Castor correction advice please

[timbo2410]

Hi again everybody, well had the wagon in today for it's 60000 service. All's well apart from the advice to get a castor correction kit fitted urgently as it not only trams badly (which I already knew and thoroughly enjoy the terror), but it's also eating the tyres pretty quickly. Dunno why the kit wasn't fitted as part of an Ironman install (had a load of issues with the installer), but I have been quoted $700 for the kit and fitting. Does that sound about right? I've had a 2 inch Ironman lift (springs, shocks, damper and adjustable tie rod). Any and all advice most welcome

[mudnut]

If I was going to get correction fitted I would go for the Superior radius arms. Probably end up cheaper in the long run, but it is your money.

It is interesting that you are chopping your tyres out. I ran a 2 inch lift for a couple of years and had no such issues. Just had a good wheel aligner that knew his job.

[MudRunnerTD]

Hi again everybody, well had the wagon in today for it's 60000 service. All's well apart from the advice to get a castor correction kit fitted urgently as it not only trams badly (which I already knew and thoroughly enjoy the terror), but it's also eating the tyres pretty quickly. Dunno why the kit wasn't fitted as part of an Ironman install (had a load of issues with the installer), but I have been quoted $700 for the kit and fitting. Does that sound about right? I've had a 2 inch Ironman lift (springs, shocks, damper and adjustable tie rod). Any and all advice most welcome

Sorry? you have a 2" lift only yeah? and someone is telling you you need a $700 Caster Correction? Dont go back to that guy. What are they selling you for $700?

A 2" lift barely needs caster correction and 80% of cars dont have any. it really is an "As Needed" basis for a 2" lift. That being said given your need for a minor correction your options are very very small. Basically you are limited to caster correction bushes in the radius arms only. That is all i would do. If you had 3" lift then go drop boxes IMO. Get another opinion, your being robbed.

[MudRunnerTD]

Hi again everybody, well had the wagon in today for it's 60000 service. All's well apart from the advice to get a castor correction kit fitted urgently as it not only trams badly (which I already knew and thoroughly enjoy the terror), but it's also eating the tyres pretty quickly. Dunno why the kit wasn't fitted as part of an Ironman install (had a load of issues with the installer), but I have been quoted $700 for the kit and fitting. Does that sound about right? I've had a 2 inch Ironman lift (springs, shocks, damper and adjustable tie rod). Any and all advice most welcome

Why did they fit an adjustable Tie rod? or do you mean Drag link? (Front of front diff is Drag Link).

Consider Radius Arm bushes and also 1 new Rear Brake line. Fit the current rear brake line to the front and chuck the front and the new line to the rear. a 2" lift is the limit for the factory brake lines and under full flex you will be stretching them out.

[MB]

Drop boxes, I’m a nuffy as you may do know MudrunnerTD mate :-) Aint them chunky steel farkers on the front chassis rail rock/log hindering mate?


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[timbo2410]

I'm sorry it was drag link (forward of front diff). When I bought the car the suspension had sagged very badly and I had the dreaded wobbles at highway speeds. Went to the local 4x4 centre (Ironman) and was told I needed new springs, steering damper and drag link to correct this . Instead of going for standard springs I could go a 2 inch lift. No problem there. I had the car back and the driving difference was amazing. However, the car trams badly. At this service (at a different mechanic), I asked about the problem. The advice was as above. A castor correction "kit" and 3 hours to fit it. Total of $695 estimate. I did ask about brake line lengths, rear anti-roll bar hangers and the rear brake proportional valve but was told that they didn't need doing.

[mudnut]

$160 for offset bushes From patrolapart. I retract what I posted earlier, but I don't like the idea of these offset bushes. Anyway labour to do the job is always expensive.

As for the proportional valve, I made a bracket and fitted it with the lift. Easy as. A length of steel 3mm by 25mm strap and drill 4 holes.

[MudRunnerTD]

Drop boxes, I’m a nuffy as you may do know MudrunnerTD mate :-) Aint them chunky steel farkers on the front chassis rail rock/log hindering mate?


