Outer Limits 4x4 Board

Hi all i have a question in relation to castor correction i fitted a 2 inch lift to my truck 92 gq and around town all was great but on the weekend i went for a bit of a freeway highway drive and whilst changing lanes at about 100 kmh the car swerves violently into the next lane (like i am some side swiping hell man )it seems to be after the tyres come into contact with the raised white line and it also seems to just follow any line or corrugation like i am on train tracks worse at greater speed, now for my question after fitting the lift kit i had a wheel alignment and i just dug out the invoice and had a look at the castor degree figures and this is what it states after the alignment (i cant figure out how to type the degree symbol so the full stop represents that) left -0.06 right -1.27
would two degree bushes be enough to correct this or should i look to another soloution

and i also must appoligise for my lack of punctuation something else i must learn before i die
any help truly appreciated
warm regards simon

Did you get new or wider tyres at the same time

hi stool no same tyres i had on before it became the terrifying sled of death
warm regards simon

Those castor readings are a bit of a worry, negative castor is bad, but, the main worry is the difference between the two sides. I'd be looking for bent front end components to start with on the right hand side. The left hand side is about right as far as a 2" lift goes so two degree bushes would be fine. Castor bushes tend to limit front end flex though compared to the factory rubber bushes.

Cheers, Jeff.

I have the same problem (100%)

I have a swb gq with 3" dobison lift and mine does the exact same thing scares the shit out of me and a pain in the a$$..

I fitted 3.5degree castor bushs those adjustable iron man ones.

Might get a wheel alignment and wheel balance and see what the go is..

I fitted 33" MT MTZ's from 31" a/t.

Also has vibration that shakes the cab at low speed 10 - 40 kms then drives out of it at higher speed.


(Sorry about the hijack just thought instead of starting a new thread)

Cheers

Rick.

I had the same problem when my castor was at about 0 deg. Bazzle recommended at the time to adjust the toe in to neutral (i.e. 0) which fixed most of the problem. Worth a try IMO.

Cheers
Joachim

JBE wrote:I had the same problem when my castor was at about 0 deg. Bazzle recommended at the time to adjust the toe in to neutral (i.e. 0) which fixed most of the problem. Worth a try IMO.

Cheers
Joachim

Sorry to be a pain in the ass but what does all that mean i didn't understand it..

Cheers

Rick.

The front wheels on rear wheel driven cars and fourbies point slightly inwards to the front of the vehicle (positive toe in) to achieve directional stability (castor and camber contribute to the directional stability as well).
Neutral toe in simply means that your front wheels are exactly parallel (horizontal axis).
If your castor is around 0 deg and your toe in is still factory setting, the vehicle tends to follow grooves on the road surface (I can't remember what it's called, but there is a term for it). I learned the hard way that this can lead to erratic lane changes, especially at highway speeds.
Adjusting the toe in to neutral can soften this behaviour and make the vehicle more controllable. I just went to the alignment shop and asked them to adjust the toe in to 0.

Hope this explains it.
Cheers
Joachim

JBE wrote:The front wheels on rear wheel driven cars and fourbies point slightly inwards to the front of the vehicle (positive toe in) to achieve directional stability (castor and camber contribute to the directional stability as well).
Neutral toe in simply means that your front wheels are exactly parallel (horizontal axis).
If your castor is around 0 deg and your toe in is still factory setting, the vehicle tends to follow grooves on the road surface (I can't remember what it's called, but there is a term for it). I learned the hard way that this can lead to erratic lane changes, especially at highway speeds.
Adjusting the toe in to neutral can soften this behaviour and make the vehicle more controllable. I just went to the alignment shop and asked them to adjust the toe in to 0.

Hope this explains it.
Cheers
Joachim

Cheers mate

Will ask this when i take my car in

Rick.

thanks for the replys all must admit dak now i am a little worried about what could be possibly bent and i will look at the toe in thing jbe, and also mulisha did the castor correction bushes not help at all ? please let me know if you get your toe in looked at before me as to how that goes for you i imagine in that beast of yours it is a lot more of a scary handful than my old girl
warm regards simon

JBE wrote:vehicle tends to follow grooves on the road surface (I can't remember what it's called, but there is a term for it)

i think the term is pants filling lane changing
warm regards simon

I beleive the term is tramlining
Mulisha try adjusting the upper arms out so the diff rotates back about 18mm on std arm lenth, should fix the vibration

I wouldnt be concerned with the different readings, Id be very suprised to find a 4wd with exact readings either side.

azzad wrote:I wouldnt be concerned with the different readings, Id be very suprised to find a 4wd with exact readings either side.

