A-Frame Vs 4 Link Rear

[DaveS3]

Hi Guys.

The disco it going under the knife within 2 weeks for a GQ Diff conversion.
I've been thinking about trying a 4link rear conversion using standard a frame upper mounts and new control arms to try an get rid of some of the slop in the rear end.
I'm hoping the horizontal separation of the rear links will help some of roll.
I have read bits & pieces from Pirate regarding 4 link design, and believe all will be ok - although I haven't crunched any numbers.

I've talked to different people as to which way to go - most opinions are conflicting for numerous reasons.

Lower links are adjustable with GQ bushes, uppers will be Rover/GQ in case it doesn't work.

Does anyone think the 4-link will stiffen the rear end or have any advantage over the 3-link?
(I realize this is dependent on many factors)
It will most likely compromise wheel travel, but I'm not too worried about that, it is handling and stability that are the preferable outcome.

The car at the moment has a sloppy rear end - with all new bushes (inc A frame) within the last 2 months so I am hoping to remedy this.

I am tempted to try it, but would like to see if anyone has either done it, or has an opinion.

The a frame will be easier - but this is a possibility.

Cheers
Dave.

[mcrover]

Are you racing this thing?

If it is sloppy in the rear end then it could be more the springs or shocks if you have already done the bushes.

Why is it you are going to Patrol stuff, is it just to get rid of the slop (which if those parts are not working as they are meant to)it wont or is it because you need stronger drivetrain?

Just seems like it is a bit over kill for what is in your sig as a stock Disco.

Why not just fit some Maxi axels, Mac 4 pinion diff centres (or lockers) and some Maxi drive flanges, get some good quality big bore shocks and some higer rated springs, bump up the rear tyre pressure a bit to stiffen them and see where you are then.

If it still doesnt work you could then sell it all again and then do your conversion, I say this as doing a conversion like this has heaps of little stuff that most people dont even think about and will take twice as long as you think it will and cost twice as much unless you have done it before and you know what to expect.

Dont rely on what you read on the net, go and find someone who has done it and talk to them face to face and have a look for your self before you start is the best advice I could give you.

[Slunnie]

Info doesn't get any better than Pirate, and without doubt I would argue that due to the calibre of people on there and their questioning of everything, that you will get a better response than from any regular person that has done it.

What do you actually mean by roll? Are you looking for more of an increasing roll resistance like what produced by radius arms? If so, then it may be worth checking out the disco2 geometry. If you're not after heaps and heaps of flex its a very well balanced setup, much better than the classics with A-frames, but at the expense of outright articulation. I just cant but help think that by going to a 4 link setup that you will increase the slop in the suspension because the forces through the bushes will increase, and particularly with lateral location of the axle happening through triangulation, and bush deformation will be accentuated through axle movement. The A frame is a pretty solid setup. But, doesn't the Patrol rear setup as a 5 link anyway, and I would have expected this to be a very good setup to bring over anyway, even if the axle is located from the standard Rover mounting points + a panhard.

[DaveS3]

Are you racing this thing?

If it is sloppy in the rear end then it could be more the springs or shocks if you have already done the bushes.

Why is it you are going to Patrol stuff, is it just to get rid of the slop (which if those parts are not working as they are meant to)it wont or is it because you need stronger drivetrain?

Just seems like it is a bit over kill for what is in your sig as a stock Disco.

Why not just fit some Maxi axels, Mac 4 pinion diff centres (or lockers) and some Maxi drive flanges, get some good quality big bore shocks and some higer rated springs, bump up the rear tyre pressure a bit to stiffen them and see where you are then.

If it still doesnt work you could then sell it all again and then do your conversion, I say this as doing a conversion like this has heaps of little stuff that most people dont even think about and will take twice as long as you think it will and cost twice as much unless you have done it before and you know what to expect.

Dont rely on what you read on the net, go and find someone who has done it and talk to them face to face and have a look for your self before you start is the best advice I could give you.

