Ball joint problem on front suspension arm Evo 6 tme

[super rover]

Originally Posted by Pushpex

I thought the evo 6 had the ball joints in the knuckles, are you putting evo 5 arms on there? If you haven't put the old ones back in, you could try putting the ball joint in the freezer and the arm somewhere warm in the house for a bit, and go over the mating surface with a scotch pad to remove some of the paint

TMEs ran alloy E5 arms

[super rover]

Originally Posted by spn

Yes, the TME used Evo 5 arms, I'd be interested to know why; weight, cost, some other reason.

The Evo 6 arms give a lower roll centre which should be better from a handling perspective but do increase the unsprung weight when compared to the Evo 5 arm.

rally cars tend to drop of edges of roads and gravel track and the like can soon remove the bolts hanging down ,while it may just be coinsidence it could have been considered as lets face it the evo was made as a cometition car ,but i think it was also down to hub flex ,whey they went back to the 5 design

[madmatt]

I've measured the ball joints diameter where they sit in the arm. The factory one is 39.95mm, and the ebay one 40.15mm.

[spn]

Originally Posted by kikiturbo

well, that ball joint weight is just moved to the upright, isnt it?

Position of the roll centre influences how much the car will roll/lean in a corner. Better said it is the distance between the centre of gravity and roll centre that defines the roll moment. The larger the distance between centre of gravity to the roll centre, the more the car will lean in the corner. Now. the real issue is that mcpherson suspension has the roll centre that is not fixed in relation to the car / centre of gravity, but moves with suspension movement. If the axis between the outer ball joint and inner arm joint is close to horizontal that movement will get quite large which is not the best for handling. This is the reason that lowering the car on its own usually makes the handling worse *****ill you stiffen the springs and ARB). Most of the lowered competition cars will have a corrected roll centre, via the extended bottom ball joints or different uprights.

The 6 GSR arms are much heavier; thicker and have a metal plate to mount the inverted joint.

What I meant was lower pivot point relative to the hub, doh! which would raise the roll centre and as you say is advantagous, however having looked more closely, it appears that the pivot point is the same on both arms.

[spn]

Originally Posted by super rover

rally cars tend to drop of edges of roads and gravel track and the like can soon remove the bolts hanging down ,while it may just be coinsidence it could have been considered as lets face it the evo was made as a cometition car ,but i think it was also down to hub flex ,whey they went back to the 5 design

The 6 GSR arms are much stronger than the 5 / TME ones and the ball joint can be easily replaced.

IIRC, the TME was a tarmac spec 6 and the standard 6 was gravel spec, so it would follow that lighter (cheaper) arms would be acceptable as opposed to the stonger arms required for a gravel.

[Pushpex]

Originally Posted by madmatt

I've measured the ball joints diameter where they sit in the arm. The factory one is 39.95mm, and the ebay one 40.15mm.

Try putting the ball joints in the freezer as thermal expansion can make a difference

[madmatt]

Since the seller doesn't want to refund me despite the fact he sold me ball joints that don't fit, I advise people to avoid him. His name on ebay is ziggy-a2z.

Also putting them in freezer and oven won't solve the 0.2mm difference, no need to even try.

[nplatenkamp]

Maybe you can turn them a bit down on a lathe ?

[madmatt]

Originally Posted by nplatenkamp

Maybe you can turn them a bit down on a lathe ?

For sure I could, except now that I've tried to press them into the arm, one ball joint is stiff, not useable anymore (the outer part compresses now the ball joint because it was "crunched" a bit upon fitting). So its just gonna go to the bin.

The most annoying part for me is that the ball joints I wanted to replace were fine. I changed all rears so I thought I would change the fronts as well. "If it works fine, don't mess with it" they say.

[Greenstar]

eBay can be great but also your worst enemy . Beware .....