wd21 alignment
Moderator: Mark
wd21 alignment
trying to work out what might be causing it to pull to the left and wear the LF tyre on the outer edge. have just had an alignment done on it so the toe is all fine and the torsion bars are both set to the same height so im out of ideas of what it could be now. anyone had this problem before?
Re: wd21 alignment
Was the camber corrected during the alignment?
Re: wd21 alignment
not that i know of. how is that adjusted?
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Crash bandicoot
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Re: wd21 alignment
castor and top inner A arm bushes, they appear fine when stationary turning lock to lock and driving in a striaght line but when the wieght of lateral G forces at speed start coming into play you will find the castor and toe will change due to excessive wear in the bushes.
I had this issue and it solved the problem, I have a one set of KL71's and they are almost at the end of there life but have dead even wear right across the tire.
And what also annoys me too is the white line and nolethane bushes/crap come with the wrong sleeves, the fulcrum is tapered and there sleeves aren't and rely on the nut and washers to hold the inner sleeve in its true position.
the Calmini ones although expensive are well engineered and come with the correct sleeves
P.S camber shims are placed between the fulcrum and the chassis rail on the top arm to adjust the camber, it can also adjust the castor by shimming the rear more then the front of the A arm, Toe in is done via steering rack.
also if you steering has any play you want a slight toe in on the wheel alignment then when braking the wieght goes on and the front wheels pull out true.
I had this issue and it solved the problem, I have a one set of KL71's and they are almost at the end of there life but have dead even wear right across the tire.
And what also annoys me too is the white line and nolethane bushes/crap come with the wrong sleeves, the fulcrum is tapered and there sleeves aren't and rely on the nut and washers to hold the inner sleeve in its true position.
the Calmini ones although expensive are well engineered and come with the correct sleeves
P.S camber shims are placed between the fulcrum and the chassis rail on the top arm to adjust the camber, it can also adjust the castor by shimming the rear more then the front of the A arm, Toe in is done via steering rack.
also if you steering has any play you want a slight toe in on the wheel alignment then when braking the wieght goes on and the front wheels pull out true.
Waiter...there is a drought in my glass.
Re: wd21 alignment
Good post crash
Those Calmini arms are beefy
Just hope they dont foul your shocks at full droop 
Loose wheel bearings, Sloppy balljoints, sloppy tierod ends, worn idler/tension rod bushes will also cause wander/handling issues and prevent it from holding an alignment.
Those Calmini arms are beefy
Just hope they dont foul your shocks at full droop Loose wheel bearings, Sloppy balljoints, sloppy tierod ends, worn idler/tension rod bushes will also cause wander/handling issues and prevent it from holding an alignment.
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Crash bandicoot
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Re: wd21 alignment
lax2wlg wrote:Good post crash
Those Calmini arms are beefy
yeah the Grinder fixed that
Waiter...there is a drought in my glass.
Re: wd21 alignment
Anyone recommend a decent place for an alignment in Palmy?
Just did uca and radius rod bushes, and re-adjusted torsion bars on my wd21 before a wof, the workshop I use for wofs outsources wheel alignments, and by the looks of it they've just done a quick toe and go, has all the same shims and still drives like a haunted shithouse..
Just did uca and radius rod bushes, and re-adjusted torsion bars on my wd21 before a wof, the workshop I use for wofs outsources wheel alignments, and by the looks of it they've just done a quick toe and go, has all the same shims and still drives like a haunted shithouse..
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Crash bandicoot
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Re: wd21 alignment
the bloke in fielding on kimbolton road.
John Bates wheel alignment.
Tony's tyre service
i have all tried and not being 100 % satisfied.
the best job and quickest service i ever had was from a south african bloke at advantage tyres in wanganui (1 Pacific Pl Wanganui). I figured being from SA and seeing alot of 4wds he'd know his stuff and sure did. even took the time to explain how to do it with a level and a measure tape if your out in the bush.
John Bates wheel alignment.
Tony's tyre service
i have all tried and not being 100 % satisfied.
the best job and quickest service i ever had was from a south african bloke at advantage tyres in wanganui (1 Pacific Pl Wanganui). I figured being from SA and seeing alot of 4wds he'd know his stuff and sure did. even took the time to explain how to do it with a level and a measure tape if your out in the bush.
Waiter...there is a drought in my glass.