The disco is not stock - the sig is a bit of a joke.
It will be raced probably next year.
The advice about the diffs is good - but I already knew that.
I'm sick of polishing turds.

The conversion is all sussed except the rear upper links - its already started.

As for the comments about talking to people - as I said I have done it.
The guys I have talked to know their stuff, its just that some of the comments where conflicting.

I have a theory, but I want to hear what other people have said.

Cheers
Dave

[PAT303]

I bought a '96 Disco that was like yours,it still had it's original shocks,springs etc and it was sloppy and ill handling.I fitted Koni's all round,sway bar bushes,and chassis bushes and she as good as new.Replacing the diff and re-designing the suspension because of worn parts is overkill.It didn't have these problems from new so it is not a design problem.Patrol diffs aren't a upgrade either,my mates blew two towing our old shooting buggy around the bush,my defender towed it just as far no worries.He got a new center straight away twice,they are a stock item,enough said. Pat

[DaveS3]

Info doesn't get any better than Pirate, and without doubt I would argue that due to the calibre of people on there and their questioning of everything, that you will get a better response than from any regular person that has done it.

What do you actually mean by roll? Are you looking for more of an increasing roll resistance like what produced by radius arms? If so, then it may be worth checking out the disco2 geometry. If you're not after heaps and heaps of flex its a very well balanced setup, much better than the classics with A-frames, but at the expense of outright articulation. I just cant but help think that by going to a 4 link setup that you will increase the slop in the suspension because the forces through the bushes will increase, and particularly with lateral location of the axle happening through triangulation, and bush deformation will be accentuated through axle movement. The A frame is a pretty solid setup. But, doesn't the Patrol rear setup as a 5 link anyway, and I would have expected this to be a very good setup to bring over anyway, even if the axle is located from the standard Rover mounting points + a panhard.

Hi slunnie.
I was certainly not questioning the likes of pirate - only the people I have talked to.
The roll is more slop / lateral movement in the back end.
Your theory about the bush deflection is what I have been thinking about and believe to be the case.
I don't want to touch the 5-link patrol rear end, it's too much mucking around to retro fit to a rover as the rear of the chassis is completely different. I believe the a-frame is a better setup. I have driven a patrol that I have raced in alot, i personally don't like it.

Cheers.

[PAT303]

Now we have abit more info it makes sense.Why don't you look at what they use in the UK,they have been racing them for a long time.There's no point re-inventing the wheel. Pat

[DaveS3]

I bought a '96 Disco that was like yours,it still had it's original shocks,springs etc and it was sloppy and ill handling.I fitted Koni's all round,sway bar bushes,and chassis bushes and she as good as new.Replacing the diff and re-designing the suspension because of worn parts is overkill.It didn't have these problems from new so it is not a design problem.Patrol diffs aren't a upgrade either,my mates blew two towing our old shooting buggy around the bush,my defender towed it just as far no worries.He got a new center straight away twice,they are a stock item,enough said. Pat

Thanks but one bad experience with a Nissan diff doesn't make them 'not an upgrade' - thats almost the 'Nissan Mentality' towards LR :twisted:
(no offense :))

Cheers
Dave.

[Slunnie]

Hi slunnie.
I was certainly not questioning the likes of pirate - only the people I have talked to.
The roll is more slop / lateral movement in the back end.
Your theory about the bush deflection is what I have been thinking about and believe to be the case.
I don't want to touch the 5-link patrol rear end, it's too much mucking around to retro fit to a rover as the rear of the chassis is completely different. I believe the a-frame is a better setup. I have driven a patrol that I have raced in alot, i personally don't like it.

Cheers.
Oh no, I realise that Dave, you've been around for a long time. It was more directed at McRover who probably hasn't been on Pirate.

Is it possible to setup an A-frame with Rose joints at the chassis end perhaps... if the rose joint will take loading like that in terms of direction??? It doesn't get any more locked up than this???? Then run the A-frame to a factory ball joint at the diff???

