Front end shake

[TonyK]

The 87 X1/9 that I imported from New Jersey in 2002 has always had a front end shake, almost like a power wobble on a motor cycle. The steering wheel moves back and forth from left to right. It seems to happen between 50 and 60 miles per hour. It is not apparent less than that speed and over 60 miles an hour it goes away as well.

My initial thoughts were that I had a bent rim, so I have new rims from a Fiat 500, still happens. I have changed the steering rack from another car that I use as a parts car, still no difference. I have changed the strut upper rubber bushes and the outer tie rod ends without it making a difference. I have even replaced the stub shaft on the front right side of the car in hopes that possibly the flange was bent. I have even put a dial gauge on each hub and there is less than .005" run out. Installation of sway bars did not make a difference either. I have also adjusted the toe in from 1/16" to toe out 1/16" and the wobble persists.

The left side stub shaft has not been changed but I am running out of ideas. I am certainly open to suggestions.

TonyK>

Grimsby Ontario Canada.

 

[kmead]

Some wobble is endemic to MacPherson struts, some cars show it more than others. Any chance one of the lower arms inner rubber bushing is worn? Any run out in the inner rack joints? I know you have changed racks once already but you never know.

I would suspect some difference in caster. How is the caster on the two wheels? Much variance between them? Have you replaced the rubber doughnuts? Ever?

 

[dragonsgate]

Sounds like the wheels are wanting to go different ways at higher speed. As mentioned check bushings but also check the brackets holding the bushings and bolts for breaks and excess play. Check the radius rods to see that they are not lose. I take it the tie rod ends and ball joints are ok? Look the rear suspension over as well.

 

[TonyK]

Sounds like the wheels are wanting to go different ways at higher speed. As mentioned check bushings but also check the brackets holding the bushings and bolts for breaks and excess play. Check the radius rods to see that they are not lose. I take it the tie rod ends and ball joints are ok? Look the rear suspension over as well.

Thanks for the replies.

I will look at the radius rods and bushings. Logic suggests that it must be something I have not looked at. You are correct when you state "sounds like the wheels are wanting to go different ways at higher speeds" That is exactly what it feels like. The steering wheel is moving back and forth in oscillation. I have owned an X since 78 and have never had this issue with any of the the cars I have owned (5). I have lots of spare parts to draw from.

Thanks again.

TonyK.

Grimsby Ontario Canada.

 

[ecohen2]

I had / have the same thing occasionally. In my case it seems to be impacted by the tire pressure. I am pretty sure that my tires are round but lopsided from side to side if that is possible... What pressures are you running in the front? At 28 PSI in the front and 30 PSI in the rear the problem is almost completely gone... What that said, it could be something else and the tires are just losing traction at the higher PSI...

Ed

 

[Rupunzell]

Gear head myth. Example Miata's with double A arm suspension are well known for wobble-instability at about 65Mph. This has more to do with suspension system resonance than suspension type.


Bernice

Some wobble is endemic to MacPherson struts, some cars show it more than others.

 

[Rupunzell]

Tell about the tires, front and rear.

What about the current alignment settings? Essentially toe front-rear and how accurate toe is front relative to rear toe. Other item to check is front castor left -vs- right. Castor. Camber is not adjustable on a stock exxe, but can be checked.

Check these first before getting into the suspension bits.


Bernice

 

[TonyK]

Tell about the tires, front and rear.

What about the current alignment settings? Essentially toe front-rear and how accurate toe is front relative to rear toe. Other item to check is front castor left -vs- right. Castor. Camber is not adjustable on a stock exxe, but can be checked.

Check these first before getting into the suspension bits.


Bernice

Had a busy day and did not get a chance to look at the car. As for tires and rims, stock phone dial with 185/60 R13 or 195/45 R15 both have the same issue.
Rear Toe in about 1/16" of an inch, and the front is currently the same. ( String method) It is not the back end vibrating, but the front steering wheel is oscillating.

How camber has been adjusted by installing eccentric bushings in the knuckles where they attach to the strut. But this problem was there from day one when I purchased the car and had done none of this to the car. Caster unsure of and not even sure how to check it, advise welcome on this point.