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Hi mate, i have them on Both my cars. They are Awesome. I have Never been hung up on them, its a Myth. They transform the car.

[MB]

Your beast needs to go in mate if it’s “Traming” suspecting that means running out of carish tarmac lines?
Which tyres you running good bloke ?


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[MudRunnerTD]

I'm sorry it was drag link (forward of front diff). When I bought the car the suspension had sagged very badly and I had the dreaded wobbles at highway speeds. Went to the local 4x4 centre (Ironman) and was told I needed new springs, steering damper and drag link to correct this . Instead of going for standard springs I could go a 2 inch lift. No problem there. I had the car back and the driving difference was amazing. However, the car trams badly. At this service (at a different mechanic), I asked about the problem. The advice was as above. A castor correction "kit" and 3 hours to fit it. Total of $695 estimate. I did ask about brake line lengths, rear anti-roll bar hangers and the rear brake proportional valve but was told that they didn't need doing.

I am not really a fan of Caster Correction bushes either to be honest. Factory rubber bushes for me all day. But, you have very little choice here. at a 2" lift there is simply no other way to do any caster correction other than new radius arms which are expensive and overrated for a 2" lift. Accept that the bushes will chew out and you will be replacing them fairly often.

Call your local Pedders and ask them for a price over the phone for radius arm bushes on a Patrol fitted. or call any 4x4 shop and get a price.

[timbo2410]

I'm running the original Bridgestone DD's and the factory alloy rims. Loads of meat left on them. So are you guys saying that the new radius arm bushes (nylon I think they are now), are rubbish? I just looked up and saw the price of new radius arms ... aaarrrgggghhhhh nope wont be going down that path. So if I'm doing anything it will have to be bushes. Which brand I dont know ...

[MudRunnerTD]

I'm running the original Bridgestone DD's and the factory alloy rims. Loads of meat left on them. So are you guys saying that the new radius arm bushes (nylon I think they are now), are rubbish? I just looked up and saw the price of new radius arms ... aaarrrgggghhhhh nope wont be going down that path. So if I'm doing anything it will have to be bushes. Which brand I dont know ...

yes unfortunately the Nylon bushes by design are harder than rubber so dont flex as well. also with the offset they tend to chew out. You might get 5 years out fo them but likely 1 or 2. If i was you id be fitting offset bushes to sort it out. 100%

[MudRunnerTD]

What i would Actually do is buy new springs and go to a 3" lift allowing you to fit Drop Boxes and never look back. This is Illegal though..... But its bloody Perfect.

[MudRunnerTD]

Your beast needs to go in mate if it’s “Traming” suspecting that means running out of carish tarmac lines?
Which tyres you running good bloke ?


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Yeah it will be Oversteering like a Boss. Check your Tyre Pressures, make sure they are all correct.

[MB]

Way out of my league now Timbo mate! Do know that on our ageing little fleet of trols, OEM rubber does seem to last best as kindly suggested!


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[timbo2410]

No no I only assumed that a rubber substitute was better .. If I am wrong I stand corrected. I'm struggling to find any sort of "kit" as suggested by the mechanic today. I might pay a visit to our local Pedders and see what they have to say. Also, Tyrepower were the sub contractors to Ironman fitters. They were the ones who did all the aligning .. I might go in and ask for the angles and measurements so at least I can post here for advice.

[timbo2410]

and yes tyre pressures have been checked .. have also run anywhere from 32 up to 42 psi to see if it makes a difference .. and no it doesnt ..

[MudRunnerTD]

No no I only assumed that a rubber substitute was better .. If I am wrong I stand corrected. I'm struggling to find any sort of "kit" as suggested by the mechanic today. I might pay a visit to our local Pedders and see what they have to say. Also, Tyrepower were the sub contractors to Ironman fitters. They were the ones who did all the aligning .. I might go in and ask for the angles and measurements so at least I can post here for advice.

