Drive axle balance?

[wymjym]

I have a slight imbalance in the front end. It has been there +/- over the past 30K miles. Many tire balances and two different sets of tires later I realize that to some degree it is always present.
I have replaced (over the past 15K miles),
BOTH SIDES:
Ball joints
Hubs
Inner/outer tie rods
Sway bar ends
Brake calipers
Brake rotors
Brake pads
Is it possible that the drive axle is causing this?
If so, is there any way that I can confirm the likeliness that the axle is the cause, short of removing/replacing it?

Thanks for any insight

wj

 

[Ishodu]

Did you remove the rotors and make sure the surface where they seat against the hub is clean as well as the hub. If something is in there it will cause the rotors to wobble. It could also be a bad Axle but don't know anyway of checking it other than replacing it or them.

 

[stephen newberg]

Have you had the welds at the tops of the strut towers broken and extended the adjustment camber channels? All Tauri come welded and set this way from the factory and without doing this will often be forever out of camber adjustment.

pax, smn

 

[wymjym]

Rotors have been replaced, removed for work, inspected…I think they are flat and true.
The point being that all of the pieces I have replaced have been done in steps, rather than all at once.
None of these replacements have ever given that moment when you know you have done the correct thing. Sometimes there were slight improvements, other times nothing.
I drove @ 100 miles yesterday, the vibration came and went, was tolerable and not tolerable. The only time that things were pretty smooth was when I was braking, other times the steering wheel is moving left-right from @ 50~55 mph, when I get up to speed (70+ I’m holding the steering wheel tight enough that I don’t sense the ‘shake’ any longer. Note: it is not a bouncing feeling


Stephen, one strut tower had the welds cut out. The car has been aligned three times…the specs look good and after the first alignment (when the welds were cut) the adjustment is very, very slight.

wj

 

[wymjym]

More specific info

While driving today I did some experimentation.
The vibration does start to make itself evident @ 50mph and after 60mph or so it lessens only to return @ 85+/-.
The vibration is most noticeable when driving in a straight line, if there are curves it is not apparent, if even driving with a road surface that has a pronounce crown to it (forcing the driver to put slight pressure on the steering wheel left or right) it is not apparent.
So….I went to the top of a long, long hill with a pretty flat road surface. Coasting down the hill in N and moving the steering wheel very slightly left and then right I could notice that the vibration only occurred when the wheels were pretty much centered……example; coasting down the hill, left to right then to left the vibration became apparent only when the wheels were towards the center as soon as you can feel that you are starting to load either wheel/tire more than the other it smooths out.
If I put the car in gear I find that the transmission is dampening some of this vibration which has made it harder to determine exactly what is occurring.

Any thoughts on this?
Axle cv joints? Tires with slipped bands? Steering rack?

HELP!!!!!!


Thanks if advance for any thoughts

Wj

 

[stephen newberg]

This is starting to sound to me like steering rack.

pax, smn

 

[wymjym]

Stephen,
have you seen this as an example of a bad rack?
I ask because I just search @ 50 postings of symptoms of a bad steering rack and non of them indicated the shimmy in the st wheel as a lone indicator (I only saw one even mentioned and they also had bad ball joints which were replaced at the same time) and I don't have any of the noted symptoms. It steers great, tracks fine, centers easily, no noise, both sides require same effort for turn in,
wj

 

[Bob Gervais]

Have you checked the CV joints for play? Usually, a bad inner CV joint will cause vibration issues under acceleration, and often times at deceleration as well.

Grab the axle shaft with one hand, and the joint with the other. Try and rotate them opposingly, and see how much play there is. There should be little, if any, play.

 

[wymjym]

I haven't checked as yet but the vibration is only apparent during cruise/coasting. Mild acceleration will almost nullify the 'shake' however if I'm on the throttle and the tranny shifts hard from 3>4 and the rpms there is an noticable shake in the steering wheel until the rpms rise again.

wj

 

[Bob Gervais]

Well, there's definitely something wrong. Reading your earlier post, about the wheel moving side to side at certain speeds, would normally indicate a wheel bearing/hub, or tire/wheel issue. Bent rim or bad tire perhaps?

This last post, where you mentioned movement in the wheel on a 3-4 shift, sounds like a subframe bushing/motor mount/trans mount issue, or a wheel bearing.

Even though there's been items replaced that I've mentioned as suspected issues, it may not be a bad idea to go through and check all those things over again. Look for any type of looseness, using a helper and a crowbar or other lever if possible. Pay close attention to the control arm bushings at the subframe as well.

 

[stephen newberg]

Stephen,
have you seen this as an example of a bad rack?
I ask because I just search @ 50 postings of symptoms of a bad steering rack and non of them indicated the shimmy in the st wheel as a lone indicator (I only saw one even mentioned and they also had bad ball joints which were replaced at the same time) and I don't have any of the noted symptoms. It steers great, tracks fine, centers easily, no noise, both sides require same effort for turn in,
wj

If it is showing up when you are coasting down a hill in neutral, and then only when the steering is centered and goes away as you steer left or right when coasting down the hill, I think you might have a worn spot on the rack. I have run into this on the cars of others a couple of times over the years, but it is not common.

pax, smn

 

[wymjym]

is there any adjustment on the rack? something to remove minute play?
wj

 

[wymjym]

I just crawled around and find that the right inner tie rod has more play than I noticed 60 days ago (it was replaced by the ft end shop 25K miles ago) and there is a clunk when moving the ssteering wheel from right to left, coming from the right side.
So before I swallow hard and consider the rack replacement I think this inner should be my first move.

are the r and l inner ends the same #?
moog ev328?

wj

 

[bacernate]

Did you have the tires balanced at the same shop everytime? Usually a high speed vibration is tire related. Maybe their machine is out of adjustment or just plain garbage.

 

[wymjym]

Hi Alan,
the tires are good to go
do you kow if the l&r inner are the same part #

wj

 

[Ishodu]

The inners are the same part number. DO both if doing any.

 

[wymjym]

thanks,
I did drivers side last month (400 miles), I guess that is recent enough that I can replace the passenger side and expect them to have the same tolerances (I hope)

will do this and report back later on

wj

 

[wymjym]

found something else

I received the replacement inner tie rod and just prior to ripping everything apart I handled the L&R axles to get a feel for their similarity (play).
The L (drivers) looks good, doesn’t move around it you grab it and I tried turning it.

This is where I see a difference.

The driver’s axle: rotate the tire and hold the inner portion (where it enters the tranny), almost imperceptible ‘slop’. This is after 90K miles.
Passenger side, same procedure and I questimate there is 3~4 degree of movement prior to that force being transferred.

So the question is, although very slight…is 3~4 degree enough slop for me to consider the axle as the culprit? (balance—shaky feeling in steering wheel BUT NOT ALWAYS)

I have not replaced the inner TR yet since I hate ripping everything apart again and again.
If it seems reasonable that this axle might be the problem then I’ll get one and replace both pieces at the same time.


opinions appreciated

wj