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TORSION BARS AND CAR HIGHT

Posted: Wed Aug 04, 2010 9:33 pm
by PAULJ
Well the car has been on the road for about 6 months now and it has been mentioned by a number of people that the back is higher than the front. I thought that I may have got the torsion bars mixed up so have taken some measurements off another moggy at work
Other car, from the front of the seal to ground 24.5 cm
from the back of the seal to ground 26 cm
Although not quite level it looks level

My car, front to ground 24cm
back to ground 29cm. Looks like a hot rod
I did have new springs on the back. Do new springs kick up the back end that much and should I bring the front up in line or will it settle ?

Re: TORSION BARS AND CAR HIGHT

Posted: Wed Aug 04, 2010 9:39 pm
by bmcecosse
You could slacken all the fixings for the rear springs - bounce the car up and down - and put a load in the back - and then tighten the fixings. The front can be raised on the T bars very easily - if you feel that will balance the car out.

Re: TORSION BARS AND CAR HIGHT

Posted: Wed Aug 04, 2010 9:53 pm
by PAULJ
How will that lower the back? surely the back height is set by the radios of the springs. Front and rear mounts and Polly bushes all new. What worries me is if I did get the torsion bars mixed up. I didn't take either end off when cleaning and painting so I'm thinking that the front would be even lower if they were wrong

Re: TORSION BARS AND CAR HIGHT

Posted: Wed Aug 04, 2010 10:03 pm
by bmcecosse
It won't lower the back - just balance it up! Try settling the rear springs first. In extremis - you can get lowering kit for the rear suspension - blocks and longer U bolts. Have to say - most are experiencing sagging springs - rather than too high!

Re: TORSION BARS AND CAR HIGHT

Posted: Wed Aug 04, 2010 10:05 pm
by simmitc
Sorry, not quite understanding the "front of seal" / "back of seal" references. What seal? From where are the measurements being taken?

New rear springs will almost certainly raise the car slightly. For the torsion bars, the important thing is to set both at the same height. The datum line is taken through the centre of the fulcrum pin that goes through the eye-bolt. With the car on level ground and normal loading (no people) the distance from ground to datum point should be 10 and 11/16 inches.

Have you got the correct rear springs?

Re: TORSION BARS AND CAR HIGHT

Posted: Wed Aug 04, 2010 10:14 pm
by bmcecosse
I was wondering about the 'seal' too - but decided to press on....... :-?

Re: TORSION BARS AND CAR HIGHT

Posted: Wed Aug 04, 2010 11:57 pm
by mike.perry
Dimensions according to BMC Workshop Manual. All measurements to ground level
Centre of front of torsion bar 10 11/16 in
Centre of rear of torsion bar 10 11/16 in
Rear spring front anchor pin 10 9/16 in
Rear spring rear hanger top pin 15 7/16 in

Note these dimesions are for the Series MM which had different rear springs but provided that you have the normal car 5 leaf rear springs and standard tyres then the measurements should not be far out. As a rough guide you should be able to just put your hand vertically between the top of the tyre and the bottom edge of the front wing

Re: TORSION BARS AND CAR HIGHT

Posted: Thu Aug 05, 2010 2:01 pm
by Kevin
simmitc wrote:Sorry, not quite understanding the "front of seal" / "back of seal" references. What seal? From where are the measurements being taken?
Maybe he means cills ?

Re: TORSION BARS AND CAR HIGHT

Posted: Thu Aug 05, 2010 9:07 pm
by PAULJ
sorry, yes cills :oops: It was late when I posted

Re: TORSION BARS AND CAR HIGHT

Posted: Thu Aug 05, 2010 10:34 pm
by rayofleamington
As a rough guide you should be able to just put your hand vertically between the top of the tyre and the bottom edge of the front wing
With radials, yes 3 or 4 fingers vertical, but with crossplys (which Paul probably hasn't got) about one finger less.

Re: TORSION BARS AND CAR HIGHT

Posted: Fri Aug 06, 2010 8:08 pm
by PAULJ
It has been mentioned via PM that there was a problem with new springs being too flat and that maybe newer ones have been manufactured with too much curve. I will get longer U bolts and lower with blocks. I have 2.7" between the bump stops and the chassis. Has anyone else had the same problem with new springs

Re: TORSION BARS AND CAR HIGHT

Posted: Fri Aug 06, 2010 8:57 pm
by bmcecosse
Well - that IS a lot! Don't be surprised if they settle down quite quickly - and as I suggested earlier - slacken all the bolts/nuts and bounce the car around - then tighten them up with the suspension under load - ie support the car's weight on the axle while doing so!