Uneven Tyre Wear, Any Ideas?

[transam]

yea ok, I hold my hands up to not putting the alignment figures in the first post but I was trying to keep it as brief as poss..can you through any light onto what the numbers mean?

I will get it all double checked as you suggest..I'm off to Phuket on Thurs so plan to call into the mitsubishi dealers there, will be interesting to compare them to the krabi nonsense.

I understand but "brief" sometimes overlooks important details.. In any case it's been narrowed now, I already mentioned what the numbers mean previously they mean your 'toe' or scrub angle was way off to the left. On a rear wheel drive vehicle they should be slightly toe'd in on both sides but your's were toe'd in excessively on the right side and excessively toe'd out on the left side which should have been toe'd in slightly..

They toe in the fronts on a rear wheel drive car/truck because the rear tires are pushing so when the fronts contact with the pavement the friction then pulls them outward to track straight and true down the road with the least amount of rolling resistance which equals less tire wear and provides the best fuel mileage. Conversely a FWD car is toe'd outward because the front wheels pull and create even more friction through their grip on the pavement (= more suspension flex) and pull the tires inward when moving the car forward.. The numbers take into account the amount of flex in the front suspension under rolling friction and torque loads and that is the parameters which they use represented by the 'green' readings on the screen, anything red is either toe'd in or out too much depending on what type of car it is..

Also conversely if a vehicle has independent rear suspension those settings will be opposite the fronts regarding which wheels are the driven wheels. This is where so many people who circuit race stock based cars get it all wrong as they continue to use the factory settings in their alignment when the entire suspension geometry is all off now with the multitude of performance changes now made to it and the only way to discover what it should be is to test and make changes accordingly.. Having years of experience with these type of set ups gives you a decided advantage of a starting point but still hours of testing has to be done to determine the given set up on a given car and on a given track surface, there is no "one size fits all" application..

Here's a nice article and illustrations

Excellently written explanation for all.

[WarpSpeed]

Did you have it from new or from a dealer or relation.?.

Bought it new from krabi mitsu end of Feb this year, never lent it out to anyone and always driven carefully..come to think of it, I did come across some huge puddles (or 'standing water' as the posh call it) at night & at speed during the floods a while back, I guess this could knock the alignment out?

Not likely.. Had to be something much worse then that and being out that far something suspension wise would likely have gotten bent in the process. It brings to mind some other thoughts, do you remember the mileage on the truck when you bought it? It's not unheard of that it may have been dropped off the truck when it was being unloaded or someone hitting something during a previous test drive prior to your purchase? Have the alignment guy do a real close up inspection of the tie rods, lower control arms, suspension mounting points and the like while he's under it looking for slight bends and other anomalies..

I had a similar thing happen to me once and because the dealer knew what had happened their attitude was less then cooperative when I had to return the car several times because it was snapping CV joints and literally dropping out axles right on the ground after only weeks of driving on them so it may also explain the dealers attitude in your case. Turns out this car had been rear ended by another vehicle in the left rear quarter panel pretty badly and the chassis was well bent throwing out all of the factory alignment specs stressing all the drive line parts to failure in short order, but they sold it to me as a "new low mileage" demo model and were supposed to disclose any such damage..

[rayinkrabi]

I agree with you Trans, Excellently written explanation for all. thx Warp.

Actually (and not trying to excuse myself for leaving out important details) my original query really was about how on earth could the strange feathered, or tapered sections occur along the surface on a revolving tyre when my non-mechanic logic tells me it should be continuous wear because of the rotation.

Your explanation of scrubbing explains this as I assume this un-natural forward motion causes some kind of 'skipping' resulting (in this case) the rear of every single chunk of pattern along the tyre edge being 'ground' away. A sobering thought as this surely would quickly render the tyres useless?? and of course adversely affect handling...

Regardless, this thread has turned into something far more interesting, your last comment Warp has also got me thinking further as sure enough the motor was handed to me with an 'unexplained' 50 or so Km on the clock, needless to say I got the usual shrugs & smiles when I queried it (through my wife as interpreter)..I know it doesn't sound a lot so I let it go but it was about 50 Km more than I've had on my 3 previous new motors and 2 bikes here! So I def will ask them to check the rods etc. as you suggest.

Thanks again.

[transam]

I agree with you Trans, Excellently written explanation for all. thx Warp.

Actually (and not trying to excuse myself for leaving out important details) my original query really was about how on earth could the strange feathered, or tapered sections occur along the surface on a revolving tyre when my non-mechanic logic tells me it should be continuous wear because of the rotation.

Your explanation of scrubbing explains this as I assume this un-natural forward motion causes some kind of 'skipping' resulting (in this case) the rear of every single chunk of pattern along the tyre edge being 'ground' away. A sobering thought as this surely would quickly render the tyres useless?? and of course adversely affect handling...

