It's been discussed but I don't think it's happened yet so I'd be tempted to baseline the existing set-up with a full 4 wheel alignment check.
I know caster is not adjustable but it does affect straight line stability so can it be knocked out by hitting a pothole or bouncing up a curb.
Are the back wheels tracking true with the fronts - is something else the alignment check would confirm
Cheers Spike
I agree with this in principle Spike. The issue is a 4 wheel align (as opposed to a free tracking check) is going to be £40-50+. That's both rear beam bushes and nearly, the two front A-arm bushes as well. If I do any work on the car, that alignment is gone anyway.
It's a relative doddle for me to check the tracking with my Dunlops (they do the rears just as well as the fronts, you just have to reverse the obtained readings: toe in is out and vv). It's also a moment's work to straight edge across front wheels towards the rear and rear wheels towards the front. That'll very quickly tell you if the thing's going down the road straight.
The only thing that can affect castor as far as I can see is the angle of the bottom arm relative to a line perpendicular to the centre-line of the car: i.e. if one arm is further forward / back relative to the other. Trouble there is I've measured from tyre edge to sill on each side and that appears to be fine.
As I say, I've just got this niggle about that old E36: it did the same. Felt very unstable, used to hop sideways over sunken manholes etc. The trouble is I can't remember what resolved it, but am pretty certain it turned out to be the rear despite 100% feeling like the front. The odd thing is if it was the rear, it must have been trailing arm bushes but I just can't remember doing them. Trouble is, this was nearly twenty years ago, maybe more!
No, I think I'll try to set the front as close as factory as I can once these pins arrive (e.g. start bang central). There seems to be minimal compliance in the bushes and they feel the same as the other two cars I have here which drive O.K.. Then I'll change the rear bushes and review the alignment all round. I have a camber gauge so will use that. I'll also see if I can't manually measure the castor somehow. Perhaps set the car level, wheels off but weight on the end of the wishbone (running height). Then measure the angle of the strut.
I spend much of my working life measuring and manipulating body shells back to factory tolerances so am quite used to a lot of this stuff and have a number of tools to help with this.
My big problem with using outside help, esp on alignment is that actually, these all singing and dancing machines yield no better results than the old school methods. How many times have you spent money on a posh four wheel alignment only to drive off up the road with the steering wheel off? The last one I had felt very odd. When I got home I cobbled together a welded up hoop to get to the inside of the rims with a nut welded to one end and a pointer on the other. Bolt went in the nut, under the car it went: tracking was still out! Did it myself after that.
Gratuitous pics of the day job, if nothing else because there's nothing happening at the moment and it does illustrate how my day job 'should' help with dealing with an A2. Or so I thought ?
I built the rotating jig first. It's a March '63 3.8 btw. Not my normal thing but the client was a loyal one and I fancied a change from those 911's. Not my own paint, but carried out by my regular chap who does all of my painting.