Steering wheel shakes while driving at high speed

[rockymountainmama]

Hi there,

I have a '99 Forester with 202k miles. The steering wheel shakes when driving at higher speeds, like above 55 mph. Mechanic has already replaced the front axles on both sides and also all 4 brake rotors (although I think this was not a solution for the problem, since the symptom did not occur during braking.) I also had the tires balanced and rotated, then balanced again. Another clue is that it doesn't happen right away; I must be driving for about 20 minutes for this to occur, like perhaps the car or whatever part affected must be warm. Seems to be worse going downhill, and possibly when foot is on neither the brake nor the gas pedal.

Any ideas of what could be occurring here?

Car is a gem otherwise.

Thank you!

Edited May 17, 2022 by rockymountainmama
forgot important detail

[lmdew]

Did they use Subaru axles?  If not, that is a known problem with aftermarket axlex/halfshafts.

I've rebuilt may Subaru halfshafts with new boots, cleaning and greasing the CV joints.

[laegion]

4 hours ago, rockymountainmama said:

Hi there,

I have a '99 Forester with 202k miles. The steering wheel shakes when driving at higher speeds, like above 55 mph. Mechanic has already replaced the front axles on both sides and also all 4 brake rotors (although I think this was not a solution for the problem, since the symptom did not occur during braking.) I also had the tires balanced and rotated, then balanced again. Another clue is that it doesn't happen right away; I must be driving for about 20 minutes for this to occur, like perhaps the car or whatever part affected must be warm. Seems to be worse going downhill, and possibly when foot is on neither the brake nor the gas pedal.

Any ideas of what could be occurring here?

Car is a gem otherwise.

Thank you!

I don't think axles and brakes would cause a problem like this without other noticeable symptoms pointing to one of those. 

Is there any noticeable shaking at really low speeds like under 10mph? It may not show up as vibration but as a gentle swaying of the steering wheel at very low speeds. I had something similar happen with my '95 Legacy and it ended up being defective tires with steel belts that had snapped. The tire store wanted to try everything else including axles and I told them NO, they just didn't want to replace my tires under warranty. They tried balancing them and rotating them several times and it never helped because with defective belts the tire wasn't even completely round anymore...It's possible this is the issue you have and it doesn't show up until your tires are warmed up? If you drive on a really flat surface in between 5-10mph it will become noticeable if it's a defective tire.

There are other things like tie-rod ends, steering rack, poor tire alignment, old worn bushings on the steering rack mounts or on the front suspension, etc. that could cause this problem. Make your mechanic prove the part is the issue before charging you for parts that aren't bad...maybe take it to a Subaru or import mechanic, or even a dealer if this mechanic can't figure it out?

Edited May 18, 2022 by laegion

[rockymountainmama]

Dear @Imdew, Thanks for the comment about Subaru brand axles. I will definitely ask them if they used those.

Dear @laegion, I will certainly try and see if there is any shaking/swaying of the steering wheel at low speeds. I hope I can ask the (100% Subaru) mechanic to "prove" the part is the issue; so far, they are indicating the parts are indeed bad, and I'm not sure with the age and mileage of the car if one could find all kinds of parts that are bad?? Also extremely dry climate may have whatever impacts, it certainly dries out rubber fast (like windshield wipers). 

I did make a phone call to the dealer and (over the phone only, mind you) they suggested it was the control-arm bushings or compliance bushings. Unfortunately, between the Subaru dealer and the Subaru mechanic, the mechanic has been more reliable over the last 20 years...dealer notorious for overcharging, misdiagnosing, etc.

Thank you for the list of other possibilities! I hope they can find out what's wrong. I planned to keep the car to at least 300k mi. Do they even make velour seats anymore? 

[heartless]

16 hours ago, laegion said:

I don't think axles ...... would cause a problem like this without other noticeable symptoms pointing to one of those. 

actually, crap axles can, will, and have caused symptoms like this... 
and as for it not happening right away.. i can see that happening with crap axles... chilly at night, grease in the joints gets stiff... initial driving the grease is still stiff so joints are not sloppy, but slowly warms up, allowing any excess movement in the joints to become noticeable. makes perfect sense to someone that has had it happen.

bad tires (out of round) is possible, but i dont see that not showing right away...

definitely have bushings, tie rod ends, etc looked at.. and yeah.. have the mechanic show you specifically what the problem is before having things replaced.

[1 Lucky Texan]

I'd have brake CALIPERS inspected. maybe one is not sliding.

[idosubaru]

23 hours ago, rockymountainmama said:

I have a '99 Forester with 202k miles. The steering wheel shakes when driving at higher speeds, like above 55 mph. Mechanic has already replaced the front axles

Seems to be worse going downhill, and possibly when foot is on neither the brake nor the gas pedal.

 

You're right - most new car dealerships are not set up well to maintain 20 year old vehicles at all. For a whole host of reasons - not always because they're unfair/unsavory/cheating people - but the supply side of that maintenance demand (customers) is part of the issue too. so I don't fully blame dealers any more than I blame my business owner friends for their relationships and business with high end clients either. 

1. Were the axles and brake work *ALL DONE* because of the vibration issue?
2. Were the vibrations *ALWAYS* present, and the same, before all of that work and now? 

