Rover 'vs' Disco Suspension Differences

[leehamescort]

G'day, Just after some help on Rover Info

I am looking into using Rangerover or Disco Suspension arms etc for a coil conversion to my 71 Leaf sprung Mistubish Jeep

So planning on using the Rear A frame and Front 3 link arms plus using all the spring & shocky mounts etc grafted onto my chassis and diffs.

The idea is to get the diffs complete with arms and mounts then graft them onto the mitsu matching the standard rover geometry. Aiming to keep the car low as guard clearance is not an issue (running 35's)

using either Early rover or disco parts as they are easy and cheap to get.

Question time:
- Is there any major differences in suspension on different models/years?
- Is there any inherant weak points that need to be rectified/avoided/braced?


Thanks for any help / input.

Cheers
Leeham

[Bush65]

Disco I and classic rangie are similar. Rear has weak lower trailing arms and upper A-frame. Front has radius arms and panhard (3 link is after market not stock).

Disco II has radius arms front and rear. Panhard at front and watts link at rear for transverse location.

Front shockies are pin-pin, inside the coil spring. Rear shockies are pin at bottom and eye at top and lean forward and inward at the top (early were forward one side and rearward on the other). Disco II shockies are different again.

The Disco I shockie mounts on the rear axle, have cups welded to the brackets - these need to be removed so the rubber can flex more. The top eye mount has a nut and washer (rangie has a washer and split cotter pin that allows the rubber to flex) which also restricts flex of the rubber. The result from lack of flex in the rubber is the shockie shaft bends on down travel and breaks due to fatigue.

Don't know much about later rangies. Disco II was introduced in about mid 99. Dont know when the classic rangie finished - about late 90's I would guess.

[cloughy]

Want a rolling chassis?

[shakes]

Want a rolling chassis?

I think re-shelling the mitsu onto the rover chassis is a much better idea

[uninformed]

just curious why your choosing rover diffs?????

Serg

[leehamescort]

Thanks for the info john, just the sort of info I needed.

Is there a big difference in the handling of a watts linkage setup over the A frame? I am not chasing massive flex but want a very stable vehicle.

cloughy, a rolling chassis might be of use if the price is right. Still firming up my plans yet. What model?

Shakes & Uninformed, I am just looking at utilising the suspension arms & geometry from the rover, Sticking with mitsu body & chassis as it is something different and already has suitable drivetrain. I will be using 60 series cruiser diffs as they are strong & cheap.

This is a budget build so aim to utilise parts that are easily available as cheap as possible. Time in the shed with the grinder and welder are what i can afford. The rover suspension gives me good flex and handling and the ease of keeping to existing geometry rather than trying to invent a custom setup.

Thanks again, any more input appreciated.

Cheers
Leeham

[Slunnie]

You will find more suspension travel and articulation from a Disco1/Rangie rear suspension due to the A-frame, and more travel/articulation from a Disco2 front end due to the radius arm design with eye chassis bushes and larger axle bushes.

[uninformed]

You will find more suspension travel and articulation from a Disco1/Rangie rear suspension due to the A-frame, and more travel/articulation from a Disco2 front end due to the radius arm design with eye chassis bushes and larger axle bushes.

Slunnie, do you have some pics of disco 2 front arms, and maybe comparison of axle bushes to disco 1/defender???

Serg

[Slunnie]

You will find more suspension travel and articulation from a Disco1/Rangie rear suspension due to the A-frame, and more travel/articulation from a Disco2 front end due to the radius arm design with eye chassis bushes and larger axle bushes.

Slunnie, do you have some pics of disco 2 front arms, and maybe comparison of axle bushes to disco 1/defender???

Serg

Gday Serg,

I haven't got a comparitive pic, though here is a D2 front (top) and rear (lower). The lengths from pin to axle centre is about 915mm for the front and 840 for the rear. The axle bushes are 69mm dia and 50mm wide and the rubber is single section.

D1 is about 51mm dia and 44mm wide and as I understand some have a metal shell in the middle of the bush part (not the crush tube).


D2 Radius arms:

[uninformed]

thanks mate, good info : )

do you think, regarding the front radius arms, that the eye bush at chassis end is better than the pin on disco 1, rangerovers, defenders etc...

i know some people think that the pin is not so good for up and down movement, but have seen how much they can move when not conected to an axle, and i would have thought that when articulating the radius arm is twisting which is where the pin would be least restrictive....

i def think the bigger bushes at axle end are an improvement.... plus it looks like the disco 2 arms are 10% longer than def/rangerover/disoc 1 arms..... my d110 arms are 840 from axle center to center of chassis mount/bush

longer arms will travel a greater arc with less bind, i know 10% is bugger all but it all adds up...

