Leaf and coil sprung axle differences

[Gazzar]

Ah. At the risk of being called a conservative, leave alone and just fit the heystee kit?

Avoids a lot of admin hassle. Insurance, etc.

You can go stage 1 V8 bits if you want CVs. 

 

[Bowie69]

2WD plus V8 = big smiles

[Snagger]

The swivel and Shaft swap gives the standard parts for the discs, which you said you want, and gets you CVs, which may* be better for the LT230, but is there much point in going to the effort of keeping standard brake parts if it requires so many custom other parts, especially shafts?  The brake parts are unlikely to become obsolete - Zeus has been around a long time and has a big customer base for their brake kit, and even so, their discs are (or at least were) standard discs for another vehicle with a bit of simple machining that’d be cheap and easy to have done, and you’d see the discs getting thin and know in advance when to do so.  This is no problem with the Heystee kit, but you pay up front for the future ease and security of sourcing parts.  The alternative plan of custom shafts will be dear, and unless you buy two pairs, would immobilise the vehicle (or render it 2wd only) until you had a replacement made should you break one.

Some people are running LT230s with standard Series axles and say the UJs don’t cause any problem.  A lot of US vehicles use UJs in the front axle.  I wonder if the snatching of the steering in 4wd is an effect of the Series 4wd system having a dog clutch instead of an open diff, forcing both diffs to turn at the same rate and not having the free play to allow the UJs to have their fluctuations masked.  CVs would be better, but may not be essential.

I think it’d be worth making a list of costs, including second hand parts, custom parts, raw materials and tools and your time to work out which option is best for you.  Don’t underestimate the cost of this Frankenaxle you have in mind - workshop machining is usually reasonable, but not insignificant, and you’ll probably end up having to include new wheel bearings and seals, drive flanges and perhaps even stub axles, and the discs, pads and callipers from a scrap axle are unlikely to be in good order, so you may have to allow for new pads, discs and at least the pistons and seals.

[Bigj66]

All very valid points Nick and I don’t disagree with any of them.

In reality, whenever we deviate from standard there will always be additional work required, costs to factor in and safety and engineering challenges to overcome. For me this is the fun part of owning a Landrover and learning new skills as I go, it’s part of the experience. I remember at the start of my build some folk saying I won’t be able to fit a V8 auto into a SWB because of propshafts etc but at the moment, it’s looking that I just might have found the way 🤞.

Yes, buying an off the shelf kit would be simple as would fitting the complete coil axles. I first did that over 30 years ago and that very same Landrover turned up on FB a couple of weeks ago alive and well with those very same axles so we can agree on the longevity of such a conversion.

And all these conversions come with their own particular compromises be it performance or aesthetics. For me personally, the width of the coil axles on a series is a compromise too far for how I want my truck to look but I accept that from the engineering point of view, it delivers on all counts. 
 

I now see that there is an opportunity for me to improve on what I had originally envisaged for my project which was disc brakes and selectable 2WD via the LT230 conversion kit. Even with an off the shelf kit I’m still going to rebuild hubs with bearings, seals, gaskets etc so that will apply no matter which way I go even if I left both axles as standard. With regard to costs, for either the Heystee or Zeus kits I am still looking at the thick end of around £2.5k when you add in the cost of the LT230 conversion and as my TB and gearbox will both be reconditioned units, the money I will have spent on the TB work will be wasted if I then need to strip the centre diff down again to fit the conversion.

I accept that there will be costs for bespoke shafts and the additional risks that you highlight but in the event that my vehicle was disabled by a broken half shaft, then I’m fortunate enough to have access to another vehicle if I need it. As I work from home most of the time and then usually get a taxi to the airport for when I’m abroad on projects, my risk is mitigated even further to a personally acceptable level. In other words, I can manage my day to day life without needing my own car if needs be. If there is a way to reduce those costs then it’s a no brainier to me to at least try.

