Suspension Fabrication

[fkennette]

I'm in the planning process of making some suspension spares for my 97 Swift (UK) FF1600. The suspension is all aero tube, 1.349x.571x.049", except the pushrods/toe links. I'm considereing making these aero tube as well, but am concerned about strength required on the pushrods, and the slightly less adjustability if using aero-tube versus round tube.

Have noticed in the past that some cars have a few plug/rosette welds along the surface of the aero-tube pushrods, leading me to believe that there is a round tube inside of the aero tube providing additional strength. Can anybody shed any light on this? Is a slightly larger aero tube required for the pushrods? Current pushrods are a set of 7/8" OD w/ .065" wall, and a spare that is 3/4" (wall unknown).

The toe links are 5/8" OD currently, and obviously are infinitely adjustable thru the required range. If I use aero-tube, I'm restricted to a minimum adjustment of 1/2 thread (ie. .021" per 1/2 turn of 5/16-24 rod end). Is this sufficient, or do I need to build in a LH/RH bushing at one end to improve range of adjustability?

Current suspension doesn't have anti-intrusion bars, I'm planning on doing the upper front wishbones only w/ 5/8" OD x .050" wall on the outside w/ 1/2" OD x .062 wall inside. Thoughts?

Any comments or shared experiences would be appreciated, building jigs and ordering tube soon.

Thanks
Francis Kennette
Belle River, ON

[RobLav]

Streamline tubing pushrods and toe links should have turnbuckles with left / right threads to provide infinite adjustability. The issue, especially with pushrods, is that the welding must be precise so that everything is straight. Any angularity will cause bending, stress, and possible fracture.

Check out the chassis shop for parts. (Do a google search...)

I've thought about making these using a 5/8" or 3/4" right hand thread bolt with the head cut off, welded inside the streamline tubing. Then making a turnbuckle out of round 4130 with left and right hand threads at opposite ends - with a left hand thread rodend.

[John Robinson II]

Francis, the pushrods on my db-6 are made out of aero tube. If the lengths are close then you do not need the turn buckles to adjust, as the cars did not come with that originally. Having said that, I have had new pushrods made that incorporate a VD style adjuster, that will allow for the small length adjustments. If you run a car that has drop limiters built in to the shocks, the adjusters are necessary to get the corners spot-on. You might want to get ahold of Ray Germaine @ Protech Eng or Pat prince and they can advise on the wall thickness. I was even considering going to round tubing for the pushrods to avoid the adjusters. Still might.

John