Serg

[Slunnie]

No probs mate.

I tend to think that the bigest gains are from the axle bush size, though I would also expect the extra leverage from the length to help also.

Re the chassis bush, I can only hypothesis, though tend to think that as a whole, the D2 has been designed really well to run up to about 10" travel and then after than everything gets a bit more complex. I would expect that the radius arms will travel really well, where everybody seems to be cranking and getting offset bushes etc at the chassis end with the classic radius arms. As you say the advantage of the pin is that it rotates freely, where the D2 is pinned, though the bush at the chassis end isn't like the one at the axle end, its designed to also twist, much like the bushes used in Nissan rear lower links.... only these ones are 50 times bigger. In that respect they do twist, but only up to a certain point... but I would also expect that point to be beyond where a classic radius arm will bind from the drop travel. Its a very good question though, and I haven't tested it out.

[cloughy]

cloughy, a rolling chassis might be of use if the price is right. Still firming up my plans yet. What model?



Cheers
Leeham

84, a slab of Wild turkey will see it yours, no springs and shocks, but they can be arranged

[uninformed]

No probs mate.

I tend to think that the bigest gains are from the axle bush size, though I would also expect the extra leverage from the length to help also.

Re the chassis bush, I can only hypothesis, though tend to think that as a whole, the D2 has been designed really well to run up to about 10" travel and then after than everything gets a bit more complex. I would expect that the radius arms will travel really well, where everybody seems to be cranking and getting offset bushes etc at the chassis end with the classic radius arms. As you say the advantage of the pin is that it rotates freely, where the D2 is pinned, though the bush at the chassis end isn't like the one at the axle end, its designed to also twist, much like the bushes used in Nissan rear lower links.... only these ones are 50 times bigger. In that respect they do twist, but only up to a certain point... but I would also expect that point to be beyond where a classic radius arm will bind from the drop travel. Its a very good question though, and I haven't tested it out.

good points Slunnie,

can you also give the center to center measurement of the axle end bushes for the front arms?

cheers, Serg

[Slunnie]

good points Slunnie,

can you also give the center to center measurement of the axle end bushes for the front arms?

cheers, Serg

Hi Serg,

They are 185mm front and rear. Do you know what the classics come up at?

[uninformed]

good points Slunnie,

can you also give the center to center measurement of the axle end bushes for the front arms?

cheers, Serg

Hi Serg,

They are 185mm front and rear. Do you know what the classics come up at?

just measured my Def110, it looks like 165mm c-c of bush at axle end...

so it looks like the D2 has the bush as close to the axle casing as D1/classic/Def, the difference in length (c-c) accounting for the larger dia bush in the D2..... now if the c-c is further apart it will help with rotational forces under braking, but does it mean they will bind more under flex????....but then the fact the bushes have more rubber(bigger dia) will cancel this out(if it is correct???)

what dia bolt is used at the axle end of D2?

Serg

[Slunnie]

good points Slunnie,

can you also give the center to center measurement of the axle end bushes for the front arms?

cheers, Serg

Hi Serg,

They are 185mm front and rear. Do you know what the classics come up at?

just measured my Def110, it looks like 165mm c-c of bush at axle end...

so it looks like the D2 has the bush as close to the axle casing as D1/classic/Def, the difference in length (c-c) accounting for the larger dia bush in the D2..... now if the c-c is further apart it will help with rotational forces under braking, but does it mean they will bind more under flex????....but then the fact the bushes have more rubber(bigger dia) will cancel this out(if it is correct???)

what dia bolt is used at the axle end of D2?

Serg

Ahhh, the plot thickens and good points!

The D2 chassis bolt is 15mm, the axle bolts are 15.5mm, the actual rubber in the bush is 16.5mm thick - this excludes the crush tube and sleeve

[uninformed]

Ahhh, the plot thickens and good points!

The D2 chassis bolt is 15mm, the axle bolts are 15.5mm, the actual rubber in the bush is 16.5mm thick - this excludes the crush tube and sleeve[/quote]

same size axle bolts as Def....

Serg

[rick130]

thanks mate, good info : )

do you think, regarding the front radius arms, that the eye bush at chassis end is better than the pin on disco 1, rangerovers, defenders etc...

i know some people think that the pin is not so good for up and down movement, but have seen how much they can move when not conected to an axle, and i would have thought that when articulating the radius arm is twisting which is where the pin would be least restrictive....
<snip>

Serg

Serg, here's my take and I agree with your observation.

