Bent chassis

unko84

Active Member
#1
I think I have an bent chassis as there are a 7 to 9 mm difference in length from front to back the drivers side is shorter. Mesurment was taken from hub to hub All Bush's are fine to look at and have no movement.

Is the first step to to get a wheel elinement or go to pedders suspension and get them to cheak it out

Btw it's a gu patrol when on tour it's 4t (been over weigh bridge when loaded)

Is there a place in adelaide what does this kind of stuff
 

CaptainBanana

Well-Known Member
#2
I think I have an bent chassis as there are a 7 to 9 mm difference in length from front to back the drivers side is shorter. Mesurment was taken from hub to hub All Bush's are fine to look at and have no movement.

Is the first step to to get a wheel elinement or go to pedders suspension and get them to cheak it out

Btw it's a gu patrol when on tour it's 4t (been over weigh bridge when loaded)

Is there a place in adelaide what does this kind of stuff
Not a really common vehicle for bent chassis although you're pretty heavy, I. Presume 4t with a van on the back?

Check rear upper spring mounts for cracking and check trailing arms on the diff and their mounting points for a start.

Any decent workshop especially panel shop can tell you where it's coming from.
 

discomatt

Well-Known Member
#3
I doubt that much is in the chassis, it would have some very noticeable kinks if it was and the door and guard gaps would be all over the shop.
Put it up on 4 good jack stands on level ground, then get under it with a mate and a tape measure and start taking measurements.
Each side of the chassis, length, across and diagonal , measure points on the chassis to diff mounts, diff center and ends.
You will soon get a picture of where the issue is
PS, I was a panel beater for 14 years, 14 years I will never get back...
 

Outrage

4x4 Earth Contributer
#4
When speaking with a mechanic that also fabricates/fits barwork, his comment was for the majority of patrols he's worked with, the chassis is typically bent/twisted in some minor way, as something doesn't line up properly when he tries fitting bullbars, etc. Agree that it is rare for 'significant' deformation though.

This may help anyway.
GU chassis dimensions.png
 

mac_man_luke

Well-Known Member
#6
My thoughts are, get under it have a measure and looks to see if you can see anything obvious.
If that does not show anything, maybe a wheel alignment specialist would be worth a look
or go the next step and get someone who can measure the chassis properly (someone like SA Chassis and suspension)
 

dno67

Well-Known Member
#7
Check the length of your rear control rods, IMO i would loose to much
sleep over it. Some holdens were built like that. lol
 

unko84

Active Member
#8
Not a really common vehicle for bent chassis although you're pretty heavy, I. Presume 4t with a van on the back?

Check rear upper spring mounts for cracking and check trailing arms on the diff and their mounting points for a start.

Any decent workshop especially panel shop can tell you where it's coming from.
I wish the patrol was 4t without towing, the weight is about 3.3t with just full fuel tanks, buy the time you add 100l of water, fill the fridge add food and camping gear and spares
 
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unko84

Active Member
#9
Check the length of your rear control rods, IMO i would loose to much
sleep over it. Some holdens were built like that. lol
I wouldn't care to much but it torque steers when you get on the gas and off, I have a mild tune(28psi, 19/1 AFR,) it shouldnt change things tho. It has pretty much full superior gear running gear underneath.
 

dno67

Well-Known Member
#10
I wouldn't care to much but it torque steers when you get on the gas and off, I have a mild tune(28psi, 19/1 AFR,) it shouldnt change things tho. It has pretty much full superior gear running gear underneath.
How old are (all)the bushes ? Just because they look good and don't appear to have any wear dosen't mean there not damaged and could be contributing to the torque steering. 28psi will be adding a fair load to most drive line components and will certainly shorten the serviceability of your bushes if you've got a heavy right boot.
 

unko84

Active Member
#11
I have had replaced the lower control arms in the last 15 k, ive put a bar to f and b panrod bushes and no movement, ive sent to off to the mechanics
 

dno67

Well-Known Member
#12
I'd measure both rear control arms, also dose it have caster correction bushes
fitted to the front control arms, these may have also effect the measurements
if not fitted the same to both control arms.
 
#13
i found with my old gq tb42e turbo that even with brand new genuine bushes it got a decent amount of torque steer when on or off throttle, just put it down to the fact that the suspension in these rigs was designed to flex over obstacles not to put large amounts of power to the ground
 

unko84

Active Member
#14
I'd measure both rear control arms, also dose it have caster correction bushes
fitted to the front control arms, these may have also effect the measurements
if not fitted the same to both control arms.
didnt think if that I cheeked the radius arm spacers but not the caster, cheers
 
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