Rubber is best but the caster correction bushes are all nylon. you should really only need a slight adjustment? 2 degrees or so. Get your measurements and ask them how "Out" it was. They should be able to tell you the factory tollerance.

[timbo2410]

ok i will shoot into town this afternoon and ask tyrepower if they still have the specs or at least get them to check the specs .. I will post back asap

[timbo2410]

just an update, Tyrepower do have the specs from the original alignment (front and rear) and will re-check them next Tuesday morning. He did explain that yes the only way to correct the issue may be the castor kit as he checked the tyres and said there is no extra wear that bad now that would cause the tramming to be that bad. He did advise to get the correction kit from ARB or Opposite Lock here in town and not to go to the local Ironman centre though. So will post back here on Monday. Thanks for the help thus far people :-)

[MudRunnerTD]

just an update, Tyrepower do have the specs from the original alignment (front and rear) and will re-check them next Tuesday morning. He did explain that yes the only way to correct the issue may be the castor kit as he checked the tyres and said there is no extra wear that bad now that would cause the tramming to be that bad. He did advise to get the correction kit from ARB or Opposite Lock here in town and not to go to the local Ironman centre though. So will post back here on Monday. Thanks for the help thus far people :-)

It will just be bushes mate, I'd go ARB if i had to fit them. You will pay a premium for ARB to fit them but supply only they will be fine. get a couple of quotes to fit them if you supply them. that is where the money is. Any workshop with a 20T workshop press should be able to do the job.

[timbo2410]

yeah the Tyrepower chap explained that there is no way to correct castor issue without either bushes or new radial arm .. as explained here (so I don't think he was trying to BS me). He also went on to say (after I explained I had the lift kit done by Ironman franchise), that he himself would go to ARB and get the kit .. he wasn't really happy that I was sold a non centering damper either .. ??

[timbo2410]

yeah the Tyrepower chap explained that there is no way to correct castor issue without either bushes or new radial arm .. as explained here (so I don't think he was trying to BS me). He also went on to say (after I explained I had the lift kit done by Ironman franchise), that he himself would go to ARB and get the kit .. he wasn't really happy that I was sold a non centering damper either .. ??

[MudRunnerTD]

Im not a big fan of Return to Centre Steering (RTC) dampeners. Not really required on a 2" lift running 33s. The geometry should be perfect and the car should track straight. end of story. I dont have a RTC dampener on either of my cars. My GQ runs a 5" lift and 37s with No RTC Dampener.

[Bidja]

GU caster tolerance +/-1 deg from memory. Rule of thumb 1 deg caster correction per 1" of lift. U may not need them. Mine 2" lift bought 2 deg polyurethane caster correction bushes ($100 ebay specials), 90,000 ks ago still good. Do not go hard core off road but do my share of tracks and corrugations for sure (my dirt road to gate would sort them). Maybe just get a good whl alignment first up just to see results & go from there.

U could buy bushes (have in hand), go to good steering & suspension SME to check current geometry and fit bushes if req'd for 2"lift.

Local Koni distributor / alignment shop charge me $270 / 5 yrs ago for alignment($65) + fitting of bushes ($205). A bit of cost escalation expected for sure + $100 purchase for bushes.

Also, would not go RTC dampener, good HD do the job well.

[timbo2410]

hopefully the readings on Tuesday will give me a better idea as to what is going on .. I will post the results for everybody to look at and comment on. I did notice today that the tramming was slightly better after the service .. this didn't make sense as he didn't actually do anything. Then I took a tyre pressure reading and they have been pumped up to 42psi .. the tramming is still there and it is still very light at the front .. but it is slightly better.

[MudRunnerTD]

hopefully the readings on Tuesday will give me a better idea as to what is going on .. I will post the results for everybody to look at and comment on. I did notice today that the tramming was slightly better after the service .. this didn't make sense as he didn't actually do anything. Then I took a tyre pressure reading and they have been pumped up to 42psi .. the tramming is still there and it is still very light at the front .. but it is slightly better.

