Preamble: This is probably one area of owning a car that rattles most people – even the ones with new cars. Its causes and cures can be simple but at times defy correct diagnosis - as it’s quite easy to mix them up with ‘front suspension rattles’ due to their proximity with each other.

So in this Article an attempt is being made on as to how to distinguish between the two and take corrective action accordingly.
(To incorporate contents recent mail to Prakash)

1) Type of Front Suspensions:

Nowadays they’re usually of ‘Independent and Mc-Pherson Strut type, generally with but some times w/o ‘Anti-roll’ Bars as well – such as Ford Ikon. Further variations can be whether ‘sub-frame’ or ‘chassis’ mounted and with ‘I’ or ‘A’ type lower arms. Sketches along side illustrate both.

In high performance Cars they can be ‘double wishbone’ type to ‘Torsion bar’ type – amusingly enough the ready and respective examples of these are the now defunct Premier Padmini but still going strong Amby!

All the above variants have their own advantages and dis- advantages. Suffice to say that Mc-Ph-Strut type designs with ‘A’ type lower arms, Anti-Roll Bars and Sub-Frame mounted are the best from points of view of performance, life and rattles but naturally expensive also.

Ready examples of these are the MUL/Baleno and Hyundai/Santro and Accent. The rest like MUL/M800 to Zen to Alto/Wagon-R fall in the other i.e. ‘I’ type Lower Arm and w/o Sub-Frame category.

2) Steering systems:

The most popular system today is the ‘rack and pinion’ type – with or w/o power assist which itself is either ‘Electronic’ as in smaller MUL Cars or ‘hydraulic’ – as in others. The sketches alongside should be self-explanatory.

3) The ‘LOC’:

From the sketches above, it can be seen that the Suspension and Steering are two different systems with their own mountings and a steering system ends with it’s ‘tie or track-rod ends’. However, there’s no denying of the fact that the two are intimately linked and failings of one can reflect on performance of the other.

4) Suspension Noises:

These can be broadly classified into two – i) Healthy an ii) Un-healthy noises. Amongst the former, depending upon the road surface and speed of the car, one can put the various thumps/thuds and ‘swishes’ of healthy Shock Absorbers working their way up and down – so long as they all disappear for good with the bad road surface.

Amongst the unhealthy ones, one can put the various ‘squeaks’, ‘groans’ even on reasonably good surfaces and ‘metallic knock’ type noises - especially when hit by a pot hole or sudden change of direction – as distinct and different from a worn out Drive-shaft ‘rattle’.

Squeaks and groans generally arise from dried-up or worn out suspension rubber-bushes and ‘metallic’ noises from likewise the various ‘ball joints’ or loose mountings of what comprise the system.

It’s worthwhile to keep in mind that damaged Engine/Gearbox ‘Foundations’ can also create Suspension like noises in FWD Cars and one needs a bit of a training or experience to be able to distinguish between the two.

5) Steering Rattles:

Having seen the build-up of a typical Rack and pinion Steering System as in sketches above, it follows that rattles in them can originate from the following locations:

So far so good but the real crunch lies in identifying the source of such rattles as more often than not, with wear and rear setting in, a rattle gets sort of ‘progressive’ i.e. it can ‘shake’ other members of the system into rattling which on their own may not ! Here’s how one can systematically analyse them:

i) Tie-rod end/Rack ball joint:

Premature wear into these can set in by ignoring the need to have all the five Wheels in good ‘dynamic balance’ all the time. This is covered in greater details in another article. This is easily checked out by hoisting the vehicle on a 2-post lift and ‘yawing’ each front wheel to ‘feel’ the slack. What exactly is supposed to be done, its not clear. Yawing it vertically or horizontally.

ii) Rack and/or Pinion wear:

This again is a consequence of neglecting to keep one’s wheels in good balance all the times. You can check it out yourself by – a) parking the vehicle with wheels ‘st-ahead’ on a level ground and b) standing out side the driver side, gently rocking the steering wheel. If there’s no slack per (i) above, then if the slightest of stg wheel motion doesn’t reflect into front wheels motion, it’s an indication of excessive slack between the rack and pinion. If it cannot be rectified by suitably tightening the rack ‘damper-bush’, the only remedy is to replace both with genuine parts at one go. Would this be the case also with `power steering’ cars?

iii) Rack ‘Bush’ Rattles:

These are ‘softer’ in nature and can be easily pinned down by – a) Parking the car on a level ground with engine off and b) ‘rocking’ the stg wheel gently. If one can hear soft thuds from the lhs end of the car even while sitting in the driver seat, the rack bush is the culprit and the only way to get rid of it is to replace with a genuine spare part.

iv) St Column Rattles:

These are relatively easier to identify as one can feel them as of ‘metallic’ in nature and originating within the column – may be extending upto the pinion. Since most Cars’ stg columns now a days have ball bearings at its stg shaft ends, the main culprit of such noises is invariably the one or more of the ‘universal joints’ deployed between the stg wheel and the rack-pinion.

This malady can be set right by suitably ‘tensioning’ the stg column as follows:

(Reproduce from mail to Prakash)

With the foregoing trouble-shoot, most steering rattles can be overcome with lasting success. However if still no go, one is left with little or no choice but to have one’s steering system suitably overhauled, including replacement of all the wear prone parts at one go.

Cutting corners here is not advisable as otherwise, a half-worn part which was otherwise silent will now start rattling due to greater thrusts on it from the replaced/new parts !

Before we conclude this session, let’s explore another common malady – afflicting some times cars as young as 3-yrs/30 kkm. This, however, assumes that the Car’s wheel alignment is in order and the tyres are not under inflated.

6) Stiff Steering:

With the present ‘greaseless’ or ‘lubricated for life’ designs of the various ball joints that comprise a steering system, their initial or sealed lubrication is hardly effective beyond 2-3 years in the Indian context.

Professional garages in their own interest will advise their replacement at a substantial cost but a tried and trusted ‘home remedy’ can be quite effective and long lasting. It’s relatively simple for a DIY person but others not so inclined can also have the treatment done under their supervision using the services of a friendly neighbourhood mechanic.

Here’s what one can do – armed with ½ a litre of fresh Gear Oil, a 2 ml hypodermic syringe with a Vetnary Needle and a ‘plunger type’ Oil Can :
i) Turn the steering to full lock position – either lh or rh.
ii) Fill the syringe to full and pierce the needle into the rubber boot of the tier rod end far enough to reach the metal inside. Squeeze-in 1 ml of oil into it and quickly withdraw.
iii) Repeat the procedure on the Suspension Lower Arm ball joint.
iv) Repeat the above on the other side 2-ball joints.
v) Arm yourself now with the Oil Can filled to the brim and turn the rh wheel to full inside lock.
vi) Remove/slide forward the retaining steel clip of the rack rubber bellow-boot and insert the Oil Can nozzle to an inch or so inside. Squirt-in about 100 ml of gear oil into the boot.
vii) Repeat the above procedure on the lhs.

Take the Car for a short spin now, ensuring to turn the steering from lock to lock as many times as possible. This will facilitate the oils to reach all over the moving surfaces and will thus make a lot of difference to the earlier stiffness.

If the foregoing exercise doesn’t help much, then it can be safely concluded that the front Strut top bearings need refurbishing and that’d call for professional assistance – including atleast half a day’s down time.

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