2fcknfst

He'd only feel that under braking, and it would be at all speeds.

T10Chris

Won't be that. Front axle lift on a stock body car is barely 40 lbs at almost 200 mph, it'll be under 10 lbs below 100 mph.

Celison

Maybe. There's usually contact between the pads and rotor whether you're on the brakes or not. But I agree this is unlikely the cause.

Carlo_Carrera

From what I understand and I maybe wrong, rotors are balanced during manufacturing just like wheels/tires so it might be a fluke but maybe he has a front rotor that somehow went out of balance.

My money though is still on the steering rack.

TheDeckMan

Bent hub/mis pressed into bearing will cause a shake. Inner tie rods?

Are you running spacers? These are always suspect, I have found multiple brands of them that were up to .015" out of parallel from front to back surface with Rennline ones being the worst offenders.

theprf

It's a bent front wheel hub.
Pull off the wheel, caliper, and rotor. Inspect hub surface where the rotor sits for corrosion. Corrosion adds thickness in unpredictable places which causes the rotor/wheel stack to be mounted slightly askew.
If no corrision measure runout on the rotor mounting surface of the hub. It ought to be zero but a few thou is probably ok.
Check both sides.

Jedi767

Feels mostly normal, though I haven't been behind the wheel of enough 996TTs to know for certain.

Many different shops have rebalanced + fitted new tires throughout this process. No one has used a dial indicator, I'll put that on my list of things for a pro shop to check.

Front rotors have been changed.

Yes, factory spacers. I pulled the wheels off last week and checked the front spacers for any play, they are 100% rock solid.

Carlo_Carrera

I like it. Yes.

2fcknfst

We should start a pool on this thread...

JBear

I had a similar issue along time ago, proper wheel balance solved my issue. I had it balanced somewhere else and they did a road force balance and everything was fixed.

2fcknfst

One of my rear twists has a slight bend in it, we cannot seem to balance it out, after straightening the wheel.

This, of course, shows as a slight vibration at 65/70mph, nominal cruising speed for the highway, so it is super irritating.

TheDeckMan

Have you tried it without spacers?

vtec_

I know you run a machine shop..would you be willing to correct mine? Is it possible to detect without knowledge of maching?


I am willing to bet OPs problem has to do with one of his rear axles being bad or out of wack. Ive heard of cars having issues like this and it was the axle, despite the fact that the boot wasnt ripped. I know he said its coming from the steering wheel but perhaps he could try looking there.

Jedi767

I have not. These are the factory spacers every sport techno 996TT or C4S uses. I took the wheels off and checked their fitment and they were rock solid with the rims.

2fcknfst

He makes a valid point though; remove any, and all, potential bad actors, then reassess.