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cutting cross member for lift
Posted: Wed Feb 10, 2010 9:58 pm
by drafter01
hey guys, i am now running a 6" lift on a gu ute, with 8" procomp shox at the rear, and i seem to have a problem that when it flexes that the tail shaft hits on the cross member, ive already turned the tailshaft around but it still hits. what do u reckon bout cutting a V in the cross member and welding plates in where i cut it on the angle and then a 30mm x 30mm angle bar under neith for support, let me know thanx,,,
Posted: Thu Feb 11, 2010 6:28 am
by chpd80
I have seen a crossmember cut and plated to clear exhaust etc, so yes it definately can be done,
but you have to ask yourself why your going down the path of such a big lift and potentially creating more problems.
"For every 1 modification you create 10 problems." so you want to make sure that the mod you are doing is going to be worth the trouble.
It may be easier (now and in the long run if you sell the vehicle or get pulled over the pits) to fit limiting straps to stop the drive shaft hitting.
crossmember
Posted: Thu Feb 11, 2010 6:43 am
by WelchyGQ
check out superior engineerings website there is a guide on how to do it on there.
Cheers,
Welchy
Posted: Thu Feb 11, 2010 7:36 am
by ludacris
Just make sure that you do not modify the vehicle to a point of no return.
Limiting straps would be a better choice or find an engineer who will approve the cutting and modifying of the chasis to clear the tailshaft.
Cris
Posted: Thu Feb 11, 2010 7:54 am
by steel
Cutting the Xmember is not " modifying the vehicle to a point of no return".
If it doesn't work out, then just bolt in another Xmember.
I made a whole new Xmember for mine from Bisalloy plate, though i was lifting my drivetrain, but it solved all clearance problems between Xmember and driveshafts.
xmember
Posted: Thu Feb 11, 2010 8:39 am
by purplebus
i had mine cut approx 2yrs ago. no problems at all after heaps of abuse. as you say you can just bolt another one in if need be its only 8 bolts and 2 nuts.
Posted: Thu Feb 11, 2010 9:19 am
by bogged
ludacris wrote:Just make sure that you do not modify the vehicle to a point of no return.
Limiting straps would be a better choice or find an engineer who will approve the cutting and modifying of the chasis to clear the tailshaft.
why worry bout engineering that, the 6in lift and 35+'s are a give away before ya get to the t/shaft!
Posted: Thu Feb 11, 2010 9:52 am
by ludacris
bogged wrote:ludacris wrote:Just make sure that you do not modify the vehicle to a point of no return.
Limiting straps would be a better choice or find an engineer who will approve the cutting and modifying of the chasis to clear the tailshaft.
why worry bout engineering that, the 6in lift and 35+'s are a give away before ya get to the t/shaft!
Sorry as I assume he was talking about the rear tailshaft as I have never heard of the front tailshaft getting swapped around to clear.
If you are talking about the front cross member go ahead and cut as it has been done 1000 of times with no ill effect.
With the engineering side of things you can easily swap the standard suspension in to sell the vehicle but modifying the chasis is going to be a pita to return back to factory specs to sell or go over the pits hens engineering plate for modifying the chasis.
Cris
Posted: Thu Feb 11, 2010 7:49 pm
by YNOT
If he is talking about the rear tailshaft hitting, a high pinion rear diff is another option.
Tony
Posted: Thu Feb 11, 2010 9:47 pm
by macneil
rofl why the hel would you want a 6" lift.. would handle like poo look like poo and be a cop magnet, Not to mention there is no need for a lift that big... if you want flex get a set of 3" flexi coils.. or a custom a frame set up in the rear with coil overs...
still good
Posted: Thu Feb 11, 2010 9:51 pm
by drafter01
well actually id drives really nice still, handle good, and goes hard, and i like the lift because well, y not,, its different,,, and i trimmed the rear cross member to allow for the 8'' shox that i will be running...
just heat it up n tap it in work fine on mine for yrs
Posted: Fri Feb 12, 2010 1:55 am
by satman
ok
Posted: Mon Feb 15, 2010 9:35 am
by steve patrol
Had to cut and weld both of mine. Used 100mm x 3.2mm steel tube to weld in place. Did this over a year ago, there has been no drama with it cracking or warping, just take your time when welding them in, dont let it heat up too much and dont let them cool too quick.
As for a big lift, its all to do with the nut behind the wheel, mine handles like a dream (in my opinion and the coppa that pulled me over 2 months ago and took it for a spin...) 6in sus 2in body lift no sway bars, loves 140kph down the freeway but still getting hung up on rocks. For some reason Im thinking I should have gone the 8in lift for the places I wheel or take the easier lines... Each do there own, just dont be a pony...
my 2c
Posted: Mon Feb 15, 2010 12:20 pm
by crankycruiser
xmember
Posted: Mon Feb 15, 2010 7:02 pm
by paul44b
I still think he means the rear tailshaft rubbing, not the front...And macneil, each to their own, different people do different things in their car, I have had a 6" lift in all my cars, they still drag their ass around which is where lockers and a winch come into play, and I have never been pulled over by the cops....
Posted: Mon Feb 15, 2010 7:24 pm
by ludacris
Yes he was talking about the rear tailshaft.