[lokka]

Thanks but one bad experience with a Nissan diff doesn't make them 'not an upgrade' - thats almost the 'Nissan Mentality' towards LR :twisted:
(no offense :))

Cheers
Dave.

Your right its a frigging down grade the diff in the center at the back will cause nothing but greif and especialy if you want to race it or do any high speed stuff as the angles on the unis will eat out the joints like no tomoro either use a salsbury in tha rear or a tojo conversion into a rover housing dont go backwards by putting in the datto diff you will regret it i know of a few guys who did .....

Oh and stick with the a frame just fit good quality bushes like superpro and good shocks will work beta than a 4/5 link unless the set up is a 4 link with cross over arms ....

[PAT303]

Dave look on the Patrol forum,engines,gearbox's and diff's.The LC forum is the same. Pat

[Slunnie]

Dave look on the Patrol forum,engines,gearbox's and diff's.The LC forum is the same. Pat
The Patrol and LC diffs are still a heap stronger out of the box than Rover kit, and when built they're heaps stronger again than built Rover kit.

[DaveS3]

Is it possible to setup an A-frame with Rose joints at the chassis end perhaps... if the rose joint will take loading like that in terms of direction??? It doesn't get any more locked up than this???? Then run the A-frame to a factory ball joint at the diff???

I don't think this is right type of joint for my application.
I've seen rover chassis crack/bend this mounting point and the idea of a 'solid' joint worries me, it will only transfer the increased action to where is probably shouldn't be.
I am using the car as a daily driver at the moment, and I think the vibes & wear will only be painful.

Cheers.

[DaveS3]

Dave look on the Patrol forum,engines,gearbox's and diff's.The LC forum is the same. Pat


Your absolutely correct - look hard enough and you will find a fault with EVERY vehicle / piece of equipment made.

I'm not comfortable with Rover gear - I've thrashed Nissan gear enough to know it will suit my needs.
I don't have the same power out put as a worked nissan and the car will be lighter.

Cheers
Dave.

[walker]

Hi Dave, I can't believe you are still going on your project. ;)

It is taking almost as long as mine. :D

[Bush65]

I have to agree with Slunnies posts.


...4link rear conversion using standard a frame upper mounts and new control arms to try an get rid of some of the slop in the rear end.
...
Lower links are adjustable with GQ bushes, uppers will be Rover/GQ ...
I'm not sure if you are talking about parallel upper links plus a panhard (like nissan) or triangulated upper links.

Parallel uppers plus panhard should be ok. But the stock A-frame mounting brackets on the cross member will need to be changed to suit parallel uppers.

If triangulated uppers, then IMHO, the chassis mounts are too close together to get good angles for the transverse loads and the GQ bushes will flex too much. Although I'm not sure what you mean by slop, I think this set-up will increase what I would call slop.


...I'm hoping the horizontal separation of the rear links will help some of roll...
Sorry I don't know what you mean.


...Does anyone think the 4-link will stiffen the rear end or have any advantage over the 3-link?
...
The geometry of the 4 link and the details of the mounts will affect the comparison.

Technically, a link is a member that can only resist axial load (tension or compression) and neither end will resist rotation in any direction. So A-frames and front radius arms are not links. It is misleading to call Land Rover rear or front suspension 3 link.

The Land Rover rear suspension, with parallel lower links and upper A-frame performs much like a 4 link with parallel lower and triangulated upper links. But articulation is ultimately limited by the chassis mounts for the lower links, the ball joint and bushes for the A-frame.

So called heim/rose/rod-end joints are not road legal in Australia, so we have rubber or polyurethane bushings.

[sclarke]

:D:D:D:D:D:D:D

Patrol diffs stronger than Rover...........:D:D:D:D:D:D





















My oath they are.....

Dave, i will watch with keen interest as this is a mod that lots dream of but stick with polishing that turd.....



Ohh your car has a scratch, its where my Tweed jacket's zip rubbed on the front guard when i was looking at the Hyclone install........