Try dropping the tyre pressure only in the rears to 35psi and go for a drive. 30psi even. This should fix it short term.

[timbo2410]

Nissan had them at the 30 front and 29 rear after their service .. was all over the road at 80kph .. I usually run them at around 37/38 psi .. but the 42 psi certainly helped the tramming today.

[MudRunnerTD]

Nissan had them at the 30 front and 29 rear after their service .. was all over the road at 80kph .. I usually run them at around 37/38 psi .. but the 42 psi certainly helped the tramming today.

Just to experiment. Drop the fronts to 30psi. This will change the caster by a couple of degrees and the problem should reduce again or go away.

[timbo2410]

Wouldnt dropping the front increase the castor error? If the effect of raising the suspension causes the front axle to be drawn further back (tilting it under the car) then wouldn't it be that the rear tyres needed to be lowered to have any effect on the castor? Or is it that regardless of the incline or decline the castor is out and raising or lowering the front or back will not effect the castor itself? Just trying to wrap my head around it is all :-)

[MudRunnerTD]

Wouldnt dropping the front increase the castor error? If the effect of raising the suspension causes the front axle to be drawn further back (tilting it under the car) then wouldn't it be that the rear tyres needed to be lowered to have any effect on the castor? Or is it that regardless of the incline or decline the castor is out and raising or lowering the front or back will not effect the castor itself? Just trying to wrap my head around it is all :-)

Indeed. Apologies. Run s lower pressure in the rears and go for a drive.

[timbo2410]

No problems, was trying to understand how it works .. will try and post back

[timbo2410]

Just went for a quick trip on the highway .. it's difficult to say really if it's any different .. possibly .. a bit ... it's still there for sure but probably no worse than a gust of sidewind. Put it this way I certainly dont want to take my eyes off the road .. nor drive with one hand ..

[MudRunnerTD]

Will be interested to see how far out it is and how much correction you need. It should feel planted.

[timbo2410]

yeah definitely not what I would call planted at all ..

[Brissieboy]

Just had work done this morning after new tyres and alignment and a resulting pull to the left resulting from an un-adjustable caster error.
Went to Pedders (at Geebung in Brisbane) with the report from the tyre mob. They look at the report but will not accept the results. A lot of alignments done by tyre places are less than ideal - mostly because of the quality or calibration of their alignment equipment. Pedders actually have top-shelf equipment and theirs is calibrated weekly! And these blokes really know their stuff.
Checked everything, fitted the appropriate caster correction kit and aligned things properly. Now drives dead straight.
I would strongly suggest that you spend the cash to have the experts do a check if you are having tramming problems, rather than simply playing with tyre pressures, etc. These thing will only mask the real problem.
BTW the job cost me considerably less that your original quote.

[MudRunnerTD]

Just had work done this morning after new tyres and alignment and a resulting pull to the left resulting from an un-adjustable caster error.
Went to Pedders (at Geebung in Brisbane) with the report from the tyre mob. They look at the report but will not accept the results. A lot of alignments done by tyre places are less than ideal - mostly because of the quality or calibration of their alignment equipment. Pedders actually have top-shelf equipment and theirs is calibrated weekly! And these blokes really know their stuff.
Checked everything, fitted the appropriate caster correction kit and aligned things properly. Now drives dead straight.
I would strongly suggest that you spend the cash to have the experts do a check if you are having tramming problems, rather than simply playing with tyre pressures, etc. These thing will only mask the real problem.
BTW the job cost me considerably less that your original quote.

I agree, an alignment at Pedders will be far better as it is their bread and Butter. Get the pros to do it for sure.

The suggestion of playing with the tyre pressures was purely for some experimentation over the weekend when no other avenue was available. Playing with Tyre pressure will never fix this, just mask the symptoms. Dropping the rear would give him the sensation of a caster change for the day to se how the change was.

