Suspension Modification

[Mick Hanna]

In an attempt to reduce the wandering steering of my ARR Ruby which behaved very alarmingly on the way to and from the Centenary event at Moreton, I decided to follow the practice of removing one of the front spring shackles and locking it off with a triangular plate. There are a number of articles about this, each with a different variation of the modification. Ian Williams describes one method on this Forum, Terry Griffin (Midland A7 Club) describes his method on the website and (note - no use of Oxford comma made here) another method is described by 'Spanner' on the Hereford A7 Club website.

'Spanners' version sandwiches the leaf spring eye and axle beam with 2 plates, whereas the other two use a single plate, either in front or behind the axle beam. I have decided to use a single plate on the front which will require a spacer to sit in the profiled recess of the axle beam where the upper radius arm mounting is positioned - the anchor.

In none of the descriptions of the modifications does it take you through the process of dismantling and fitting, probably assuming that if you got this far you know what you are doing. In my case, I thought I'd got the weight of the body off the front axle through supporting the chassis further back, so I was very alarmed when the front shackle was finally removed and the spring sprang down under tension!

So here are my questions: 

Firstly, using a flat iron jemmy I can lever the spring upwards, hopefully enough to line up the bolts and plate and fix the darn thing in place, but will this do any damage to the leaf spring or axle beam? 

Secondly, is there something I am overlooking that I need to do?

Sensible advice will be much appreciated.

The picture below is 'Spanner's' sandwhich version.


  Shackle plate 1.png (Size: 748.56 KB / Downloads: 635)

[Reckless Rat]

This mod I presume is only an easy fix if you have a semi-Girling front axle, as it uses the upper radius arm fixing to locate it.

[Howard Wright]

Hi Mick

Have you lifted the body high enough to fully release the front axle?  The axle should be free to move from side to side to allow the spring shackle at the non fixed end to move to allow the fixed shackle pin to fit.

Cheers

Howard

[flywheel1935]

I believe the mod above turns the spring into some kind of panhard rod ?

an alternate option is to increase castor angle by dropping the ball-joint swivel down by an inch or two ??

[Howard Wright]

I believe the mod above turns the spring into some kind of panhard rod ?

an alternate option is to increase castor angle by dropping the ball-joint swivel down by an inch or two ??

Hi Flywheel 

Yes I think the spring does act like a panhard rod.  

Increasing castor may help handing if the the existing castor is insufficient but on a standard Ruby with a well put together axle the castor should be enough. Simply dropping the radius arm ball join without also fitting a wedge under the spring support will put the spring under torsional stress.

Locating one end of the axle, either by pinning the shackle or fixing the damper arm to the axle stops the axle from moving from side to side. It’s a worthwhile modification that doesn’t alter the basic suspension geometry on an original car.

Cheers

Howard

[Mick Hanna]

Howard, I will try to jack the car up a little higher and report back after. Thanks.

Reckless. It is the semi-Girling front axle. One of the reasons I have chosen to only use one plate on the front is because the upper radius arm fixing is deeper at the rear and would require spacers to line up the axle eye bolt and the lower axle beam mounting bolt and I don't think that would be a sensible mod for the modification.

[Ian Williams]

Mick, did you try to do this with the wheels still on the axle and sitting ion the ground? I always remove front axles with wheels taken off the weight of the axle alone is then hanging on the spring. I use a modified jack under the axle to support it form below so I am in a neutral position, the shackles will then slide out without any spring deflection or axle drop.

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As mentioned immobilising one shackle is a reasonable mod to improve side to side front axle swing and makes the spring effectively into a sort of panhard rod.
Mick, regarding the wandering, I would make sure that the tracking is correct, but as mentioned by others castor angle will have a lot of bearing on skittishness if the angle is to small so focus you attention checking that too.

[John Cornforth]

Hi Mick

My Pearl is retrofitted with a semi-girling front axle. The shackles are standard, and the car doesn't wander at all, on a smooth level road it is almost "hands off". So although locking one shackle may have benefits, I wonder if there isn't another cause or causes ?

I did find that a twin-arm front shock absorber made it noticeably more controllable on the bumpier/twistier stuff, as it reduces the "suddenness" with which initial roll happens when going into a corner

[andrew34ruby]

Why don't we all need to do this mod? My early Ruby is original axle etc and no modification to shock absorber. The brakes don't work well, it's noisy and doesn't climb hills well, but the steering is good. No wander, little roll, it is hands off, and no surprises. It bumps when going over speed bumps and doesn't cope well with humps and bumps in a smooth road, but the steering is great.

[David Stepney]

I can echo Andrew's comment. My RP has the factory front axle setup. Yes, it bump steers and is camber sensitive but then so is my Series 3 Landrover. Having driven my Seven over some 15K miles since I have had it I have never had any anxiety with the steering,

My first Seven was all over the road like a frightened rabbit when I first had it, but new kingpins (and resizing the axle eyes!) shackle pins and bushes and new trackrod end pins and bushes transformed the handling. It would appear that, provided the front suspension and steering is in good order, the standard setup seems to work very well.