Rear Axle's Control Arms & Rod
20th July 2004
It consists of 2 upper control arms, which are short, mounted on top of the axle on each side of left and right, while 2 lower control arms at the bottom, which are longer and larger also on each side of left and right.
Finally the lateral control rod. Mounted at the rear across left bottom to right top.
Their original functions are to hold the rear axle in place, yet allowing movement where required.
However modification of the vehicle's height, often lower in any case, has caused these engineered items to run 'out-of-spec' and are not in-sync with the chassis / wheels alignment.
Hence modification of their lengths are required to ensure that: -
It is not too long or too short where it is stretching or pushing the propeller shaft in reference to the gearbox output.
That the lower and upper control arms are still pointing or forcing the axle downwards - this is very important to maintain axle's natural heavy-load grip (due to gravity) is directed to the ground and not up. For this, often, custom brackets are made and secured to the original mounting position on the lower part of the axle and new positions are available that allows the lower control arms to point the axle downwards
It is aligning the axle and not have a swayed or biased direction, where both toe appears to be center.
It is aligning the axle between left and right off-set and not protruding the axle one sided to the wheel mud-guard.
It is aiming the axle's input direct - straight to the gearbox output. Not aimed too high or too low.