I have driven a car with a new lift that tracked terribly. i was very concerned as it was my Dad's and i was delivering it to him. Had me worried. I pulled into a tyre place and found that 1 front tyre was 10psi lower than the rest of the car. Pump it up and transformed the car. So a Great place to start.

[timbo2410]

unfortunately there are no Pedders stores here that I am aware of (yes I have looked) .. there are the auto stores that sell Pedders parts and one that fits .. but they are not Pedders fitters .. closest we have is Opposite lock and ARB .. otherwise it's buying the parts (suggestions welcome) and getting others to fit them. I should know more tomorrow morning .. it will be interesting.

[MudRunnerTD]

unfortunately there are no Pedders stores here that I am aware of (yes I have looked) .. there are the auto stores that sell Pedders parts and one that fits .. but they are not Pedders fitters .. closest we have is Opposite lock and ARB .. otherwise it's buying the parts (suggestions welcome) and getting others to fit them. I should know more tomorrow morning .. it will be interesting.

Where are you located?

[timbo2410]

Southwest Western Australia

[MudRunnerTD]

Southwest Western Australia

Yeah ok, really any Suspension Specialist. Not really an ARB or alike, rather someone like Pedders?

Google search found this guy?

https://southwestauto.com.au/suspension/

but chase someone that specialises in suspension and steering.

[timbo2410]

Ok got some figures here:
Final Values:
Left = +0.22 degrees
Right = +0.53 degrees
Should be +3.5 degrees for both
So there ya have it ... Just a quick note .. the "2inch" lift by Ironman has a suggested end figure (total lift) of "BETWEEN" 50 and 75mm ..... just read it on the little note on the receipt ...

[timbo2410]

and just to give you an idea, I called our local Opposite Lock centre and to install "rubber" bush castor correction kit front and rear it will be $505 fitted. They say do NOT got for a 3 degree kit .. 2 degree will be enough. His explanation of what I have was superb .. the inability to drive with one hand on the wheel and the other resting on the window .... couldn't have put it better ..

[timbo2410]

And a few quick prices:
Local tyre and muffler centre: $400 but with polyurethane Old Man Emu that are 2 degrees
Local truck alignment centre: $375 but with polyurethane bushes that are 2.5 degrees

So the choices (if I want rubber) are from ARB but it will be 2 degree kit and get it fitted elsewhere
or a 2.5 degree kit but it will be polyurethane

Does the rear axle require any changes?

[Bidja]

Few points to consider, if you do the correction in line with your result(assuming to be accurate):



Left = +0.22 degrees
Right = +0.53 degrees
Should be +3.5 degrees for both

How old are your 2" lift coils (allow for sag over time). Is weight to remain same(bars/winch, drawes / load in back) etc.

Yes 2.5-3 deg would be correct based on result but IMO 2-2.5deg be OK, but your choice based on material selection. $375-400 looks OK, ask if it includes alignment check after fitting bushes. Maybe offer to supply the bushes to chosen installer if they do not carry them.
IMO, if she drove well before lift and you lifted 2", I would do 2 deg caster correction. Based on general rule 1 deg correction per inch of lift.

Rear axle is fine, only thing is make sure the brake lines can cope with drop of axles(front and rear). At least jack up each corner of chassis to achieve full extended shock length(whl off the ground) and make sure there is some slack in the flex brake hose/line. Most lift kits (eg: Dobinsons coils) come with spacer blocks to accommodate for lift. Ask the guys that supplied/fitted your coils.

The brake proportioning valve (lever/spring 90 deg position), might be OK. Do a search on topic.

[timbo2410]

The coils were fitted last October but I suspect that the heavier duty springs have a slightly higher lift than 2 inches and hence the more pronounced castor issue. I was advised not to go higher than 2 degrees (by ARB centre) and that coupled with the fact that they do the 2 degree kit made of rubber then I am inclined to buy the kit from them and get it fitted elsewhere like you said. The local truck alignment centre said flat out .. an hours work .. everywhere else has said 3 hours. Of course that's where the money lies in the total price. None of these prices were with any wheel alignment either. As the alignment was done in October and there doesn't appear to be anything wrong with it now, they have said not to bother doing one. If it does need to be done then put $88 on top.
I will certainly check out the brake lines along with the proportional valve. I did comment (prior to you guys mentioning it), that I had to hit the brakes recently and the wagon was very nose heavy .. probably the reason why.

