Steering feel at higher speeds

[Nmbrsix]

The car has 73k miles on it currently; I bought it in June 2015 with 69k.

When I took it to Tru-Line, I instructed them to look for any suspension components that looked worn and replace them ahead of doing an alignment. I also replaced/upgraded the struts at that time as one was leaking.

This is what they replaced:

-Both front track arms
-LF wheel straightened (removed slight vibration at 70+mph)
-LF wheel bearing (suspect the bent wheel killed it)
-LR control arm (bad ball joint)
-LR track rod
-All 4 struts replaced with new Bilstein HD's; all related hardware replaced with OEM components (strut bearings, etc)
-New Contis have around 1000mi on them now
-4 wheel alignment was performed by the best shop in Seattle (who also did all of the suspension work ahead of the alignment)

All of this work has been done in the past 2400mi, or two Summers of driving. The car is primarily a Summer time highway commuter for me; it hasn't seen any DE/autocross days or anything that would have worn the new tires in an irregular way. This behavior was also present with the old tires and alignment.

I'm suspicious of the tie rods and front control arms, too...is there a standard way to check for wear on them?

[Racer Boy]

Originally Posted by Nmbrsix

The car has 73k miles on it currently; I bought it in June 2015 with 69k.

When I took it to Tru-Line, I instructed them to look for any suspension components that looked worn and replace them ahead of doing an alignment. I also replaced/upgraded the struts at that time as one was leaking.

This is what they replaced:

-Both front track arms
-LF wheel straightened (removed slight vibration at 70+mph)
-LF wheel bearing (suspect the bent wheel killed it)
-LR control arm (bad ball joint)
-LR track rod
-All 4 struts replaced with new Bilstein HD's; all related hardware replaced with OEM components (strut bearings, etc)
-New Contis have around 1000mi on them now
-4 wheel alignment was performed by the best shop in Seattle (who also did all of the suspension work ahead of the alignment)

I agree that you took your car to the best alignment shop in Seattle, That is where I had mine done, and I was greatly impressed with their work; they really know their stuff.

It's strange that the symptom you are getting only occurs over 75 mph. If the problem is a normal mechanical one, it seems like it would show up at all speeds. Is your front bumper cover undamaged? Are all the under-body covers in the front intact? I'm wondering if maybe something with your bodywork is amiss, and causing some lift at higher speeds.

[Nmbrsix]

Originally Posted by Racer Boy

It's strange that the symptom you are getting only occurs over 75 mph. If the problem is a normal mechanical one, it seems like it would show up at all speeds. Is your front bumper cover undamaged? Are all the under-body covers in the front intact? I'm wondering if maybe something with your bodywork is amiss, and causing some lift at higher speeds.

New front belly pan installed this spring; bumper cover undamaged.

The car had this issue with both prior sets of front tires, too, so I can't place the blame on the Contis (although they do tramline more than the others did).

Funny enough--I opened the frunk a couple of days ago to discover that I still had the box containing the OEM suspension for my Mk7 GTI in there. So there is some weight over the front wheels--with no change.

The steering is nice and heavy at lower speeds, only getting light around center at higher speeds.

[Nmbrsix]

Something just occurred to me...

My car came with a non-OEM (likely eBay) rear spoiler. Not the OEM unit.

It does extend, but I have no idea as to whether it has any real effect.

I wonder if that could be causing the higher-speed instability?

[Flavor 987S]

Originally Posted by Nmbrsix

Something just occurred to me...

My car came with a non-OEM (likely eBay) rear spoiler. Not the OEM unit.

It does extend, but I have no idea as to whether it has any real effect.

I wonder if that could be causing the higher-speed instability?

Yes. Aero is off. Too much rear downforce is making the front light, and changing the rake with the front lift.