Power washing alloys - Wheel balancing?

imeddyhobbs

Took the car in for a wash today,decided i would give it a good wash and thats what i did,except for the 10 or more places i missed but thats another story

Anyway drove back thru the slow traffic and went home

Went out later on the open road,driving at around 90kpms and the wagon is vibrating so much that it would'nt keep an old prostitute happy

I dont know anything about wheel balancing but i did remember someone telling me what those little lead blocks were on a wheel trim so i looked at the trims and i noticed that the wheel on the front left was missing almost all of its weights(blocks,small 20mm x 10 mm x maybe 3mm thick plates)while the front right had all of its weights intact

2 questions

How does wheel balancing work??
I can get my head around most things but not this one.Example,I'm driving a 4x4 and i get the left wheel bogged down in dirt and a lot of that dirt sticks to the hot trim,the right wheel stays clean and carrys little or no dirt..wheel balancing is not affected,why not?

Why did the balancing bits(what are they called?)come off when i washed the wheels,this has never happened before.

I'm very interested to know how balancing works thou

Seth Brundle

Are you sure there were some there beforehand? Assuming they were there before, they can and do come off - think if the level of abuse they get being that close to the road!
See this for more info on balancing...

imeddyhobbs

kbannon wrote:

Are you sure there were some there beforehand? Assuming they were there before, they can and do come off - think if the level of abuse they get being that close to the road!
See this for more info on balancing...

The car gets no abuse,I'm the only one that drives it,It has 1895km on the clock!I drove It down the M7 without a bother,got it washed and i could'nt go over 85kmph!

It is the wheel on the left that is the problem,I took it off and put on the ****ty spare and it's fine!

imeddyhobbs

I'm still not sure about how 1 wheel can hold loads of muck and the other have none but yet this does not effect balancing,how do these minor little weights explain themselfs?

Seth Brundle

imeddyhobbs wrote:

The car gets no abuse,I'm the only one that drives it,It has 1895km on the clock!I drove It down the M7 without a bother,got it washed and i could'nt go over 85kmph!

It is the wheel on the left that is the problem,I took it off and put on the ****ty spare and it's fine!

I wasn't referring to the abuse the car gets but the abuse a wheel gets.
Think of all the bumps, etc. however small, they must go over. The left wheels usually get more abuse than the right side because they are on the dirtier side of the road.

VeVeX

One wheel may not balance out with the same weights as another.

When balancing a wheel it is rotated on a machine and the machine estimates the amount of weight needed at a particular point or points on the wheel to eliminate a wobble. A wobble can be caused by rim defects through use or manufacturing, tyre irregularities or heavy stuck on dirt.

The amount of weight on one wheel has no relevance to the amount on another.

Esel

Maybe the power wash tore the weight(s) off the wheel rim.

If a wheel is not balanced (and as VeVeX said, it's not about one wheel versus another, but each wheel in isolation), it will result in vibration and a feeling of judder, usually felt in a particular speed range only. For example - everything feels fine until 80kph, then the car seems to shudder all of a sudden. If you reduce speed, it goes away again. If you keep accellerating, the shudder disappears as suddenly as it appeared - in this case at about 110kph.

Rims (or tyres) are not often not in balance straight from the factory. They are spun on a test rig to see if they come to rest at the same point every time. If so, an appropriate weight is fixed to the opposite point of the rim and the test is repeated. When the wheel stops repeatedly at a random (i.e. different) point, the wheel is 'balanced'.

It is important to have all five wheels balanced, not just the front wheels.

Mud does not stay on wheels, it gets flung off by centrifugal force. On the other hand, if a lump is taken out of a tyre by a foreign object or by 'chunking' (a piece of tyre being flung off - normally this happens when remoulds are driven over the recommended max speed of 80kph or if a tyre has a manufacturing flaw), the balance will be affected, and the usual symptoms will be felt. 'Chunking' is much more dangerous, as the tyre may then fail completely and catastrophically at any time.

I'm sure there are many more detailed explanations available if you google.

Hope this helps.

Lucifer

Just a thought, on steel wheels the weights are hammered on to the rim but on alloys they are usually glued on, do u have alloys or steel wheels? If alloys it may be possible that a power hose could lift the glued on weight??

Alun

1) Mud weighs a lot less per unit mass than lead, that's why they use lead weights and not mud ones

2) Mud will tend to distribute itself around the wheel rather than just sticking in one place

and 3) Any big lumps of mud will most likely just fall off through vibration etc.

I'd go with the theory that you just accidentally powerhosed them off.

TychoCaine

sorry to be a pedant Alun but mud weighs exactly the same per unit mass, but a lot less per unit volume.

Gary

OKenora

WHEEL BALANCING:
To get your wheel to rotate smoothly without any vibration it has to be perfect or as near as. this means perfectly round and with an exact equal amount of metal at all points around the wheel. Unfortunately when wheels and tyres are made this does not happen and there can be "heavy" and "light" areas around the rim. Most of this imbalance is usually attributable to the tyre and not the wheel (presuming an undamaged wheel) so it is more correctly called tyre balancing I suppose. What wheel balancing does is to add weight to the light areas and add weight opposite the heavy areas to balance it all out - wheel balancing - making the wheel and tyre rotate smoothly.

On steel wheels the weights are hammered onto the rim usually but to prevent damage to alloy wheels from the hammering and also from corrosion the weights are stuck on.

It is very very common for power washers to blow these stuck on weights off the wheels. Simple answer, go get your wheels re-balanced. it's less common to lose a hammered on weight like this, but it can happen.