Did they check the inner and outer tie rods, ball joint, and control arm bushings really well?  It's easy to miss those for a variety of reasons that I wouldn't necessarily blame a mechanic for, although I think it unwise to guess on axles/rotors but I don't kknow the full story/context either. 

 

Ask the mechanic to check the bushings by the front control arm- the LARGE SILVER thing in this picture.  It has a bushing inside that is by far the most common bushing to fail and be problematic in a 99 forester:

https://www.carparts.com/details/Subaru/Forester/TrueDrive/Control_Arm/1999/REPS281505.html?TID=gglpla&origin=&utm_source=google&utm_medium=pla&utm_campaign=9649693653&gclid=Cj0KCQjwspKUBhCvARIsAB2IYuvPIoJEl4xtNOr4APgM6YDkzDdt7xs32tg7gSboLqpVwGFiaU5D6fEaAiosEALw_wcB&gclsrc=aw.ds

Those other bushings and ball joint in that photo should be checked to but the one I indicated fails frequently with age/miles which clearly you have.  I've also seen aftermarket ones fail in 1-2 years so even if it's been replaced that's not a definitive check.

Axles - particularly the inner joints could be problematic.  If the mechanic feels compelled to address this as a warranty concern and the symptom *did change some* after the axle replacement - then you could address the axles in 1 of 3 ways: 
1. swap them side to side - this changes the loading areas inside the housing and can reduce symptoms
2. regrease the inner joints - aftermarket axles have notoroiusly poor grease quality and quantity.  Some subaru shops routinely regrease even brand new axles before installing
3. replace the axles - under warranty, used Subaru with fresh grease/boots, or new Subaru axles if available. 

 

18 hours ago, laegion said:

I don't think axles

Aftermarket axles have so many issues they could definitely be the issue.  Although I would expect issues under hard acceleration up a hill, not just coasting down.

 

 

[laegion]

11 hours ago, heartless said:

actually, crap axles can, will, and have caused symptoms like this... 
and as for it not happening right away.. i can see that happening with crap axles... chilly at night, grease in the joints gets stiff... initial driving the grease is still stiff so joints are not sloppy, but slowly warms up, allowing any excess movement in the joints to become noticeable. makes perfect sense to someone that has had it happen.

bad tires (out of round) is possible, but i dont see that not showing right away...

definitely have bushings, tie rod ends, etc looked at.. and yeah.. have the mechanic show you specifically what the problem is before having things replaced.

I'm definitely not saying that axles can't be the issue; but you would see other symptoms such as noise when turning with the wheel at either lock. The same with brakes, the vibration would be unlikely to be the only symptom.

Edited May 19, 2022 by laegion

[heartless]

10 hours ago, laegion said:

......other symptoms such as noise when turning with the wheel at either lock.

not necessarily.  that would kind of depend on just how sloppy the joints are and where....
an inner joint is not going to make any noises when turning, but can cause vibrations. in fact, vibrations are typically caused by the inner joints, not the outer

so yeah, axles are very much suspect here.

[laegion]

On 5/19/2022 at 4:08 AM, heartless said:

not necessarily.  that would kind of depend on just how sloppy the joints are and where....
an inner joint is not going to make any noises when turning, but can cause vibrations. in fact, vibrations are typically caused by the inner joints, not the outer

so yeah, axles are very much suspect here.

While that would cause vibration, I don't think it would cause the wheel to shake since it isn't a vibration at the wheel hub. I can't imagine that the inside cups would be that worn without the outers being so sloppy that they made noise even when not turning corners; but I suppose someone could have re-packed the outer cups without re-packing the inner cups...but like I said earlier there would have been ample warning and other noises and vibrations well before the wear on the inner cups got that bad...I would think
Wheel "shaking" as the OP says it is usually something in the steering or tires, at least in my experience; but I'm just an amateur mechanic; so there is plenty of stuff outside of my experience.

[idosubaru]

2 hours ago, laegion said:

While that would cause vibration, I don't think it would cause the wheel to shake since it isn't a vibration at the wheel hub. I can't imagine that the inside cups would be that worn without the outers being so sloppy that they made noise even when not turning corners; but I suppose someone could have re-packed the outer cups without re-packing the inner cups...but like I said earlier there would have been ample warning and other noises and vibrations well before the wear on the inner cups got that bad...I would think
Wheel "shaking" as the OP says it is usually something in the steering or tires, at least in my experience; but I'm just an amateur mechanic; so there is plenty of stuff outside of my experience.

You’re right - not likely axles and outer joint symptoms are more common amd typically noisy. But inner joints are more symptomatically varied than outers and can exhibit symptoms without noise and before outers. It happens. I’ve seen it.  And If they’re after market - they don’t need wear to be garbage they just need to be installed  !!  lol   

bad inner joints, or inners with old liquified or low grease (one common issue with new aftermarket axles) can cause shaking at specific speeds, driving straight, and no noise. 

“steering wheel shaking” can be ambiguous in terms of being more the drivers experience or the axle/wheel or vehicle chassis.  

not a bad idea to consider given they’ve been chasing this already  and our incomplete history/feeedback about the car. 

Edited May 21, 2022 by idosubaru

[1 Lucky Texan]

have the rear bushings on the LCA been inspected?