Re: wd21 alignment
Just what im after, someone to align it properly rather than just setting it to factory specs
Just too busy with work to travel out of town, otherwise id take it back to me old mate at Champion Autos in Pahiatua, did a good job last time
Was told the other day Bates' was best in town, till John himself retired unfortunately
Anyways back on topic, im pretty sure I read on here that the factory specs can promote wear on the LH front outer edge like the OP (and myself) has experienced, think it might of DEATH INC who posted it?
Just too busy with work to travel out of town, otherwise id take it back to me old mate at Champion Autos in Pahiatua, did a good job last time
Was told the other day Bates' was best in town, till John himself retired unfortunately
Anyways back on topic, im pretty sure I read on here that the factory specs can promote wear on the LH front outer edge like the OP (and myself) has experienced, think it might of DEATH INC who posted it?
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Crash bandicoot
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Re: wd21 alignment
Time for a physics lesson. I may have had a tarmac motorsport background but the mystery that is wheel alignment is the same whether your behind the wheel of a go kart of a 50 ton B train.
IF your truck is set up properly there will be slightly more load on the drivers side torsion rod...but dont think it's to do with the driver or the fact that 70% of the time the right hand side of the vehicle carries more wieght then the left.
It's to do with road camber. To allow surface water to drain off, your vehicle will continually want to pull left...so what do you do as the driver..you give it a little right hand down to keep it going straight.
loading up the right hand side rod more then the left gives the right hand side more wieght to bare...wieght = resistance cancelling the vehciles wanton need to drift left.
Part of the result? worn LH front shoulders.
But that is only part of it.
If you ever park in town and have your front wheels at full lock(left or right doesnt matter) you may notice that the outer wheel appears to lean out at the top from the gaurd. you more then likley have too much positive caster
The top outer/balljoint pivot point of the UCA is too far forward compared to the lower arm. Imagine standing at the side of the vehicle looking at the hub/ front tyre , the closer to vertical your top and bottom ball joints the better it will drive.
If the caster is out it has the effect of positive camber when cornering effectively loading up the outer wall of the tyre. Not that a certain amount of castor is a bad thing...if you had none, the front would be more prone to sledging as applying more down force to the outer wall when cornering gives the tyre more bite.... It's a catch 22 situation.
Positive castor will give the steering a more direct feel and more stable at speed...but lets be honest.....
when was the last time you saw a nissan terrano doing laps of pukekoe? its rather unnecessary for a 2.7 TD 1.7 ton SUV to be requiring positive castor for anything over 110 kph
this also has an effect when turning corners at speed naturally once again due to the aforementioned pre loading of the right hand suspension...why you ask?
when turning right, the left hand side is now more inclined to compress more easily then if you were turning left.
The result is that as the front suspension of a WD21/D21/R20 chassis compresses, it changes the camber in relation to its resting height.
this is magnified on the left hand side as it is easier to compress the left front creating more positive camber then the right hand side.
This is where it is Critical to get the fulcrum pin shimmed the correct distance from the chassi rail.... you may find that if you look at your fulcrum pins the right side will have (or should have) more shims then the left.
next on the list and usually the last thing adjusted by a technitian is toe.
All IFS vehicles will run toe in, just due to the nature of being independant the toe is continually changing with every bump and pot hole your drive over.
Solid axle suspension do not suffer from this as badly as IFS as the axis on which the steering pivots is fixed. and there for the link between the two front hubs should always be one fixed distance.
In a SAS situation the castor can be changed by rolling that axle housing forward or back.
It is quite hard to conceputualise, but it isn't one particular factor that can effect handling. it is all of the above and it needs to be changed in minute increments to get it right. too much of one not enough of the other.
Thats enough for now im gettin a head ache, lol.
IF your truck is set up properly there will be slightly more load on the drivers side torsion rod...but dont think it's to do with the driver or the fact that 70% of the time the right hand side of the vehicle carries more wieght then the left.
It's to do with road camber. To allow surface water to drain off, your vehicle will continually want to pull left...so what do you do as the driver..you give it a little right hand down to keep it going straight.
loading up the right hand side rod more then the left gives the right hand side more wieght to bare...wieght = resistance cancelling the vehciles wanton need to drift left.
Part of the result? worn LH front shoulders.
But that is only part of it.
