legalitys of modifying shock towers, is there any?

[shorty_f0rty]

hey y'all..

I was just thinking about some of the mods I haven't done yet and one is the F250 Front Shock towers mod for the 40 series to allow longer shocks to be fitted (although i need to investigate it more to find out exactly what is required).

What are the legalitys of changing this from stock towers? I haven't seen anything specific to this that I have read in the Qld DOT modification guide.. and its not really modifying the height of a vehicle.. just allowing more compression/flex at the front so im not sure.

I know this is a common mod for lux's in replacing the stock towers with shock hoops, so would this be in the same ball park for the 40 shock tower mods?

The only issues I can think of is having to weld to the chassis which would require an engineer cert at least i assume..

any info would be appreciated.

[bru21]

the following is technically speaking, but only a absolute wanker would pull you over for this, or a really smart lawer in a crash.

you are not allowed to change (raise / lower) the suspension by more than a third of its original bumpstop height. i guess legally, adjusting the towers will effect the suspension height and travel when cornering etc, even though the static ride height remains unchanged. by moving the shock up and 1" increases the change by 2" as the shaft can pull out a further 1" and the piston can move in the tube by a further inch. so technically what you want to do will affect this by more than a third of original, as you would not bother unless you made a significant difference.

i don't think you need a engineers cert for the welding, however the rules state that only material of up to double the thickness (no greater) of the weld site may be welded on in strucural areas. we are building a 7 replica, that is how i know this.

hope this helps.

[shorty_f0rty]

wow full on!

cheers for the info..

threads I have read on ih8mud (http://forum.ih8mud.com/showthread.php?t=48041) make it look like i could get away with not having to weld..

interesting point of view with the increase in shock tower height (potentialy 2-3" increase) so i'll keep it in mind.

[Slayer]

the following is technically speaking, but only a absolute wanker would pull you over for this, or a really smart lawer in a crash.

you are not allowed to change (raise / lower) the suspension by more than a third of its original bumpstop height. i guess legally, adjusting the towers will effect the suspension height and travel when cornering etc, even though the static ride height remains unchanged. by moving the shock up and 1" increases the change by 2" as the shaft can pull out a further 1" and the piston can move in the tube by a further inch. so technically what you want to do will affect this by more than a third of original, as you would not bother unless you made a significant difference.

i don't think you need a engineers cert for the welding, however the rules state that only material of up to double the thickness (no greater) of the weld site may be welded on in strucural areas. we are building a 7 replica, that is how i know this.

hope this helps.

what do shocks and bump stops have to do with each other???

truck should have bump stops between the axle and the chasis, not rely on shocks

[Tojo]

are you sure you really need to do this? If you fit shocks 2-3" longer don't forget that collapsed they will also be longer. And you don't want to use your shock as a bump stop or you'll break it. So then you might need to lower your bump stops. And if you do that you have just reduced your wheel travel. I would suggest unbolting your shocks and measuring the extended and collapsed lenghths of the standard mounts. Then check some measurements of various shocks and see if any match.

[bad_religion_au]

are you sure you really need to do this? If you fit shocks 2-3" longer don't forget that collapsed they will also be longer. And you don't want to use your shock as a bump stop or you'll break it. So then you might need to lower your bump stops. And if you do that you have just reduced your wheel travel. I would suggest unbolting your shocks and measuring the extended and collapsed lenghths of the standard mounts. Then check some measurements of various shocks and see if any match.

ahhh that's why he's adding the longer shock mounts// so that when the longer shock goes in it will bottom out at about the same point as the original shock (probably after the axle and bump stop have met

[bru21]

bump stop and shocks are un related physically in what i am saying but are when the dot comes into play. raised shock upper mounts will increase the possible travel, increasing the bump stop clearence by more than 1/3 when cornering.

[shorty_f0rty]

I was just wondering about the mod as it seams popular in the us.. i guess there is all that other stuff to think about when doing it but I haven't really got that far yet..

its just another pipe dream at the momente till my next paycheck.. and the ever quest for more flex..

[Slayer]

bump stop and shocks are un related physically in what i am saying but are when the dot comes into play. raised shock upper mounts will increase the possible travel, increasing the bump stop clearence by more than 1/3 when cornering.

so does this mean longer shocks are not dot approved either, becuase they will increase travel??

id like to see a dot man hangin on a rope measurin my bump stop clearance while turnin a corner...
seriously tho i have to question how corect this is, i recon a stock standard 80 series body rolls on a long fast corner enough to open up bumpstop distance more than that... .. there is more travel from ride hight to full extension in a standard shock than that of 1/3 of bumpstop clearance...
anyways ymmv