Suspension Overview (Edit 11-14)

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Suspension Overview (Edit 11-14)

Post by Amskeptic » Sun Sep 03, 2006 7:49 pm

Every movement of your car passes through the tires. They must communicate your desires to move or stop or turn to the road. They must do this with enough capacity to carry the weight and momentum of the entire vehicle, and they need to do this for thousands and thousands of miles.

Your suspension, in an ideal universe, would be like the legs of a panther hurtling through the forest. Instantaneously reacting to topography, it would maintain perfect contact with the ground helping your car's "paws" (tires) maintain traction.
(and you thought suspension was all about keeping your touche comfy)
VWs do a pretty good job with the above, but its suspension is a passive reactive system. That means it crashes dumbly into bumps and potholes rather than anticipating them. We have to set the suspension and steering to a "best approximate" position (alignment) to cover your tires' orientation through the broadest range of travel.

Tire problems center around peculiar wear. All they really ask from you is to be oriented to the road nicely and filled with an appropriate quantity of air. Peculiar wear usually comes from incorrect air pressure or incorrect orientation to the road via suspension problems.

Suspension problems center around noise, looseness, misadjustment, and poor control of the vehicle's inertia.

Steering is an extension of the suspension. It communicates your directional intentions to the tires through the suspension components. Its problems center around noise, looseness, misadjustment, and poor control of the vehicle's direction.

It is extremely rewarding to have your suspension, steering, and tires, in optimal condition. Many people are not aware of what a joy a VW can be to drive.

12/06/09 The Big But:

The symptoms described below are classic rebuilt VW bus front suspension symptoms.

Center pin bushings:

Replacement bushings both Febi and Meyle and oem VW too, are split and do have an interference fit as they are driven into the center pin bore.

Both Febi and Meyle replacement kits have been showing up sloppy. But there is a question, are the front suspensions of many VW buses getting their center pin bores bored out from many replacements of these bushings? (I am going to try a chrome spray .001 or .002 increase in pin diameter for my next replacement - machine shops do this to crankshafts)

Highway Wander After Ball Joints/Tierods/Drag Links

Particularly with those who report tighter steering the hotter it gets outside, we have had a rash of tight ball joints that ruin your self-correcting action that was designed into the front suspension. If you go whole hog and replace drag link and tie rods and ball joints and center pin bushings all at the same time, you will have such a tight front end that the car will not return to center. You will also find your work doubled on a windy day, because every single correction you must return to center yourself, and half the time you are overshooting a little and it is a PIA, sorry. Many buses I have visited have this tendency, some worse than others. There is no known cure. I had a bad case that I bitched about on theSamba in 2005/2006, and I did every trick in the book including serious negative camber and major toe-in and as much caster as the eccentrics would allow before the camber got too bulloxed. Didn't help. Zerk-fitted the ball joints and lubricated the heck out of them. Didn't help. Excessive tire pressure did. BusBoys did provide a replacement set of ball joints under warranty that had allegedly been fixed of this bad tendency to jam up in the heat, but guess what? Left ball joint came dry and creaky.

Combination Effect

So, with a loose center pin/relay lever even after new bushings, coupled with tight ball joints and drag link and tie rod joints and chinese front wheel bearings that won't allow you to adjust to .001", you have an ill-handling car that wanders and darts and:

Self Steering

For those who notice that the car steers into wind gusts even after they have made allowances for the nasty new steering they paid good money for, you may have a critical issue with rear suspension ride height/toe-out specifications.

Any alignment that follows Bentley/factory specifications, you must ensure correct height down to every last gallon of gas and driver in driver's seat. Your spring plate angles must be on the money and in agreement with each other across the car when you adjust the rear suspension. Check both shocks across from each other front or rear, particularly adjustable Konis, for exactly the same resistance to extension or compression.

Insufficient negative camber or too much toe-out will pivot your car either into the next lane or into the wind and make it veer too much in any manuever. So many of us make the mistake of looking at the rear wheels and assuming that the negative camber is too extreme without first answering the position of the spring plate position. If your car is loaded or has tired torsion bars, you will have increasing negative camber and toe-out and this is as it should be. Only adjust the camber and toe at factory specified height, and if your car can't find it, even when empty, have the alignment shop bunt the rear up a tick with the air pressure powered thingamabob.

My favorite VWs to drive have slightly loose steering components but active self-centering behavior. Then, a windy day is a natural event with plenty of participation but the car does what you expect and it always is trying to return to center so you can let go of the wheel after the gust. Tight steering, ahhhhh, you have to steer into the gust, pull the wheel back, correct that, correct the other, and the car is acting stupid. A sorry state of affairs for people who put their hearts into bringing back their VWs.

Please only incrementially improve your steering/suspension!

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