[KarthikK]

High speed vibrations usually boil down to wheel balancing issues. Low speed vibes in the region of <50 kmph or so, are more likely to be related to the suspension or bent alloy(s).

Also, please take a look at the tyres themselves when they are rotating on the balancer machine. Sometimes if the tyre/inner belt is damaged, it can be a little 'bent' (seen when rotating) or unevenly worn causing these vibrations beyond a certain speed. Tyre-related symptoms are again usually things which happen at low speeds commonly, but just saying.

[anjan_c2007]

Steering vibration can be unnerving ! You have said that the alloys were damaged. Was there any body damage to the car during the impacts due to which the alloys got damaged ?

If so, please check the car's body. A good indicator is the pattern of tyre wear . If the wear is not even, chances are that the suspensions and / or the body need a relook.

[opendro]

Guys, I appreciate your responses. But please read the problem clearly. I do know that an unbalanced wheel will vibrate and vibration will only increase with speed.

Mine is a specific case of mild vibration with lack of directness in speeds from 100 to 120. It has no issues from 120 till 160 - as solid as a FIAT can be. That is what is making me clueless as I hadn't read or experienced this narrow range of speed before.

Apparently, my damaged alloys were good till 100 kmph and ok till 120 and unpleasant at 140 plus.

[mayankk]

Originally Posted by opendro

Guys, I appreciate your responses. But please read the problem clearly. I do know that an unbalanced wheel will vibrate and vibration will only increase with speed.

Mine is a specific case of mild vibration with lack of directness in speeds from 100 to 120. It has no issues from 120 till 160 - as solid as a FIAT can be. That is what is making me clueless as I hadn't read or experienced this narrow range of speed before.

Apparently, my damaged alloys were good till 100 kmph and ok till 120 and unpleasant at 140 plus.

Read, faced, and understood by many here.
Me too. With the fiesta, this happened around 90, on till 110. Stable post that. Tried balancing at a lot of places, and discarded it as a problem with that. But then went to a proper laser equipped guy, and he told me the exact speeds when the wiggle occurred. Turns out, not all balancers are equal. .
That balancing fixed it up. Balancing shakes will come up in a range, and settle down before or beyond that.

[Sutripta]

^^^
Yes. Resonance.

Regards
Sutripta

[rajeev k]

This is the effect of the critical speed. In your car, the critical speed of the wheels (RPM) falls in the region corresponding to the mentioned range of vehicle speed.
Usually this is taken care of, during the design stage, to ensure that the critical speed is above the operating range.

Is the new wheels OE? Do a proper balancing and if not solved, go for replacement.

[NaveenKD]

Every object, component, sub-System and system has its own Natural Frequency. While designing a System (Car in this case) a NVH engineer first prepares a frequency mapping.
First of source of excitation - What is the frequency at which engine vibrates (during idle RPM), Transmission, Exhaust, Road Noise (From Wheels & Suspension).

Can he make sure that component or an assembly doesn't have a natural frequency in close range of Excitation source? No he cannot .... Now he prepares a frequency mapping of the parts. He first defines what should be the Global modes of BIW (Torsional , Bending and Lateral). Once he sets the target of BIW, with at least 5% isolation from each other he sets targets for Seats (Fore-Aft, Lateral & Torsional), Steering Column ( Vertical & Lateral), Closures ( Pumping Mode). This is to make sure that each subsystem is sufficiently away from each other and doesn't result in Resonance and we end up with high amplitude vibration.

Now what has happened in this case is due to some issue with assembly, the steering column has a new frequency which is same as your vehicle speed at 100~120 KPH ... Mostly a 2nd order or a 3rd order mode. Hence a resonance is happening at that speed and you are feeling the vibration. Once the speed increases the mode is getting isolated and no vibration is felt.

Of course this the theoretical phenomenon, the practical resolution is to either fix the source of excitation or the object under influence.

[ajaypjayaraj]

This happened with me also. Checked balancing and alignment multiple times and confirmed all that was correct, but the vibration in that narrow band of speed somewhere above 100 KMPH just wouldn't go away. Finally the issue was sorted out with spigot rings.

Since you said you replaced it with steel wheels I'm not sure if you would face this problem. Because if it is an OE steel rim, the hub size should be a perfect fit for the car without any play. Usually this occurs with after market alloys as they have a bigger hub hole as they are manufactured for a variety of car models. Just posting the pictures taken from google images for better understanding.

This (hub size - OD of the car)...


...should match with this (hub hole size - ID of the wheel)


If not, at some speed, you will get vibration as the wheel won't be perfectly centred due to the play available. Only by luck can a wheel be perfectly centred if the hub size and hub hole is of different size. A spigot ring is used to fill up this space which will get rid of the vibration. If your wheel hubs are of a different size, try that and your problem will be solved if your wheels are properly balanced and alignment properly done already.

This is a spigot ring


Like I said above, if its an OE steel wheel you are using, it shouldn't be requiring this. But no harm in getting it checked too as you are facing this problem even after proper alignment and balancing.

