Leaf spring rear suspensions
Leaf spring rear suspensions
(OP)
If I were to redesign a light truck's rear suspension I would like to reduce the compliance oversteer.
It seems to me that one thing that would help would be to put the hanger at the front of the leaf spring.
Has anyone tried that? What problems did it cause?
I realise it would tend to cause more driveline plunge, and ground clearance might be an issue, but other than that I can't see a downside.
Alternatively, other than fitting a Panhard rod, has anybody got any neat suggestions to get the same effect?
It seems to me that one thing that would help would be to put the hanger at the front of the leaf spring.
Has anyone tried that? What problems did it cause?
I realise it would tend to cause more driveline plunge, and ground clearance might be an issue, but other than that I can't see a downside.
Alternatively, other than fitting a Panhard rod, has anybody got any neat suggestions to get the same effect?
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.





RE: Leaf spring rear suspensions
A similar reduction in compliance oversteer, while maintaining ground clearance, may be available by using a substantially flat spring mounted on top of the rear axle.
Jeeps have used front mounted shackles on the front springs for many years, so it can work. However, it is fairly popular among off-roaders to change the shackle to the rear in order to improve handling. How this would relate to the rear springs is uncertain.
Of course a 3 or 4 link with coil or quarter-elliptic springs is also an alternative.
RE: Leaf spring rear suspensions
RE: Leaf spring rear suspensions
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Leaf spring rear suspensions
Radius rods will be somewhat more expensive than the shackles and bolts they replace, but the springs should also be a little cheaper if no eyes need to be rolled into the top leaf. I do not know what a simple radius rod costs at OEM level, but it might be doable.
Also as the springs are now not used to the same extent to locate the axle, you might be able to put more emphasis on load carrying and less on location characteristics when deciding their dimensions.
Regards
eng-tips, by professional engineers for professional engineers
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RE: Leaf spring rear suspensions
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Leaf spring rear suspensions
Don't see how you could achieve any further cost reduction and maintain pinion angle over the life of the springs.
RE: Leaf spring rear suspensions
Transverse leaf spring with desmodronic shackles?
RE: Leaf spring rear suspensions
But moving the spring hangers to the front will certainly increase the built in rear roll understeer, it may just not be the ideal method to reduce a compliance oversteering problem. Much better would be to try to unload the springs from lateral forces altogether somehow, rather than compensate for any compliance steer.
Perhaps more body roll may allow the built in roll understeer to work as intended ?
RE: Leaf spring rear suspensions
Typically what would happen would be the driver would enter the corner with a certain amount of steering wheel angle, then when the vehicle rolls over he'll have to add some more.
This is rather unsatisfactory.
Now there are other ways round this, but it would be nice to get rid of the root cause.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Leaf spring rear suspensions
Have you considered removing the shackles altogether and using a slider?
Here is a hard slider assy:
http://ww
and there are also poly sliders available.
Use a very flat spring and a slider and you may not require a panhard.
It could be mounted on the front or rear.
Hmmm...use radius rods and do both?
It does somewhat blow your $20 budget.
RE: Leaf spring rear suspensions
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Leaf spring rear suspensions
RE: Leaf spring rear suspensions
RE: Leaf spring rear suspensions
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Leaf spring rear suspensions
RE: Leaf spring rear suspensions
If the problem is rear compliance steering, and compensating for this by introducing some deliberate roll steer is not acceptable, then a panhard bar, or other positive axle location linkage would be about the only alternative.
RE: Leaf spring rear suspensions
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Leaf spring rear suspensions
I can't find a formula to determine the springrate of a parabilic leafspring...
Anyone?
Cheers,
HJKort
RE: Leaf spring rear suspensions
RE: Leaf spring rear suspensions
RE: Leaf spring rear suspensions
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.