If you ever park in town and have your front wheels at full lock(left or right doesnt matter) you may notice that the outer wheel appears to lean out at the top from the gaurd. you more then likley have too much positive caster
The top outer/balljoint pivot point of the UCA is too far forward compared to the lower arm. Imagine standing at the side of the vehicle looking at the hub/ front tyre , the closer to vertical your top and bottom ball joints the better it will drive.
If the caster is out it has the effect of positive camber when cornering effectively loading up the outer wall of the tyre. Not that a certain amount of castor is a bad thing...if you had none, the front would be more prone to sledging as applying more down force to the outer wall when cornering gives the tyre more bite.... It's a catch 22 situation.
Positive castor will give the steering a more direct feel and more stable at speed...but lets be honest.....
when was the last time you saw a nissan terrano doing laps of pukekoe? its rather unnecessary for a 2.7 TD 1.7 ton SUV to be requiring positive castor for anything over 110 kph
this also has an effect when turning corners at speed naturally once again due to the aforementioned pre loading of the right hand suspension...why you ask?
when turning right, the left hand side is now more inclined to compress more easily then if you were turning left.
The result is that as the front suspension of a WD21/D21/R20 chassis compresses, it changes the camber in relation to its resting height.
this is magnified on the left hand side as it is easier to compress the left front creating more positive camber then the right hand side.
This is where it is Critical to get the fulcrum pin shimmed the correct distance from the chassi rail.... you may find that if you look at your fulcrum pins the right side will have (or should have) more shims then the left.
next on the list and usually the last thing adjusted by a technitian is toe.
All IFS vehicles will run toe in, just due to the nature of being independant the toe is continually changing with every bump and pot hole your drive over.
Solid axle suspension do not suffer from this as badly as IFS as the axis on which the steering pivots is fixed. and there for the link between the two front hubs should always be one fixed distance.
In a SAS situation the castor can be changed by rolling that axle housing forward or back.
It is quite hard to conceputualise, but it isn't one particular factor that can effect handling. it is all of the above and it needs to be changed in minute increments to get it right. too much of one not enough of the other.
Thats enough for now im gettin a head ache, lol.
Last edited by Crash bandicoot on Sat Oct 25, 2014 8:07 pm, edited 4 times in total.
Waiter...there is a drought in my glass.
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Crash bandicoot
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Re: wd21 alignment
To give you an idea for visual clues i'll use mine as an example...
On my R20 (A WD21 with a later body on top) the lower arm the steering arm and the axle are all on the same plain...if you were to measure the angle from horizontal while the suspension is at rest on level ground these three all line up.
Ignore the UCA this is shorter and the fulcrum pin sits out further from the chassi then the lower arm pivot points. Hence the arm is shorter and travels in a smaller arc up and down.
It is critical though that the upper control arm travels the same trajectory just on a smaller arc for most of its moving distance to keep camber as true as possible.
now one might ask...why the axle whats that got to do with it. it's quite simple. if the connecting axle are on the same plain at rest then they will be on the same plain at full lock and under full compression or under full droop.
If your caster is out this will change the tighter you turn.
this tells us that the toe will not change. this is how all off road suspension should be.(unless your run a macpherson strut) fark knows what they were thinking.
forget the castor and camber. my front wheel have zero camber and zero caster and is slightly unsteady at 100 kph but as mention, they are not race cars.
This from a wise south african diesel mechanic.
On my R20 (A WD21 with a later body on top) the lower arm the steering arm and the axle are all on the same plain...if you were to measure the angle from horizontal while the suspension is at rest on level ground these three all line up.
Ignore the UCA this is shorter and the fulcrum pin sits out further from the chassi then the lower arm pivot points. Hence the arm is shorter and travels in a smaller arc up and down.
It is critical though that the upper control arm travels the same trajectory just on a smaller arc for most of its moving distance to keep camber as true as possible.
now one might ask...why the axle whats that got to do with it. it's quite simple. if the connecting axle are on the same plain at rest then they will be on the same plain at full lock and under full compression or under full droop.
If your caster is out this will change the tighter you turn.
this tells us that the toe will not change. this is how all off road suspension should be.(unless your run a macpherson strut) fark knows what they were thinking.
forget the castor and camber. my front wheel have zero camber and zero caster and is slightly unsteady at 100 kph but as mention, they are not race cars.
This from a wise south african diesel mechanic.
Waiter...there is a drought in my glass.