Yes true, a small difference is normal and acceptable, but the readings he has given are hugely different side to side, half a degree max is acceptable but not 1 degree 20. I do cert work alignments and a vehicle with differences like that I would reject.

Cheers, Jeff.

hi dak and others just a quick question in relation to my castor measurements what should i look at checking to correct this difference nothing appears out of the ordinary under the car it looks as though it spent most of its time on bitumen in its past life could any worn components maybe bushes cause this dilema i haven't had this car long and i kid you not i have already shelled out thousands
the other measurements for test were
k.p.i 10. left + 7.50 right +6.22
camber left-0.24 right +1.15
individual toe left +2.5mm right -2.6mm
total toe -0.1mm
setback +0.00
warm regards simon

Sorry dude, it gets worse, those camber readings are diabolical. Bent or twisted diff. It's hard to say. Or, you might have a shop that doesn't calibrate their aligner and, or, someone that doesn't know what they are doing did the alignment, check for buckled rims, although the guy doing the alignment should of done a run-out compensation. But I'm picking bent bits, could be the housing itself or the hub but it all points to the right hand side.

Cheers, Jeff.

Those readings are shocking!

iirc factory specs for gq castor are around 2.8 degrees. Negative castor is very bad (think of a shopping trolley wheel, positive castor and the wheel is behind the vertical axle line, negative and the wheel is in front - imagine pushing a shopping trolley like that!)

Patrols generally get away with a 2inch lift and not needing castor correction too badly so something is very wrong. It wouldnt surprise me if the wheel alignment place haven't calibrated their machine, therefore adjusting toe all wrong and supplying you with incorrect castor readings.

Where are you from? someone may recommend a better alignment joint.

Also try rotating your tyres front to back, as they often wear funny and when you lift it can cause weird pulling effects.

thanks dak i truly appreciate your input on my problem i think i will take it to another place and have them have a look at this point i am still trying to be positive as before the lift it drove pretty well i dont want to name the place that i had the alignment done just yet as it may be correct although i will say it was one that puts out catalogues on a monthly basis so that sort of deal cars everywhere with heaps of people waiting and young kids doing the majority of the work and cossie to answer your question i am in ringwood (melbourne eastern suburbs) so yes if any one can recommend somewhere that would be great
warm regards simon

something that just came to mind is i remember having a flat front driver side tyre (slow leak ) before dropping off the car and now wonder if this could have affected the alignment i just assumed they would factor for theses things

Try rotating your tyres first. Failing that take it to Bob Jane in Moorabbin, ask for a guy named Darren, he's been doing alignments for over 20 years and what he doesn't know about it isn't worth knowing, their machine is accurate too.

ive got bad vibrations and handling in my swb after fitting 2inch lift. its very bad. i spoke to a good place in moorooka brissy, and they said that the vibrations would stop by correcting castor, but wouldnt help steering! then i spoke to another place and they said the caster bushes (or whatever) would help steering and a gearbox packer kit would fix vibrations. now im not sure what is what.

simeys wrote:thanks dak i truly appreciate your input on my problem i think i will take it to another place and have them have a look at this point i am still trying to be positive as before the lift it drove pretty well i dont want to name the place that i had the alignment done just yet as it may be correct although i will say it was one that puts out catalogues on a monthly basis so that sort of deal cars everywhere with heaps of people waiting and young kids doing the majority of the work and cossie to answer your question i am in ringwood (melbourne eastern suburbs) so yes if any one can recommend somewhere that would be great
warm regards simon

something that just came to mind is i remember having a flat front driver side tyre (slow leak ) before dropping off the car and now wonder if this could have affected the alignment i just assumed they would factor for theses things

Part of doing a wheel alignment is checking correct tyre pressure before you even start, so if they did it properly, then it shouldnt be effecting the readings.

Layto....

well i thought i'd add my 2 cents
my truck,98 gu has the following,
6 months old 3 inch lift
6 month old cooper st's 33's/12.5
new adjustable drag link
new wheel bearings
new swivel hub bearings
new steering dampener
new 3 deg bushes and just got my tires balanced and a wheel alignment done last week at pedders and my rig still tends to bump steer and waver over the road a little bit.Im running out of idears wat the hells happening.
i'l have to dig up my readings and hear some comments on them.
i'v spoke to afew people who have the same size tires as mine on standard 4wd's and they said the coopers tended to "drag" them all over the road! if only they made desert duelers in 33's..lol
now time to dig up those readings.

Have just put 35 inch tyres on my GQ which has 2inch springs 30mm coil spacers and 2 inch body lift. Following wheel alignment readings were as follows:-

Front Left Side 0.56 negative
Front Right Side 0.76 negative
Overall .5 degree negative

What castor correction would correct this say 3 inch and which is better castor bushes or radius arms
cheers, Mick