Hello, I have a vibration that I can feel through the steering wheel, especially as speeds increase. I have had the alignment done, replaced the tires and replaced the struts.

Any suggestions on what to look for next?

Rotors out of round? Loose wheel bearings?

Two things come to mind.

1) Don't assume the wheels are balanced properly. Get a shop with a road force balancer to re-check. I won't go into details but there is a huge difference between old fashioned dynamic balnce and road force balancing.

https://www.discounttire.com/learn/road-force-balancing

2) Wheels on 914's are lug centric. You want to tighten the lug nuts progressively in an X-patttern to ensure they center properly on the lug nut balls. The shop that did the work may have used a impact gun to nail down 1 lug nut, than the other 3 all in a single step. Wheels could be running with excess radial runout.

Beyond that, there are all sorts of other possibilities like worn ball joints, struts, tie road ends, etc. If it started right after the tires were replaced, I'd start by verifying #1 and #2 above.

Thanks for the info

Thank you, I will start checking.

Center your wheels as you tighten them up:
1) install your wheel with the lugs loosely touching
2) Spin the wheel while looking at the rim of the Wheel (not the tire)
3) Adjust to best true spin.
4) Apply brake and tighten before lowering weight of of vehicle on wheel/tire
5) Lower vehicle
6) Torque to spec

I had the same problem.
Tie rod ends, replaced, magic!

I will take a look, Thanks.

FWIW, while the other examples mentioned are more common, I had a front wheel vibration at speed (60mph+) that was a loose strut screw plug. Allowed just a bit of uncontrolled up/down movement of the shock.

It’s not uncommon that the nut that holds the strut insert in the strut body comes loose. It’s hard to tell since it’s under the dust cap but worth checking.

My front end had all the components replaced new. My wheels were freshly restored and had new tires. It took me getting them balanced 3 times to get them correct. Not all technicians are created equally when it comes to this task. One would think you just get the machine to read out 00 for needed weights but apparently not. I took my car to Roger Krause Racing in Castro Valley and they pulled all 4 wheels and each wheel was 1/2 to 3/4 of an ounce off. They stripped all weights off and rebalanced them to zero and now it rides glass smooth. So, just saying, maybe look at that.

Thanks for the info, I have found this true as well.

I have been battling this on and off with my 20 years of owning my car, the list-

1. Check, check and triple check wheel balance
2. Tires at good pressure
3. Tie-Rod ends in good shape
4. All suspension parts tight including spin nut on shock top
5. Wheel bearings in good shape and properly tightened to hub
6. Align wheel by spinning and looking at rim before torqing down
7. Check for tire flat spots from sitting

Thank you, I would have never checked this.

Thank you, I am taking it to a "pro" on Friday. This will be my first step.

Thanks for the check list. It will be very helpful. I am starting with wheel balance from an expert.

2) Wheels on 914's are lug centric.


@Superhawk996

From mid 72 and on front hubs are hub centric.
Good advice otherwise.
Tangerine racing makes adapters to make rear hubs hub centric. But his problem does seem to be in the front.

Also...What Wheels and tire Do you have?

Let us know if it works. My vibration is coming back, I think my tires are a little flat spotted... need to drive more I think .

Do the redneck trick stick your head out the window and watch the tires of coarse you need someone to drive so you can view the passenger side

I have been fighting this issue for a couple years now. Tried everything listed above, road balanced 3 times before we solved 80% of the problem, even had the rims sent to FUCHS restoration. In fact my car is back at PMS to address this issue alone with other steering related issues. Maybe I need to follow Mikes advise and take a road trip to Roger Krause Racing in Castro Valley.

Short term flat spotting is a very real issue on modern tires post Firestone/Ford/TREAD Act fiasco. Design changes were driven into tire construction that compond the short term flatspotting issue. Occurs across all tire brands. Some constructions worse than others but it is there in all to some degree. Most temporary flat spotting will drive out in just a couple miles but there are constructions out there that require tires to get pretty warm and even then it still can take 5-10 miles for it to really settle down.

If you are really having road balance issues, my preferred solution is drive them enought to get them very warm. Take all tires off the car, leave them on floor in horizontal orientation overnight (Don't stack all 4 vertically either), then do road force in the morning.

Also worth noting some constructions have long term flatspotting that if left long enough (say about 6 weeks) it will never drive out. It won't be terrrible but it will be present and will not go away regardless of what you do. Is even worse if parked when hot, and then left for that extended duration.

If you can't seem to get that last 20% try an on-car wheel balance. Getting hard to find shops that can or will do it but on-car balance accounts for all rotating imbalances including rotors, and/or rear axles & outboard CV's.

https://www.tirerack.com/tires/tiretech/tec...ots%20to%20form.

It just dawned on me for what it is worth. The old expression they don't make them like the used too. Tires now have to be 'GREEN" so the construction may lend itself to unknown problems as Phil has indicated about tires.

Spinning the wheel while the car is jacked up and looking for any eccentricity was hard for me. So...

I read on a previous thread here about jacking the car up in the front, then lowering it so the wheel is mere millimeters off the ground. Rotate the wheel by hand while it is hovering. Find the "high spot" when the slightly eccentric wheel rubs on the ground. Rotate it 180 degrees so the high spot is on top, loosen the lugs, then carefully retighten. The wheel will drop slightly from gravity. Rotate again and make sure the wheel does not rub on the ground.

I would imagine one could loosen the lugs where the wheel was rubbing, lower the car a bit and retighten. Probably achieve the same thing.

Hand tighten, then lower slightly so the wheel contacts the floor, fully tighten and then jack it up and check that nothing changed.

Paul

I have a similar issue.

At 60 to 90mph I will get vibration in the steering wheel for about 1/2 to 1 mile and then it will go away for 10-15 miles and then it comes back. It keeps repeating this general pattern over and over again.

I have been fighting this for along time on and off. I went to 911 hubcentric hubs with new bearings, re-balanced front tires and its FINALLY GONE... for now at least . My factory fuchs actually needed a lot of weights on one of the rims.

I think flatspotting and anything worn can play an issue. Also good tire pressure.

Also if your car is lowered at all you can get bump steer, I just have the basic bump steer kit. Some day maybe the legit one that attaches to the tie-rod ends.

@Coondog - Sorry, I did not see your comment. I am pretty sure you already have all new components in your front suspension. Do you have rubber or poly-bronze bushings? Did you raise your spindles? If so did you also do the tie-rod modification to keep the steering geometry as stock as possible? Checked your wheel bearings for play? I went through all of that before getting the wheels balanced correctly by Roger Krause Racing. But there has got to be great shops near you that do high end cars/wheels. When I took mine to Krause, they spun them w/o touching the weights to show me how bad they were- each wheel was 3/4 to 1 1/4 ounces off. Then they stripped off all weights, cleaned the goo off, then balanced them all to "00". Good luck- having the car ride smooth makes a big difference in your comfort.

My brother and I are heading down to Kent's shop in Torrance, CA on Saturday. We should be there at 0800 and likely be there for the day and then head home. Looking forward to the drive and seeing the guys.

It sounds like you have been chasing this problem and throwing parts at it. Those are the worst. Lots of good places to check have been mentioned. I may have missed it but check the right strut spindle. Bump a curb hard and it can bend enough to create a vibration that would be present at speed.

I agree with a previous post ....I don't drive my 914 often and when it sits for a long time the tires tend to flat spot. Driving a while smooths them out.

That would only manifest during braking.

In Sac???? I doubt.