Re: [AMC-List] (50-63 front suspension)

[Keleigh Hardie <ramblinguy@xxxxxxxxxxxx>]

"Take McPherson struts, for instance. There is no control over camber 
changes at all, and the wheel changes camber as it moves up and down in 
a shallow arc, but not much. It's cheaper to produce as a unit and 
install the same way though"

That's where advertising comes in. Back in the Seventies when struts 
were becoming common, many car makers mentioned them in their ads, even 
though they they were inferior to the wishbone suspensions they 
replaced. Since it was new, a lot of folks probably just assumed it was 
better, which is what the ad writers count on...

Keleigh

amc-list-request@xxxxxxx wrote:
> snip
> ------------------------------
>
> Message: 11
> Date: Tue, 23 May 2006 03:44:18 -0000
> From: <francis.swygert@xxxxxxxxxxxxxxxxxx>
> Subject: Re: [AMC-List] my 62 classic project (50-63 front suspension)
> To: <amc-list@xxxxxxxxxxxx>
> Message-ID:
> 	<8B4C911BEBA5E24888E353FF362B9E7702E65F42@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>
> 	
> Content-Type: text/plain;	charset="us-ascii"
>
> Tom Jennings wrote: "People who slag this suspension as generally "no
> good" simply don't know what they are talking about. It's a fine design,
> if a bit old-fashioned, 40+ years later. It's got a lot of fail-safe
> subtleties in it as do more modern cars; it just has too many parts
> (read: labor costs) for modern tastes. "
>
> Just to clarify, that's mainly to many parts/labor costs for PRODUCTION.
> The upper assembly on the old cars consists of two arms with bushings,
> the trunnion itself, trunnion bushings which screw onto the trunnion and
> into the arms, large o-rings that serve as seals for the trunnion
> bushings, a thrust bearing, spring seat tower, bolt to hold the arms
> together, a bumper mount/spacer that goes on that bolt and between the
> arms, and the rubber bumper (that limits downward suspension travel).
> Then this all has to be assembled into one unit. It's not that hard, but
> takes time. For production that can be costly. Repair costs go up when
> someone unfamiliar with the design has to study it and take the time to
> figure it out as they go. 
>
> In contrast, the single arm design has one large A-arm (dies cost more,
> but once made part doesn't cost much more than the two arms) with two
> bushings, the ball joint, and a pivoting spring seat. Costs less to
> manufacture, and less to install. It's a bit easier to repair, but not
> really cheaper assuming you're replacing the ball joints, bushings, and
> spring seat pivot. The trunnion is pretty simple and easy but takes a
> little more time. With the later design taking the pivoting spring seat
> apart and reassembling with a new bushing takes more time than replacing
> the trunnion with all those parts -- at least most of the time. It
> depends on how badly worn the pivot is. 
>
> Production costs drives more changes to cars than real improvements.
> Theoretically efficiencies in production should improve quality due
> mainly to fewer possible mistakes, but that's a fallacy in the real
> world. Take McPherson struts, for instance. There is no control over
> camber changes at all, and the wheel changes camber as it moves up and
> down in a shallow arc, but not much. It's cheaper to produce as a unit
> and install the same way though (a true McPherson strut with integral
> shock/spring/spindle, not the many modifications such as the Mustand and
> Camaro, and some Japanese cars that simply replace the spring and shock
> with a strut, but are multi link suspensions). The old Rambler
> suspension is better in terms of handling and ride once the spring rates
> are tuned to modern conditions. Camber changes occur, but in a
> controlled manner, and the suspension can be adjusted much more, though
> caster is limited in the 50-61 big car design (-63 small cars), a bit
> less limited in the 63-69 design when adjustable strut rods are used. 
>
>
>
>
> ------------------------------
> snip
>   


-- 
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.1.392 / Virus Database: 268.7.0/345 - Release Date: 05/22/06

_______________________________________________
AMC-List mailing list
AMC-List@xxxxxxxxxxxx
http://www.amc-list.com/mailman/listinfo/amc-list

or go to http://www.amc-list.com