Regardless, this thread has turned into something far more interesting, your last comment Warp has also got me thinking further as sure enough the motor was handed to me with an 'unexplained' 50 or so Km on the clock, needless to say I got the usual shrugs & smiles when I queried it (through my wife as interpreter)..I know it doesn't sound a lot so I let it go but it was about 50 Km more than I've had on my 3 previous new motors and 2 bikes here! So I def will ask them to check the rods etc. as you suggest.

Thanks again.

Ah ha. More info .

So really the ride wasn't new .

A simple kirb knock '' can '' bend a track rod arm and put tracking a mile out. My inlaw hit a curb, bent the rod like a banana and BROKE the steering rack housing (Isuzu).

[WarpSpeed]

I agree with you Trans, Excellently written explanation for all. thx Warp.

Actually (and not trying to excuse myself for leaving out important details) my original query really was about how on earth could the strange feathered, or tapered sections occur along the surface on a revolving tyre when my non-mechanic logic tells me it should be continuous wear because of the rotation.

Your explanation of scrubbing explains this as I assume this un-natural forward motion causes some kind of 'skipping' resulting (in this case) the rear of every single chunk of pattern along the tyre edge being 'ground' away. A sobering thought as this surely would quickly render the tyres useless?? and of course adversely affect handling...

Regardless, this thread has turned into something far more interesting, your last comment Warp has also got me thinking further as sure enough the motor was handed to me with an 'unexplained' 50 or so Km on the clock, needless to say I got the usual shrugs & smiles when I queried it (through my wife as interpreter)..I know it doesn't sound a lot so I let it go but it was about 50 Km more than I've had on my 3 previous new motors and 2 bikes here! So I def will ask them to check the rods etc. as you suggest.

Thanks again.

Glad to be of assistance :jap: , hope you find out the culprit and if you do find a bent part it will be quite hard for them to deny though you'll probably not confront them, it's certain you'd get the blame this far down the road but you'll know the truth anyways..

[wandrinstar]

I agree with you Trans, Excellently written explanation for all. thx Warp.

Actually (and not trying to excuse myself for leaving out important details) my original query really was about how on earth could the strange feathered, or tapered sections occur along the surface on a revolving tyre when my non-mechanic logic tells me it should be continuous wear because of the rotation.

Your explanation of scrubbing explains this as I assume this un-natural forward motion causes some kind of 'skipping' resulting (in this case) the rear of every single chunk of pattern along the tyre edge being 'ground' away. A sobering thought as this surely would quickly render the tyres useless?? and of course adversely affect handling...

Regardless, this thread has turned into something far more interesting, your last comment Warp has also got me thinking further as sure enough the motor was handed to me with an 'unexplained' 50 or so Km on the clock, needless to say I got the usual shrugs & smiles when I queried it (through my wife as interpreter)..I know it doesn't sound a lot so I let it go but it was about 50 Km more than I've had on my 3 previous new motors and 2 bikes here! So I def will ask them to check the rods etc. as you suggest.

Thanks again.

Ah ha. More info .

So really the ride wasn't new .

A simple kirb knock '' can '' bend a track rod arm and put tracking a mile out. My inlaw hit a curb, bent the rod like a banana and BROKE the steering rack housing (Isuzu).

Don't scare the poor Chap, its gone from an Alignment to Falling of aTransporter..

[WarpSpeed]

^Dung stirrer! ..... Better then falling into trees ....

[transam]

I agree with you Trans, Excellently written explanation for all. thx Warp.

Actually (and not trying to excuse myself for leaving out important details) my original query really was about how on earth could the strange feathered, or tapered sections occur along the surface on a revolving tyre when my non-mechanic logic tells me it should be continuous wear because of the rotation.

Your explanation of scrubbing explains this as I assume this un-natural forward motion causes some kind of 'skipping' resulting (in this case) the rear of every single chunk of pattern along the tyre edge being 'ground' away. A sobering thought as this surely would quickly render the tyres useless?? and of course adversely affect handling...

Regardless, this thread has turned into something far more interesting, your last comment Warp has also got me thinking further as sure enough the motor was handed to me with an 'unexplained' 50 or so Km on the clock, needless to say I got the usual shrugs & smiles when I queried it (through my wife as interpreter)..I know it doesn't sound a lot so I let it go but it was about 50 Km more than I've had on my 3 previous new motors and 2 bikes here! So I def will ask them to check the rods etc. as you suggest.

Thanks again.

Ah ha. More info .

So really the ride wasn't new .

A simple kirb knock '' can '' bend a track rod arm and put tracking a mile out. My inlaw hit a curb, bent the rod like a banana and BROKE the steering rack housing (Isuzu).

Don't scare the poor Chap, its gone from an Alignment to Falling of aTransporter..

Or worse.

Thought l saw it at the Drags.

I jest.

[rayinkrabi]

Don't think it was my motor on the drag strip..as u know I have problems going in a straight line! You may all have a point though re the transportation..just seen this video of their professional delivery team at work