I was hoping that someone else had this problem and could direct me to the issue, apparently that is not the case.

Thanks for the reply.

TonyK.

Grimsby Ontario Canada

 

[LarryC]

Well, I don't have an immediate answer. But if it is any consolation, I too have developed a similar front end/steering wheel oscillation over the past year. I've checked the usual suspects too. I am still thinking it is too little toe-in, but have not yet gone to more toe-in, so I can't check that off the list yet. What I am saying is, I am waiting for YOU to solve the problem with YOUR hard work. Then I can go do the same fix! I got nothing.

 

[Rupunzell]

Check for a out or round, warped, out of balance brake rotor.


Bernice

 

[Rod Midkiff]

in your first post you said you have tow out. I would think that could be the issue. You want tow in. (more in if you have sloppy suspention)

 

[Paul Valente]

No mention of struts? After balancing the tires and wheels, I would have went for that next. There is always some imbalance and there is always a resonance frequency of the system. I know of nothing in the Macpherson strut that would make it more or less susceptible to wobble and any alignment issue would likely not manifest itself in that way (i.e. you reach a speed where it does something bad but you can drive thorugh to a higher speed where it no longer does it). That is usually an imbance/spring/dampner type of thing.

 

[rx1900]

Hi Tony. In my experience, with the symptoms you describe, about 80 % of the time the cause turns out to be a bent wheel or bad (out of round or shifted belt) tire. Would seem unlikely that one of your tires from each set you have tried is bad, but yes it can happen. And an X is quite sensitive to this. So....would kinda make sense to eliminate this first.

Easy to check. Just mount the wheel/tire onto a balancer machine and watch carefully as it spins. Although you probably had your wheel/tires balanced, there may still be a problem there. I have myself balanced a lot of tires, and yes I can balance an out-of-round tire so the machine comes up zero and shows it to be balanced. But at a certain speed it still will wobble or shake....

I have a decent Hoffmann balancer here in Mississauga. You are welcome to bring all you wheels/tires here and we can check them out. My machine has been "field engineered" to still run with the guard up, so you can get a pretty good look while it spins. No charge for you, but the operator functions better when fueled with Timbits....

If....everything checks out there, then move on. About 15% of the time, your symptoms are cause by something wanky in the steering. I have seen myself a loose tie rod end causing the exact symptoms you describe. Although I think you said you had changed the outer tie rod ends. How about the inner tie rod ends ? And although you said you put in another used rack, perhaps it was not so good either ? On the right end of the rack, there is a bushing that is notorious for wearing out. Perhaps this was bad on your original rack and the used one you installed ? The are also I think a couple of u-joints in the steering column that could have play in them. And there is a splined coupling where the column joins the rack. I have even seen an X with the cinch bolt missing at that coupling.....

So....just jack up the car and grab the wheel at 9 oclock and 3 oclock and check CAREFULLY for any play.

If you are confident that it passes both those tests, keep looking for something strange in the last 5 % of possibilities. The steering rack is mounted in rubber bushings so check those. A bad ball joint or control arm bushing. Or bad radius arm bushings. I suppose a really bad wheel bearing or really bad shock.

Wheel alignment should not usually be the cause of a shimmy.

You asked about caster. That can only be checked on a wheel alignment machine. Although as a rough check, just look at the space between the rear of the tire and the inner fender. Should be the same on both sides.

Good luck. Doug

 

[kmead]

If you have a magnetic digital angle gauge you can measure the caster by verifying the angle of the floor and then the angle of the strut tube.

Caster is the angle through the upper strut mount to a point in front of the tire. On an X this is adjustable by varying the shims behind the rubber doughnuts on the radius rod leading back from the front suspension.

The cause can be a very minor amount of wear in a suspension part which can then cascade into steering wheel movement.

 

[dcioccarelli]

The 87 X1/9 that I imported from New Jersey in 2002 has always had a front end shake, almost like a power wobble on a motor cycle. The steering wheel moves back and forth from left to right. It seems to happen between 50 and 60 miles per hour. It is not apparent less than that speed and over 60 miles an hour it goes away as well.