Time wise, unfortunately I have plenty of it as most of us do at the moment due to these very difficult conditions. From a personal point of view, if I wasn’t able to walk to the workshop every day and work on this project or sit and mull over how I can overcome some of the challenges in front of me, then I would be crawling up the bloody wall by now 🤯.

Even if I don’t end up doing anything to these axles and just leave them standard, having these discussions with you guys and trying to overcome the obstacles will have been good for me.

Anyway, there might be an alternative to all these now.....😉

[missingsid]

Personaly if I had a Series 2 or 3 I would prefer the look of wheels up to the edge of the arches, you can fit wide wheels to do so (you said you had them already) or you can fit coiler axles and std wheels. Iposted a pic on this forum on this topic a year or so (but I cannot find it on my PC) of the rear of my old hybred. I will see if I can get another copy to post here.

My conversion has taken 3 years to complete, mostly as working I have no time, no workshop so outside (can't work in the rain) and when not working plenty of time but no money to do it. I have now got a Series 1 (no option to use full coiler axle due to width) with stronger halfshafts, discs allround incl. X-Eng handbrake and 4 pin diffs for half the cost of Haystee front only discs. However I will allways have the doubt that should I have a major accident my conversion could be questioned even if it is perfectly safe? I guess the only solution is to get an engineers report if I can find an engineeer (not mechanic) to do one.

[Bigj66]

Ok, I’m just putting this out there for discussion.

If you were to fit a full coil axle, then why not one off a later Disco 2 without the swivel housing?

[Bowie69]

Much wider again.

[Bowie69]

Here you go: 

 

[Bigj66]

Just now, Bowie69 said:

Here you go: 

 

Cheers, I’ll have a read through that over a coffee 👍

[lo-fi]

On a purely practical note: be mindful of the points system. You've already lost points on steering, gearbox, engine and brakes. Swapping only 1 axle is still another two points lost, leaving only chassis and suspension. Not lecturing, just a quiet reminder.

Also: it would be easier to fit leaf springs and inset rad panel to a 90. Just as food for thought...

[Bigj66]

15 minutes ago, lo-fi said:

On a purely practical note: be mindful of the points system. You've already lost points on steering, gearbox, engine and brakes. Swapping only 1 axle is still another two points lost, leaving only chassis and suspension. Not lecturing, just a quiet reminder.

Also: it would be easier to fit leaf springs and inset rad panel to a 90. Just as food for thought...

Absolutely and another reason to retain my existing axles although brakes do not count towards the points system.

[Bigj66]

1 hour ago, Bowie69 said:

Here you go: 

 

Do they still have the same wheel stud pattern as a series? Doesn’t mention anything in that thread.

[Bowie69]

7 minutes ago, Bigj66 said:

Do they still have the same wheel stud pattern as a series? Doesn’t mention anything in that thread.

No, totally different.

[missingsid]

After tralling through thousands of pics on my laptop and going back 13 years of posts I have finally found my pics for RRC coiler axles under a Series 2 body!!

Here are the pics of mine with 8 spoke and 3 RRC Steel wheels which gives a good comparision.

The eyebrows are not LR but the body line shows where the wheels are in comparision.

RR Classic Steel wheel and 7.50 SAT

8 Spoke and 7.50 Xtra Grip copy

7.50 SAT om banded Series wheels.

 

So if you stay away from aftermarket wheels a 7.50 is borderline without ayebrows.

[Blanco]

51 minutes ago, Bowie69 said:

59 minutes ago, Bigj66 said:

Do they still have the same wheel stud pattern as a series? Doesn’t mention anything in that thread.

No, totally different.

Specifically RRC, D1 and Defender are 6.5" PCD and usually the wheel is born and centred on the studs. D2, P38 and so on are 120mm PCD and usually carried and centred by the close fitting hub centre which comes in at least two sizes. Later vehicles are possibly different again but that would be outside my experience.

