Live Axle Location

Hi,

Do you have any comments regarding the pros/cons and roll/instant centres for the following 3-link live axle arrangements:

(A). Live axle located by 2 lower trailing arms and a torque arm extending from the differential case to rear of the transmission (as seen on the 1982-2002 Camaro/Firebird cars. Do you know of other cars using this arrangement?)?

(B). Live axle located by 2 lower trailing arms and a T-arm connecting upper differential case to body/chassis (as seen on the 1963-1977 Alfa Romeo tipo 105 cars. Do you know of other cars using this arrangement?)?

Thanks, I appreciate your comments, and I am enjoying your courses!

Regards,

Joe

a/ Opel, Vauxhall, and Isuzu used a very similar arrangement of their J (?) series cars like the Kadett, Chevette (I don't know if the US 'version' used the same setup), and some Gemini and Piazza models, respectively. rather than tying it to the gearbox they had the torque tube front mount a bit further back, with two lower radius rods and a panhard bar. For the most part it works very well, although with bigger engines the tubes were prone to bending or breaking under extreme stress.

b/ That is very similar tot he common American rear suspension with the top links meeting at the top of the axle, with the A-R design it gives better lateral location, but it also means the roll centre is fixed at the point where the linkage attaches to the axle. Lotus used a different application with the Mk1 Lotus Cortina, where it was fitted underneath the axle - I understand there were also problems with the roll centre and, more critical, breakages - but that may have been due to poor choices in strength vs weight...

I expect there are dozens, even hundreds, of other examples.