My initial thoughts were that I had a bent rim, so I have new rims from a Fiat 500, still happens. I have changed the steering rack from another car that I use as a parts car, still no difference. I have changed the strut upper rubber bushes and the outer tie rod ends without it making a difference. I have even replaced the stub shaft on the front right side of the car in hopes that possibly the flange was bent. I have even put a dial gauge on each hub and there is less than .005" run out. Installation of sway bars did not make a difference either. I have also adjusted the toe in from 1/16" to toe out 1/16" and the wobble persists.

The left side stub shaft has not been changed but I am running out of ideas. I am certainly open to suggestions.

TonyK>

Grimsby Ontario Canada.

As the original wheels (and most after market ones) are hub-centric, is it possible that the hubs have an issue causing the wheels not to center properly?

Dom.

 

[kmead]

As the original wheels (and most after market ones) are hub-centric, is it possible that the hubs have an issue causing the wheels not to center properly?

Dom.

Interesting as it is one of the few things not changed, but wouldn’t it happen all the time versus only in a narrow band of speeds?

 

[artz1731]

Have been dealing with many of the same symptoms for years. Adjusting the air pressure helped my issue a lot.

 

[TonyK]

Have been dealing with many of the same symptoms for years. Adjusting the air pressure helped my issue a lot.

I think I have this figured out. Bernice mentioned about a rotor out of round or warped and I was all set to change the front rotors when I realized that I have Uno Turbo rotors and this problem was there before the front brake upgrade. So maybe not the rotors. I had a dentist appointment after work today and I took the Abarth X to the dentist. On the drive back I was at 55 Miles per hour on a newly paved section of road and notice how smooth the ride was and the steering wheel was not oscillating. About a 1/4 mile down the road the smooth pavement ended and the front wheel was dancing again. I had a bit of time to lift the car up on the hoist and I think the radius rod bushing is the issue on the Left side of the car. I can move the rod by hand. Further investigation showed that the nut isn't as far on the rod to compress the rubber bushings and it will not compress any more because it is hitting the bushing sleeve. I removed the nut and large washer and the bushing is crumbling. So these bushings need to be changed. That is not a big issue for me to do on the lift. The issue is can these bushing be purchased locally from Car Quest or Napa? I really get hammered buying from the USA with the shipping charges.

Anyway take a look at the pictures, we must all agree that these bushings need to be changed.

Thanks for all of the comments and ideas.

TonyK.

Grimsby Ontario Canada.

 

[LarryC]

Sounds plausible. Meanwhile in my case I am thinking like Bernice that rotor runnout may come into play, not because it is excessive but because it is near the limit and may have been exacerbated by old brake hoses doing the soft one-way valve behavior. When jacked up the right front wheel has a quite pronounced drag spot. Since the wheel shake is accompanied by a slight pull to the right it seems like there could be a little cycle of excess drag and release going on that would act to generate wheel shake and pull to the right. With new hoses on,the drag has disappeared, but I am awaiting my normal 65 mph drive to see if the shake and pull is still there. Slim chance based on past experience. But hope springs eternal.

 

[lookforjoe]

I had a bit of time to lift the car up on the hoist and I think the radius rod bushing is the issue on the Left side of the car. I can move the rod by hand. Further investigation showed that the nut isn't as far on the rod to compress the rubber bushings and it will not compress any more because it is hitting the bushing sleeve. I removed the nut and large washer and the bushing is crumbling. So these bushings need to be changed. That is not a big issue for me to do on the lift. The issue is can these bushing be purchased locally from Car Quest or Napa? I really get hammered buying from the USA with the shipping charges.

Anyway take a look at the pictures, we must all agree that these bushings need to be changed.

Thanks for all of the comments and ideas.

TonyK.

Grimsby Ontario Canada.

Yeah, those are buggered. I've put ones on from MWB, but they don't last long at all. Would be nice to find a decent replacement that holds up. Keep us informed as to what you use.

EDIT: Vick Auto has poly versions, I ordered those to try. The plain rubber replacements seem to be crap.