[Bigj66]

1 hour ago, missingsid said:

After tralling through thousands of pics on my laptop and going back 13 years of posts I have finally found my pics for RRC coiler axles under a Series 2 body!!

Here are the pics of mine with 8 spoke and 3 RRC Steel wheels which gives a good comparision.

The eyebrows are not LR but the body line shows where the wheels are in comparision.

RR Classic Steel wheel and 7.50 SAT

8 Spoke and 7.50 Xtra Grip copy

7.50 SAT om banded Series wheels.

 

So if you stay away from aftermarket wheels a 7.50 is borderline without ayebrows.

Cheers but coil axels are not an option for me whether I wanted to or not.

[Bigj66]

With regards to the rear brakes, will the stub axle, calliper bracket, disc and hub off a disc braked Defender 90 bolt to the axle case of a SWB series vehicle? I’ve read some threads about rear disc conversions but they all seem to relate to Salisbury axles and 109s.

Putting the issue of half shaft length to one side for the moment.

I did find this from Jon White in a thread from a couple of years ago but I’m wondering why the complete Defender parts cannot be used?

im using, early 90 drum braked rear stubs, with Range Rover disks hubs and Calipers. I used the Caliper brackets from a disk braked Salisbury rear from a 110 which bolt on after thinning them down by a couple of mm to get the disks correctly aligned (can’t remember the measurement sorry, but it’s easy enough to fly cut a bit off of them on a milling machine). Use 24spline shafts, early “thick” defender drive flanges and it all bolts up.

[Snagger]

No idea.  I only tried a swap on a Salisbury.

[Bigj66]

Just referencing this post from Gazzar in another thread.

There must be a smarter way around the steering track issue, too. I'd hate to lose the ground clearance the parabolics have gained.

An alternative is to hang both the track rod and the drag link out of the front arm, suzuki style:

http://bulletproofsteering.com/steeringsystems.html

Not entirely convinced by this approach, the loss of the taper concerns me, but I don't know why. It should work, and the change to the hole and bolt style tie rod is probably an upgrade.

Steve Parker has a drag link and track control arm adapter kit that allows the steering linkage to remain at the front of the axle in a similar way to the Suzuki kit. This looks like it could avoid the clearance issues at the rear of the axle for the TCA, diff and springs.
 

I also updated Discomikeys thread with this in case anyone was searching for similar information.

 

[Snagger]

No, that is exactly the solution I warned against earlier - reversed Ackerman is the problem, so you’re forcing a skid every time you turn the steering wheel.  Any vehicle like that shouldn’t be on the road.

The axle above is a Series axle with twin leading shoe brakes, so presumably a SIII109 or modified 88.  With the geometry of its arms and swivels pins, Ackerman is correct.  But moving the track rod to the front of the coiler axles with their arm geometry doesn’t work.  I suspect Land Rover would have done that, avoiding the very low and vulnerable position of the track rod on coiler axles, if they could have made the geometry work.

Edited May 8, 2020 by Snagger

[Bigj66]

23 minutes ago, Snagger said:

No, that is exactly the solution I warned against earlier - reversed Ackerman is the problem, so you’re forcing a skid every time you turn the steering wheel.  Any vehicle like that shouldn’t be on the road.

The axle above is a Series axle with twin leading shoe brakes, so presumably a SIII109 or modified 88.  With the geometry of its arms and swivels pins, Ackerman is correct.  But moving the track rod to the front of the coiler axles with their arm geometry doesn’t work.  I suspect Land Rover would have done that, avoiding the very low and vulnerable position of the track rod on coiler axles, if they could have made the geometry work.

But if the axle case is the series one and the hubs are coiler ones orientated to 3 degrees castor with an appropriate spacer between the two to restore the original series WF to WF length, then the Ackerman angle should be maintained as per original series spec shouldn’t it?

As far as I’m aware from the Steve Parker website, that is a standard series axle they’ve fitted their power steering kit to.

