary. Except for the stressed 
swaybar (nobody does that but Lotus!) it looks very much like a Ford 
Pinto. It works exactly as you described.

One key item that many people miss is that the suspension comoponents 
must be torqued at the resting position. Put it all together, but 
don't torque anything until you have the car sitting on the ground 
and have bounced it a few times. If you torque it all up a bad thing 
happens - at full compression (hitting a bump in the road) the 
bushings are twisted twice as far as designed, and they are always 
under stress except when you are cresting a hill. Neither is good for 
long life.

So - the fix you do, assuming you just put OEM bushings back in, and 
installed them correctly won't be any more short-lived than the ones 
you just took out. How miles did they go before failure? It will most 
depend on condition of the roads where you drive. There is a lot of 
stress on those parts, and I find it amazing that they don't cause 
more trouble than they do. On most cars the suspension bushings 
outlast the car, they are typically well over 100,000-mile parts. 

Dave

--- In dmcnews@xxxxxxxxxxxxxxx, "ksgrimsr <knut.s.grimsrud@xxxx>" 
<knut.s.grimsrud@xxxx> wrote:
> The front right lower control arm inner bushing failed on my daily 
> driver yesterday, and I have a couple questions about the setup.
> 
> Let me first describe the nature of the failure -- the inner sleeve 
> of the bushing separated from the vulcanized rubber of the bushing 
> body resulting in the inner portion of the control arm shifting 
> across the captured inner bushing sleeve under stress. ..
......
> 
> How is the lower control arm geometry and bushing setup supposed to 
> work? Is the intent that the vulcanized rubber of the bushing be 
> pliable enough to accommodate the repeated travel of the 
suspension? 
....
Unfortunately, the original setup doesn't look at 
> all to be robust and I'd hate to do all the work to replace the 
> bushings just to have the fix be short-lived.
> 
> Knut