Been through the holey axle bushes on the 'fender, and since gone urethane (Super pro) all through the front end for at least the same travel.
What appears to be happening is that with the OE rubber bushes the pin ones tend to weld themselves to all the steel around them (even though I'd used rubber grease on installation) and bind the pins up and so a lot of flex also takes place at the diff end, hence why the holey bushes work so well but....
when I went with the Super Pro bushes and greased them right up before install, the pin bushes allow rotation of the radius arm during articulation.

At the moment it's limited by my springs and shocks (admittedly only 10" travel), not the bushes as is normally the case.

Pics here http://www.aulro.com/afvb/technical-cha ... -they.html

[Slunnie]

The holey bushes work because they allow the radius arm to lever up and down on the axle though, not because they can twist on the axle.

[uninformed]

The holey bushes work because they allow the radius arm to lever up and down on the axle though, not because they can twist on the axle.

i think Rick130 wa referring to the stock chassis end of classic rr/disco 1 and def.... and saying that yes the haultech holey bushes work well compared to a total OEM set up because the pin end isnt rotating anyway... i dont think hes disagreeing that they work or how they work....

so one could maybe get more improvement out of a classic rr/disco 1/def front radius arm by using haultech holey bushes AND super pro chassis end bushes......

another question.... if the axle end bushes are further apart, they will reduce roational forces, but will they reduce articulation.... bind earlier than closer togther bushes, all else being equal?

Serg

[Bush65]

......

another question.... if the axle end bushes are further apart, they will reduce roational forces, but will they reduce articulation.... bind earlier than closer togther bushes, all else being equal?

Serg

Correct.

[uninformed]

so a disco 2 has its c-c bush distance (axle end) 12% further apart than classic rr/def/disco 1, but its bushes are 40% larger OD with the same internal dia... plus the disco 2 arms are 10% longer...

enough to make a difference... yes..... but not enough in my opinion for all def/classic rr and disco 1 drivers to go change your radius arms over.... if you were going to do that, you may as well get custom ones made.... say about 1500mm long, disco 2 bushes at axle end, pin end at chassis...

Serg

[Slunnie]

From what I'm hearing, the Superpro bushes flex like slotted bushes also - but without the slot.

[Bush65]

If making custom radius arms, I would use stock Nissan GU slotted bushes.

[Slunnie]

I was thinking about this too.... I reckon though, if you were going custom radius arms to gain more flex, then if I was bent on having radius arms then I'd use an X-link, otherwise link it up.

[uninformed]

links may give you better flex, but i often think for an all round 4x4 that will see speed on road and off, a long radius arm set up would be good...

one thing i dont see is on comp rigs is a good angle from contact patch to chassis mount of front OR rear links..... more importantly the front...

the shallower the angle the more the axle will move up and do its job over bumps at high speed... and long radius arms with the right bushes would flex fine for a winch challenge type rig.

if i was customing my front end i would build long radius arms... links are great for low speed crawlers...

just my thoughts.

Serg

[rick130]

From what I'm hearing, the Superpro bushes flex like slotted bushes also - but without the slot.

I don't know Slunnie.
The front axle to radius arm Super Pro bush feel to have less flex than the slotted bush (very scientific is feel ) although it only uses a centre crush tube and so doesn't have an external sleeve. They also fill the gap right out to the clevis, as they must being a free fitted bush.
They definitely tightened up the ride and steering on road, although the slotted bushes were torn by the time I removed them. (the car would pogo on stopping, just as if you have dead shocks)
Whether they actually deflect as much vertically, I doubt it but

The chassis end of the SP radius arm uses a bush with a circumferential groove to allow more vertical flex (similar to their rear trailing arm bush)
It was very obvious when crawling underneath when I had the car backed up on that little hump how the rotation of the radius arm had totally changed with the change in bushes. With slotted (and OE) axle housing bushes the radius arms tried to stay in the same plane as the chassis rails as the housing articulated, with the SP ones the radius arm is forced to follow the axle housing and so the radius arm pin rotates relative to the chassis.
It's also obvious how the slotted bush allows for more vertical compliance in the bush than the OE bush.
With my current setup, The SP ones are the go, just from a bit better road manners, but if you went to 12"or more travel dampers you would really have to test to see if they gave you full damper travel.

FWIW, the front springs I'm running were over 17" free length when installed, (measured 17.2" on the drivers side) but I'm guessing would have dropped close to or maybe a touch more than 1/2" by now and both bush setups unseat the front spring.