High misalignment monoballs for rear axle upper links

[Hans]

Anyone used monoballs for the fat end of the upper links at the rear axle? I am tired of having ScanCrap's bushings completely crap out in just a few years and it looks like OE Boge are NLA. I've got monoballs on my '86 panhard bar and don't notice any additional noise, and they're Aurora bearings that have held up, so I'm considering an all-metal solution for the upper links.

So... or

[KoogiA17]

I think Luke uses a linkage with rose joints/heim joints (they have other names) at either end on his rally car. Looks like a mini panhard rod.

I'm going to use an adjustable arm with rose joints rather than the bushes on my 99 because I'm not a fan of the rubber bushes.

[Crazyswede]

are you refering to the single panhard rod or the short links that go from the top of the axle to the body? if the short links are the bushings the red poly ones? poly does not last as long as the original rubber but they are a lot easier to change. I have never had to replace a set once poly was installed but i have seen the poly shock bushings go bad.

I know luke runs sperical bearings on the panhard rod....see products page on this site..i think he runs them on those links too.

[Jordan]

Luke switched out those heims for standard rubber bushes because the mount kept wanting to tear off under rally use.

I use them on my 99 along with the heim jointed panhard rod. They are a little noisier, but not really that bad. I don't know if they are worth the trouble or not...but I suppose you could always change it out again :)

These are mine.

[Luke]

I did run the upper links with heims for a while with the thought that "less slop must be better" but changed back a few years ago because they create a heavy binding in the suspension geometry and were tearing the chassis apart. When one wheels goes into a bump and the other wheel goes into a dip, the axle is subjected to a heavy torque and the little bit flex in the rubber bushings is needed to prevent the binding.
I would recommend just keeping extra set of rear links with fresh bushings in them on the shelf... that way you always have some ready to go ... just keep a set in rotation basically...

[nutcase]

Powerflex do that bush :)

http://www.powerflex.co.uk/product-deta ... t/746.html

[KoogiA17]

Luke, where exactly was the chassis failing?

[KPAero]

I would imagine where the arm mounts to the body at the back of the wheel well?

Any thoughts on using them for a tarmac set up where the car will see fewer yumps and bumps? The ones currently in my hillclimb car are pretty shot. When I found the OEM ones were NLA I ordered heims to make new links with.

[Hans]

I did run the upper links with heims for a while with the thought that "less slop must be better" but changed back a few years ago because they create a heavy binding in the suspension geometry and were tearing the chassis apart. When one wheels goes into a bump and the other wheel goes into a dip, the axle is subjected to a heavy torque and the little bit flex in the rubber bushings is needed to prevent the binding.
I would recommend just keeping extra set of rear links with fresh bushings in them on the shelf... that way you always have some ready to go ... just keep a set in rotation basically...

I guess I will suck it up and just use the ScanCrap, and load a 2nd set of links while I'm at it.

[simo96]

Saab used a combination of hard and softer bushes in the rear axle to get the thing to steer under cornering loads. Dont ask me which was which, I would love to know! I was also told it might be better to use the early trailing arms, which I was told had shorter bushes and less location.
Its something that was learnt using the 96, which when it leans in a corner turns the back axle into the corner regain rear grip. If you use hard bushes you increase this effect and gain rear grip and if you use knackered bushes you get more steering and a looser rear. A period mod was to cut and move the trailing arm mounts up 1/2" on the body shell to reduce the self correcting action of the back axle. What Chris and myself have done is make different centre bush mounts that drop the location by 5-10mm to do the same thing.
Obviously this can make the car swerve down the straights a bit more on gravel!!

[KoogiA17]

Saab used a combination of hard and softer bushes in the rear axle to get the thing to steer under cornering loads. Dont ask me which was which, I would love to know! I was also told it might be better to use the early trailing arms, which I was told had shorter bushes and less location.
Its something that was learnt using the 96, which when it leans in a corner turns the back axle into the corner regain rear grip. If you use hard bushes you increase this effect and gain rear grip and if you use knackered bushes you get more steering and a looser rear. A period mod was to cut and move the trailing arm mounts up 1/2" on the body shell to reduce the self correcting action of the back axle. What Chris and myself have done is make different centre bush mounts that drop the location by 5-10mm to do the same thing.
Obviously this can make the car swerve down the straights a bit more on gravel!!

What effect have you noticed on tarmac if any?

[Geoff]

I've read a section in the Race and Rally Car Source Book by Alan Staniforth about adjusting a rear axle similar to the C900/99 to reduce or induce oversteer. He said to raise or lower the front pivot points of the trailing arms. I seem to remember that lowering the pivot point reduced oversteer. That could be accomplished on a C900/99 by putting a spacer between the body and the bushing block. Similar to what you were saying about the 96 center bushing mounts.

[simo96]

Chris uses 10mm on his longnose race car and I have some 5mm ones and thy help the turn-in to a corner. You will probably have to pack the centre bracket back on a 96 as lowering it makes the axle swing round an arc and therefore away from the car (hard to explain).

[simo96]

Regarding the 99, you need to look at the arc lengths of the main trailing arms and how they apply to the axle position at your normal ride height. Basically you would be looking at the arc driving the axle rearward as the wheel moves up. If you increase this you should get more steering, but it might effect highspeed sweepers and move the axle around more over bumps etc. Also if you have stiff rear suspension you would need more of this effect than with a softer set up which has more movement.
Anyway just an idea and just to get everyone thinking that hard is not always better....

[RS68]

I'm going to try a set of these urethane bushings from MTC on the SPG.
http://www.eeuroparts.com/Main/PartDetail.aspx?id=8908675U
About $30 for the set on eEuro.

Proparts Sweden also has the bushings. I wonder if these are any better than the scantechs. http://www.eeuroparts.com/Main/PartDeta ... d=65340034