[sriram.raghavan]

I had the same issue between the speeds 110 to 130 or so in my old ford ikon, the authorized service station mechanic said its the tires. After much contemplation, I did replace the tires and it helped. Your issue could be a different one though.

[opendro]

Thanks guys. I have got some food for thought now. I will try visiting some shops to fix it and let you know if the problem goes away and what fixed it.

Thanks a lot. I really appreciate the inputs.

[opendro]

I gave the car for wheel balance for the two front wheels at Vecto Motors Hosur road Bangalore. They put an extra weight of 5g on one wheel and 10g on another wheel. I have done a long drive on highway last weekend.

The vibration problem is completely gone. I always thought, unbalanced wheel vibrates proportionately to speed. While that is probably still correct, resonance thing brought in the interesting part. I may not fully understand the theory behind.

Anyway, thanks a lot everyone.

[nikhilhm]

Hello again,

Apologies for the late reply, I'm still chasing this problem (steering wheel shimmy while turning between 80 - 120 kmph) and I'm yet to draw a suitable explanation. The VW A.S.S haven't been very helpful either. After months of visiting them almost every weekend they still are unable to diagnose this problem. I've become quite desperate now. As per the kind advice I have received on this post, I have had the Tie rods checked, as well as the Strut mounts, they seem to be fine. My brake discs have been skimmed which has resolved the brake judder issue. But i still experience a wheel shimmy that increases with speed. Its most noticeable between 80 - 120 kmph.

I have had all four wheels balanced. Also, there is no visible tyre wear. I had the Front drive shaft inspected, the boots are intact and there is no external greasing. Also there is no clicking sound while turning, so a bad CV joint could possibly be ruled out (?)

The problem has become worse since I first reported it, as now I get a Vibration in the steering wheel while accelerating below 2000 RPM as well. I'm confident this wasn't present before.

To further elaborate, it feels as if every bump and crack in the road surface is felt through the steering. As per my memory the Polo's steering felt quite solid and unfazed over rough patches. Could this be a problem with the Power steering motor? or the ball joint in the steering column? Needless to say, the power steering warning light does not illuminate, so a motor failure can be ruled out. The shimmy seems to amplify with increase in speed but reduces after 120 kmph.

Can anyone please help me out with this issue? I'm situated in Hyderabad towards Hi-tech city, I'm most willing to go on a test drive with any Team BHP'ian who owns a polo / vento and is experienced in this issue.

[Leoshashi]

Hello all,
I own a 15 year old Maruti 800 DX 5 Speed. Recently got the brakes serviced at a dealer, somehow they messed up something and a problem arose.

Description and nature of the issue

• Steering Vibration upon braking
• Happens from speed 40kmph and beyond
• No pedal or floor vibration
• No sound from brakes or while steering vibration

The disc is original factory installed while the brake pads were pretty old(last changed in 2009)

I followed this thread and narrowed down to the discs. Upon inspection at different MASS, the SA argued that since there was no vibration at pedals, therefore discs are not the only culprit.
He changed the stabiliser bar bushes, overhauled the caliper and upon my request, he also changed the front brake pads.

These changes seem to have fixed the issues to a large extent, and now vibration on steering is felt only for a second if hard braking is done from speeds of 110kmph.
During gentle braking, no such vibrations were reported.

The SA did however report that front right disc had some deflections on surface,but were well within limits.

Some notable points

• RIms are new, installed them a few days back
• Tyres are Bridgestones S322, 2 years/18000kms old
• Did the balancing recently, however they also seem to be done wrongly, as some vibration is felt at 80kmph ONLY sometimes

My question is, what other things can cause this?? If needed, I can consider changing the discs.

Figure1-The changed parts

Figure2- SA checking out any faults in disc

Figure3 The Disc

[SS-Traveller]

Originally Posted by Leoshashi

15 year old Maruti 800 DX 5 Speed...

• Steering Vibration upon braking
• Happens from speed 40kmph and beyond
• No pedal or floor vibration
• No sound from brakes or while steering vibration

...now vibration on steering is felt only for a second if hard braking is done from speeds of 110kmph.
During gentle braking, no such vibrations were reported.

1. Check for looseness, and if required change, steering ball joints & tie-rod ends
2. Check for free movement of steering with front end jacked up/on ramp
3. Tighten steering rack bolts
4. Change strut rubber kit both sides

[paragsachania]

For once do these to rule out few components as it is to with steering vibration:

• Rotate tires or try tires from a different M800
• Check if all the wheel nuts are torqued well
• Like SST mentions, you may want to try a strut from a different car (Healthy one)
• You mention that the Rims are new, why not shift the front ones to rear and check too
• If the ASC agrees, you can install the Rotor Assembly (Including the Hub) of a different car and check this
• Weak Ball joint ends, Lower arms cannot be ruled out although Ball joints could be the primary among these two