Spirited Drive -- Now rear Camber Negative

[andrewwynn]

My worn tire pic was tongue in cheek off course, it was more funny when I thought you said only toe in will cause wear, bit yes either will.

[nick325xit 5spd]

Originally Posted by andrewwynn

My worn tire pic was tongue in cheek off course, it was more funny when I thought you said only toe in will cause wear, bit yes either will.

lol. btdt on the reading comprehension.

[andrewwynn]

My understanding on the all toe in is since all joints will have backlash and because as an old engineering saying goes "everything is a spring".

So; to preload the joints in the most favorable way, toe in preloads the outside corners so they don't have to flip over the center.

If you are toe out, then follow through this example;

The left front tire will be stretching the joint to the steering rack.

As you enter a right turn, the tire will go from toe out to toe in right before starting the turn.

This will case the joint to go from tension to compression exactly when you start the turn giving you a moment of literally "floating" where the tire can tramlinine or just feel wishy washy.

Of course "you can't win" the opposite side will do the same when you have toe in, but the outside tire gets a lot more force so will be the dominant feedback.

The more toe in the more preload on the joints the less floating feeling.

With toe of zero, minor differences in road conditions will change which side is favored at random.

[RocketyMan]

So that is why toe out is less stable at high speeds because it tends to wander with any steering input. With toe in, it will drive and "push" towards the centerline of the car. The "floating" feeling is the "instability" the tire will feel at speed. This seems to make sense.

[andrewwynn]

If you don't need to drive your only car it's nice to have the option.

[bcredliner]

Originally Posted by andrewwynn

If you don't need to drive your only car it's nice to have the option.

Someone with 1 car doesn't need to drive it?

[andrewwynn]

My point is: if I do suspension work on my car there is basically a 100% chance I'll need to drive it ca. 200 mi. before I can get into alignment shop so I will definitely do a string alignment before I take it in.

If you have more than one car makes it easier to just leave the car sit until you can take in for alignment.

I can't know before I'm done when I'll be done so I can't set appointment until I am done.

I could likely borrow a car but ten minutes with a string and I don't need to. Toe alignment is a simple task.

[RocketyMan]

Someone made a comment about ride height measuring from fender flare to bottom of rim. I stumbled upon some information regarding rear suspension configuration, tire rim size, and the measurement.

My current configuration is on springs and would correspond to 723 mm. This is about 28.5" in length.

[g300d]

I had a very similar experience wherein after a spirited trip up some mountain roads I developed some rear suspension noise. Camber was also negative past spec.

We found the noise to be a bad ball joint on one of the upper links. Pulling the arm, I noticed the rubber bushing to be largely intact but deflected inward significantly. I decided to replace this link on both sides.

After replacing arm my alignment place was able to get camber back to spec.

I subsequently did this to another E53 with out of spec rear negative camber and it worked for that one too.

[andrewwynn]

It was the outer ball joint on the "wishbone" (rear upper), correct?

I've worked on about 4 similar it's almost always that joint.