Cris
Posted: Tue Feb 16, 2010 9:27 am
by SuperiorEngineering
Re: still good
Posted: Tue Feb 16, 2010 11:01 am
by gu town
drafter01 wrote:well actually id drives really nice still, handle good, and goes hard, and i like the lift because well, y not,, its different,,, and i trimmed the rear cross member to allow for the 8'' shox that i will be running...
no it's not.
if its the front. when i had a 6in lift i just heated the gearbox X-member up and bashed it down... doesnt need much.
if its the rear.... i've never heard of it hitting after flipping the tailshaft.
Re: still good
Posted: Tue Feb 16, 2010 12:10 pm
by 351ciofgrunt
gu town wrote:
if its the front. when i had a 6in lift i just heated the gearbox X-member up and bashed it down... doesnt need much.
if its the rear.... i've never heard of it hitting after flipping the tailshaft.
Yes the rear does. I have a GQ with 4inch springs and with the tailshaft flipped i've still only got 15mm clearance to the crossmember at ride height. I'd imagine with a 6inch lift there would definitely be clearance issues.
Posted: Tue Feb 16, 2010 1:50 pm
by SuperiorEngineering
A true 6 inch lift will hit without doubt. Thats front and back.
Their are a lot of kits out their advertised as 6 inch kits but are hardly able to make it to a true 4 inch in lift.
We have had to cut the crossmembers on our 4-5 inch lifts at times, you dont just check when it is on level ground but also when the vehicle is on a hoist.
Posted: Tue Feb 16, 2010 9:33 pm
by drafter01
hey, i got the lift from superior the 4-5 lift, and then through 2 " spacers in it, so after the bit of sag i estimate 6", its fairly huge, and ive cut the front and rear cross member, i welded bits of steel in to replace the bits i cut out,, dont think its as professional as sum of ur pics, but i reeforced the rear one with sum 25 x 25 angle under it, and i barly cut the front one at all, i was also wondering if i got a 10mm plate laser cut to fit the exact rear tailshaft at the diff would it make it better, as in clost the extension up on the tailshaft,,,
Posted: Tue Feb 16, 2010 10:38 pm
by hiy6o
When mine had a 7" lift I cut the rear cross member out rotated it so the bend towards the rear was now towards the bottom , sleeved it internally and rewelded into chasis even drilled the three holes back on the bottom side would take an expert on patrols to spot it . (i put a prop in between the rails thinking they might spring in when the crossmember came out , didn't move at all.)
Posted: Wed Feb 17, 2010 7:24 am
by SuperiorEngineering
drafter01 wrote:hey, i got the lift from superior the 4-5 lift, and then through 2 " spacers in it, so after the bit of sag i estimate 6", its fairly huge, and ive cut the front and rear cross member, i welded bits of steel in to replace the bits i cut out,, dont think its as professional as sum of ur pics, but i reeforced the rear one with sum 25 x 25 angle under it, and i barly cut the front one at all, i was also wondering if i got a 10mm plate laser cut to fit the exact rear tailshaft at the diff would it make it better, as in clost the extension up on the tailshaft,,,
yes, you are basicly making a tailshaft spacer.
wondering
Posted: Wed Feb 17, 2010 7:32 pm
by drafter01
so it is possible to make a tail shaft spacer, do u guys at superior do them, or have ever done them before,,,
Re: wondering
Posted: Wed Feb 17, 2010 10:17 pm
by vanbox
drafter01 wrote:so it is possible to make a tail shaft spacer, do u guys at superior do them, or have ever done them before,,,
http://www.superiorengineering.com.au/a ... er&x=0&y=0
Posted: Thu Feb 18, 2010 8:27 pm
by Diepawsey
when i was running a 6inch in my gu (biggest mistake of my life) i left 3inch extended sway bars in to hold the diff from falling down to far and hitting. another option is a restaining strap at the center of the diff to hold it from going to far down, in theory this should still allow great flex both sides but prevent downwards diff travel that causes the rubbing
Re
Posted: Fri Feb 19, 2010 10:33 am
by morewheeldrive
I'm running 6 inch lift and I had the same issue with rear xmember aswell as that when I flipped it round the slip joint didn't like turning opposite direction after turning in the stock rotation for 230k. I tack welded a brace between the chassis rails then cut the xmember out and chopped and welded in four 90 degree bends of the same size OD pipe affectivly turning the straight xmember into a sort of u shape that ran over the top of the tail shaft close to the body. I tig welded it so it's strong and I'm thinking that xmember mainly takes twisting strain so I wasn't too worried. Haven't had any problems 2 years on and my tail shaft still spins the right way. And if I do decide to go long arms and coilovers later I don't have to worry bout that xmember. Ps. As far as lift goes who cares how high his suspension is. It's his truck and he wasn't asking for an opinion on what anyone thought of 6inch lift. He was asking about a problem that he would like to fix. Doesn't matter if it's 1 inch or 10 inch, each to they're own.
Posted: Fri Feb 19, 2010 11:37 pm
by Southern Cross 4x4
SuperiorEngineering wrote:A true 6 inch lift will hit without doubt. check when it is on level ground but also when the vehicle is on a hoist.
x2 Check maximum suspension droop as this is most critical about modin ya crossmembers.