[Bidja]

Spring rate refers to the amount of weight that is needed to compress a spring one inch. If the coil is rated 2" lift, be surprised if you gained more than 2" above stock within spec.
Alignment post fitting bushes was only to check the corrected caster. Sounds like U are sorted.

Did my 2" lift 5 yrs ago, did not change the Brake Positing Valve bracket to suit as had no real issues with nose diving. Maybe I just have not given the job much priority.....

[timbo2410]

that's just it though .. the heaviest 2 inch lift coils from Ironman come with the label 50 to 75mm .. so if it is on the higher side then that may be what is causing the issue. If it were just the 50mm then I might have been able to get away with it like others have. I was warned they would settle after a bit of use .. 10000 k's later and I dont think they are going to settle any more .. yeah I think the alignment is fine. Everything else is a non issue. No pulling left or right, no wobbles or vibration, steering wheel is centred ..

[timbo2410]

Well the good news is, I don't seem to have a brake proportional valve that is spring loaded or on a bracket .. mine appears to be controlled by the ABS ...

[Ben-e-boy]

and just to give you an idea, I called our local Opposite Lock centre and to install "rubber" bush castor correction kit front and rear it will be $505 fitted. They say do NOT got for a 3 degree kit .. 2 degree will be enough. His explanation of what I have was superb .. the inability to drive with one hand on the wheel and the other resting on the window .... couldn't have put it better ..

If you only have .2 and .5 degree of castor. 2 degrees will still put you out of tolerance. That is shit advice given by a 'Professional' You are still going to have adverse effects because your castor will still be out by 1 degree. Or 100% out of spec.

[timbo2410]

so ignore what the arb centre is saying .. and go for a 3 degree castor ..

[Bidja]

so ignore what the arb centre is saying .. and go for a 3 degree castor ..

Should identify what the caster angle spec range is for Patrol Hard Top (eg:Wagon) specific to your model, have read that GQ/GU spec max is 3.5° and have read there is a variation tolerance of +/- 1°. It could be that the caster angle range is between 1.5-3.5°. Different articles read state that the range is 1-3°.

So if these observations are correct: using 2° correction bushes would provide a corrected value of 2.22° (L) / 2.53° (R).

Info provided for purpose of discussion and enable you to seek clarification from SME.

Came across this link for RUBBER 2° CASTER CORRECTION BUSHES to suit Patrol for lift between 50-75mm from Ironman:

http://www.ironman4x4.com/products/suspension/caster-correction-803ee9ae-f1af-44fd-9a3c-dd35fa2ccee0/off-set-bushes-rubber/rubber-2-caster-correction-bushes-8f02214e-49c9-4140-8d2c-9b82269acd85

The alignment figures u posted are they current?

[timbo2410]

yes you are correct. The normal castor angle is +3.50 degrees.
And yes the current castor on mine is 0.22 (L) and 0.53 (R). Yes I did see the Ironman correction kit. But as I had so much trouble from the local Ironman centre, I just refused to go back to them. I could call to a Ironman supplier in the next town and see what they have to say. I found it interesting that the castor offset is the same rated lift (50-75mm) as listed on the springs that were installed and also that it is 2 degrees (as suggested by ARB) ...

[Bidja]

yes you are correct. The normal castor angle is +3.50 degrees.
And yes the current castor on mine is 0.22 (L) and 0.53 (R). Yes I did see the Ironman correction kit. But as I had so much trouble from the local Ironman centre, I just refused to go back to them. I could call to a Ironman supplier in the next town and see what they have to say. I found it interesting that the castor offset is the same rated lift (50-75mm) as listed on the springs that were installed and also that it is 2 degrees (as suggested by ARB) ...