[lo-fi]

Do you actually understand the Ackerman principal? That the inner wheel needs to steer at a greater angle than the outer? It's nothing to do with the castor angle and is achieved by offsetting the pivot point on the steering arm laterally in relation to the steering rotation point. The offset needs to go the opposite way if the track rod is mounted fore or aft of the wheels, and herein lies the problem Snagger is describing. 

Reverse Ackerman is exactly what it says on the tin: the inner wheel will steer less than the outer. This does not aim the wheels in the arcs that the wheels need to follow during a turn; the inner naturally describing a smaller radius circle. It's sometimes used in esoteric racing applications: mostly to encourage tyre heating by scrubbing. Never on a road car, despite the assertion above that supposed "experts" claim its fine. Its not. 

Hopefully that makes it a little clearer? 

At the end of the day, if there was a good "bolt on" solution with stock parts, lots of people would have done it and Zeus or Haystee wouldn't be selling disk conversion kits...

[Snagger]

15 hours ago, Bigj66 said:

But if the axle case is the series one and the hubs are coiler ones orientated to 3 degrees castor with an appropriate spacer between the two to restore the original series WF to WF length, then the Ackerman angle should be maintained as per original series spec shouldn’t it?

As far as I’m aware from the Steve Parker website, that is a standard series axle they’ve fitted their power steering kit to.

No.  Ackerman angle is achieved by the geometry rod the track rod and swivel pin separation.  From a plan view, they form a trapezium (rectangle with bevelled ends, like a triangle with its top chopped off).  If the track rod is behind the axle, it must be shorter than the distance between swivel pins.  If it is in front of the axle, the track rod must be longer, which means the swivel arms must cant outward from the swivel pins.  The track rod cannot be made longer on coiler axles or a Series axle with coiler swivels and hubs because: a) the arms are cast and can’t be adjusted, and; b) the brakes are too far inboard to allow the ball joints to be any further out.

It is not possible to fit coiler swivels (with any axle) and have a safe front mounted track rod unless you find a way to make new custom arms that attach to the the top swivel and have ball joints significantly outside the swivel pin axis, like the SI arms but flat, using the camber (inward lean) of the swivel axis to achieve that and running the ball joints as close to the brake disc, with brake shield omitted to make space.  That would require much stronger retaining fixings than the two puny bolts that currently hold the top pin in position, something more akin to the four studs with nearly twiddle the diameter that were used on Series axles to take the steering forces.

[Snagger]

6 hours ago, lo-fi said:

Reverse Ackerman is exactly what it says on the tin: the inner wheel will steer less than the outer. This does not aim the wheels in the arcs that the wheels need to follow during a turn; the inner naturally describing a smaller radius circle. It's sometimes used in esoteric racing applications: mostly to encourage tyre heating by scrubbing. Never on a road car, despite the assertion above that supposed "experts" claim its fine. Its not. 

Racing cars have a factor that alleviates the negatives of reversed Ackerman that most cars in proper road use will not have, at least not in significant values: weight shift.  With the high speeds of racing, as the cars corner, their weight will be shifted to the wheels on the outside of the turn, and little grip is present on the inner wheel.  The amount of scrubbing force and tyre damage is reduced, and that tyre would probably not be getting much grip if it wasn’t being forced to skid anyway because of having so ditties downforce.  But the reversed Ackerman on racing vehicles means the outboard wheel moves a long way for a small steering input without heavy steering from moving both wheels a long way - it is a way of effectively increasing the steering ratio to give very sensitive steering without needing PAS and consequently losing responsiveness and feel.  Completely unnecessary and inappropriate in a road vehicle.

[Bowie69]

This shows it:

https://en.wikipedia.org/wiki/Ackermann_steering_geometry

As above, without changing the swivel arms to be outboard of the swivel pin, you have reverse Ackerman = dangerous on a road car.