Torsion bars and angle of dangle

[FranklinLeicester]

A few weeks ago I decided jack the front of my car up a bit because the lower wishbones appeared to be nearing the horizontal and as far as I remember, they were never identical. Because of this, there was not a lot of space between the wheel and wing. Compared with other cars mine was definitely low at the front. I cranked the adjusters all the way to what difference it made - of course it looked like a trials car with loads of positive camber. I undid most of the adjustment (same number of turns each side)to get it looking sensible BUT there is noticable positive camber on the n/s and a spirit level shows very slight negative on the o/s. The angle of dangle (anhedral) of the lower wishbones is as near identical as I can get by eye and the distance between the elevation of the outer and inner mounting points is also the same at 160mm. The build manual says 150mm at set-up with no load. When jacked up these measurements are 120mm each side. On jacking the car up carefully in the centre of the chassis cross member, the o/s wheel leaves the ground first as if the torsion bar is stiffer on that side. With both wheels well off the ground the n/s gained loads more positive camber but the o/s only has a small ammount. At all times of these tests all 4 of the bumper ends were identical side to side and the chassis height also side to side taken half way down. I guess the car has always suffered from the lop- sidedness but only when I tried to correct the ride height did it become obvious. Also, I have always had more room between the wheel and wing on the o/s than the n/s.I have done about 300 miles since the adjustments and the car behaves perfectly as id did before. The shocks appear to be OK under "bouncing" tests. My conclusion is that the n/s torsion bar is more flexible than the o/s. Anybody come accross this problem before, and what to do about it?

[daniels917]

Re: Torsion bars and angle of dangle

Hi Franklin, i haven't yet played with the front suspension, but i have noticed the +ve camber on the nearside, and near vertical on the offside. so perhaps it is a generic problem. let us know if you can do anything about it. Merv

[lil_red_roadster]

Re: Torsion bars and angle of dangle

That'll probably be the misaligned chassis that several other members have noted (Terry Reed & Hugh Cumming have both posted on this subject). It can be corrected by shimming between the eyebolt & chassis for the "positive" lower-arm, so it achieves the same negative outcome as the other.

I have noted a slight mismatch on mine, but not to the same extent. I have negative camber on both sides but slightly more (like 30mins) on the one side.

If Lee gets around to making his adjustable top arms (see a concurrent post) maybe we can have a group-buy..!

[FranklinLeicester]

Re: Torsion bars and angle of dangle

I researched the the historical topics but didn't pick up on this one. It did cross my mind to "adjust" the eyebolt fixing but really this sounds a bit of a bodge job to me. Wouldn't it pull the torsion bar out of kilter?

[CosworthCabrioLee]

Re: Torsion bars and angle of dangle

Hi All like I said in most the other post the Roadster I have come into contact with have negative camber on them somtimes worse on one side to the other. You can shim it, but if you measure it correctly then you will find the pick up points are not in the same position that is why I cut mint off and went back to basics, and the machined the piviot points pulling the wheels in.

[FranklinLeicester]

Re: Torsion bars and angle of dangle

I've tweaked the offending lower link out about a quarter of an inch and inserted a "u" shaped spacer in the gap.I released the tension in the tie rod first and also loosened the clamp nut on the rear of the radius rod. I didn't have to dismantle the suspension thankfully. This seems to have corrected the fault to a point where nobody would notice . I'll see haw it settles out and in due course make a better shaped spacer (rugger ball shape) to match the original mounting flange. I don't want the MOT man saying "oy oy, what's this gash bit of metal jammed in here for? No what I mean? Merv, if you want to have crack at it,it took about an hour and a half inc. making the spacer. Jez, just for the record, my car is a LWB supplied in 1983. I don't know how that fits in with the others showing this fault. Thanks for your help once again.

[lil_red_roadster]

Re: Torsion bars and angle of dangle

No more of a bodge than the factory did to Moggies...just been browsing the MMOC forum and seems some Minors left the factory with spacers between eyebolt & chassis..!

[stevejgreen]

Re: Torsion bars and angle of dangle

Interesting stuff.
Perhaps our Chairman can publish his findings in Pitstop as it appears to be relevant to many Roadsters and who knows which other models.
That way a greater audience, rather than just the frequent forum users will be made aware of the problem and its solution.
I think tomorrow if there is pleasantish weather I will be out with a tape measure and a spirit level.