Look they say suitable for 50-75mm as there will be an acceptable caster angle range(eg: say 1.5-3.5°). U need to clarify this, call Pedders, or a quality suspension/steering joint or maybe ARB or even Nissan Tech or refer to the veh manual.

Info only - I run 2" lift / 2° bushes, corrected @ 1.47(L) & 1.5(R) and all fine (5yrs)_33s M/T 17x8" steel rims 08 GU Wag (runs level F/R).

[timbo2410]

OK are you ready for this .. sit down before you read:
Ironman (the agent not a franchise): $400 for the 2 degree rubber kit fitted but may be more as it will take half a day to do the job! (they also wanted me to change the rear springs to shorter coils as it's easier and less labour intensive to do that than change the bushes)!!!!!!!!
Pedders (the agent not a franchise): $609 for the 2.5 degree kit fitted but the front bush will be rubber and rear will be polyurethane ($184 for the front and $62 for the rear radius bushes)
All say that it is not necessary to meet the +3.5 degree factory spec as their is an error allowance from the factory spec
Ironman franchise: $750 and half a days work
Pedders franchise: $735 and 3 hours work minimum

So there you have it .. So the long and short of it is .... I will buy a 2 degree rubber ARB set of bushes and take them through to the local truck alignment centre and get them fitted for $175 ...

[Ben-e-boy]

OK are you ready for this .. sit down before you read:
Ironman (the agent not a franchise): $400 for the 2 degree rubber kit fitted but may be more as it will take half a day to do the job! (they also wanted me to change the rear springs to shorter coils as it's easier and less labour intensive to do that than change the bushes)!!!!!!!!
Pedders (the agent not a franchise): $609 for the 2.5 degree kit fitted but the front bush will be rubber and rear will be polyurethane ($184 for the front and $62 for the rear radius bushes)
All say that it is not necessary to meet the +3.5 degree factory spec as their is an error allowance from the factory spec
Ironman franchise: $750 and half a days work
Pedders franchise: $735 and 3 hours work minimum

So there you have it .. So the long and short of it is .... I will buy a 2 degree rubber ARB set of bushes and take them through to the local truck alignment centre and get them fitted for $175 ...

So, for those prices why dont you get some drop boxes? That'll give you the castor you need and they're better than castor bushes

[Ben-e-boy]

so ignore what the arb centre is saying .. and go for a 3 degree castor ..

Yep. Just because they work a suspension shop doesn't mean they know squat about suspension dynamics. It means they can change a spring and shock.

[timbo2410]

are they better? I was told to steer clear of them .. and I didn't want to pay $600/700 ... for $375 have them done at the local truck centre ..

[Ben-e-boy]

are they better? I was told to steer clear of them .. and I didn't want to pay $600/700 ... for $375 have them done at the local truck centre ..

Who told you to steer clear of drop boxes? What are they basing that on?
Edit
Drop boxes are 400 from Superior Engineering. A fairly easy job to install

[MudRunnerTD]

Who told you to steer clear of drop boxes? What are they basing that on?
Edit
Drop boxes are 400 from Superior Engineering. A fairly easy job to install

On a 2" lift how much correction will drop boxes give? If have thought too much?

[Ben-e-boy]

On a 2" lift how much correction will drop boxes give? If have thought too much?

He needs a minimum of 3 degrees to bring it into spec. That in itself is the fact of the matter. The advertised amount of lift installed is irrelevant.
Also too much is better than too little.

[Bidja]

All say that it is not necessary to meet the +3.5 degree factory spec as their is an error allowance from the factory spec

Recon we all would appreciate there will be a tolerance, that controls the min/max angle for caster. Been stated in this thread.

Appreciate you ask your SMEs: what is the accepted industry caster angle variation (range)? and post up their advice.

