New Suspension sagging

[MichaelBeckNZ]

Evening all

Around December i install my springs ( No prior sagging so repainted & installed new bushes ) along with my recon'd axle.
Every rubber part has been replaced and new eyebolts installed.

I have noticed the rear RH spring sagging until the bumpstop is only an inch or so from the chassis,

Any suggestions welcomed.

[philthehill]

How old are the springs.?
Have you checked the bodywork around the front and rear spring hangers?
Have you checked the leaf springs for a broken leaf.
After market springs appear to have a poor record going by the posts on here.
The rear springs supplied by JLH appear to have good feedback.
It is not recommended to replace only one spring (except in an emergency). They should be replaced as a pair.
Are the bump stops the same profile both sides?
Did you do any work on the front suspension?
If the front suspension was not re-set to the factory settings it could be that the front suspension is putting additional loading on the R/H rear spring causing the spring to deflect so reducing the clearance between bump stop and body.

[IslipMinor]

Yes, definitely check the front torsion bar. When my mother first bought the Minor, it was 6 years old and had 40,000 miles on the clock.

The nearside rear spring sagged by about 1/2", so naturally we replaced it with a new then currently available BMC spring - no difference!

Adjusted the nearside front torsion bar and bingo, the car was level front and rear.

Rear springs do lose their stiffness, but the reputation of new supplies is very inconsistent these days and well worth checking the torsion bar settings, before removing what could be a perfectly 'good enough' original spring.

[MichaelBeckNZ]

Hi All

Thanks for your replies - The car is one stands at both ends at the moment - The back is under the axle & the front under the chassis so the front suspension bears no load. I will check if one axle stand is further down the chassis & twisting things.

The springs are the ones that have been in service with the car since i bought it - They were just stripped down, painted & new rubbers installed throughout.

What should the bumpstop to chassis difference ideally be for reference?

[philthehill]

You can only accurately check the suspension for correct ride height when the car in down on its wheels and is on a level surface.
The assumption that the suspension is faulty when the car is supported on axle stands should not be made as many things could effect the way the car sits.
The only and correct way to determine bump stop to body clearance is by checking the distances as specified in the BMC Wksp Man Section R illustration R16 when the car is on a level surface.