[timbo2410]

I think that is the biggest question really. What is accepted .. sure the caster angle is supposed to be 3.5 degrees, but, if Nissan already have an allowance for +/- 1 degree for instance, then a 2 degree correction is going to be pretty much bang on. Not one out of the many installers that I spoke to suggested to go to a 3 degree kit, in fact just the opposite. I can go with the flow and install a 2 degree kit which has been recommended by ARB, Ironman, Opposite Lock, West Coast Suspensions and the local tyre shops. The only odd one out was Pedders who said they do a 2.5 degree kit but the rear bushes would be polyurethane.
So who has done this to their trol and used a 2, 2.5 or 3 inch correction kit? What is the feedback on those ?

[timbo2410]

if generally a 2 degree castor correction is accepted as solving the issue (with the castor figures I gave them), by the industries involved, then I can assume that there is a 1 degree error accepted

[MudRunnerTD]

Interesting. I have drop boxes on both my cars are they are awesome. Normally they kick in at a 3" lift but if the math is in your favour and you can fit drop boxes and stay at tolerance then that is 100% what I would be fitting.

Technically they are illegal but imo are by far the best possible correction option retaining the factory bushes.

The difference will blow your mind.

[timbo2410]

Personally i don't want to loose any more clearance under body. I'm still running stock alloys and tyres .. cant see me changing them for a long time

[MudRunnerTD]

Personally i don't want to loose any more clearance under body. I'm still running stock alloys and tyres .. cant see me changing them for a long time

The clearance loss is a bit of a myth mate. I have never been hung up on my drop boxes on either car. Been running them in the GUIV for over 12 years and 200,000 kms at least.

I can drive my GU with my Pinky mate. or on Cruise Control will track no hands for kms. (Not recommended...)

[timbo2410]

so on a drop box, how is the caster angle set if it is a fixed mount? If the box is, say, a 2 inch drop, but say my lift (due to the heavier springs) is, say 70mm, how is the extra angle compensated? Is there still a need for a castor correction kit?

[MudRunnerTD]

so on a drop box, how is the caster angle set if it is a fixed mount? If the box is, say, a 2 inch drop, but say my lift (due to the heavier springs) is, say 70mm, how is the extra angle compensated? Is there still a need for a castor correction kit?

No. The drop boxes are generally rated for 3 to 5 inch lift which is why I had not mentioned them. Basically your dropping the back of the radius arms down which will give you back your factory spec. With your lift you will likely end up with a little more caster rather than not enough. This will just mean it will track solid to the centre. Your steering will be slightly heavier but your power steering will sort that out and you will hardly notice and quickly forget.

Everything else remains the same. You retain the factory rubber bushes which are arguably the best possible option.

You will have to buy extended front sway bar links though.

[timbo2410]

Had an interesting chat with another tyre company today who deals with 4x4 mods. They had a Toyota L/Cruiser customer who wanted his wagon done to factory specs after a lift. After a lot of research they could not find anybody who could tell them the exact specs on the castor angle. They contacted Toyota who couldn't answer them. They got a hold of the local Toyota dealer who brought down 4 brand new (unregistered) cruiser wagons to see what the castor angle was from factory. Not one was the same and there was a 2 degree variation between them! Very interesting. The chap I spoke to (who actually owns a GU Patrol) has said to go down to the local truck suspension specialist (the cheapest price listed above), and to get him to do his own alignment testing and come up with the associated "rubber" kit. He has access to 2, 2.5, and 3 degree kits. The apparent problem with the Ironman springs is that they may be upwards of 70mm in lift height, and where a 50mm height may get away with no radius correction kit, it is widely known (by them), that people often have a problem after they are fitted. I would like to thank everybody that has offered advice on this forum :-) I intend to go down the castor correction path and see where it takes me. I will of course post back to let you all know how it goes. Won't be for a while though .. cheers everybody

[Bidja]

The chap I spoke to (who actually owns a GU Patrol) has said to go down to the local truck suspension specialist (the cheapest price listed above), and to get him to do his own alignment testing and come up with the associated "rubber" kit. He has access to 2, 2.5, and 3 degree kits.

Spot On mate