shackle reversals

[fatassgq]

Hey there all.
I was just wondering if anyone has had any (real) experience with shackle reversals on sua trucks. I have just had one done on my truck (75 series trayback) and while I am extremely happy with the job and how the truck drives etc I would like any comments you have. The only gremlin we are yet to sort out is the steering. We moved the axle forward a true 60mm (20mm forward on mounts and fliped springs around 40mm gain) so draglink and tie rod are very close. Thinking of moving steering box forward 30mm or so(as far as possible) I have been told you can get a 60series steering box mounted with the pitman arm going toward the front of the truck but is a lot of stuffing around. Will the steering cause dramas off road?
Thanks for any constructive comments in advance.

[dumbdunce]

60 series box would put the draglink a long way forward. as long as the draglink and tierod don't clash/bind on suspension compression it should be ok. the axle movement is close to vertical with flattish springs. get it on a ramp or on some rocks and flex it up, see how it goes before you panic and start hacking into it. if it is close maybe slip the axle back the 20mm allowed by the perches - less than an inch won't take much out of your approach and is kinder to the slip joint in the prop shaft.

[fatassgq]

Thanks Dumbdunce,
Yes I thought that changing steering boxes would be a drama I could maybe do without (wallet will thank me too!) I have to get hold of a front tailshaft asap and then I will see how it all goes. It definitely transmits a lot less bumps etc back through the steering wheel now. Not to mention a much better looking front approach. I can't wait to take it offroad.
What do you mean by taking the axle back 20mm allowed by the perches?
Do you redrill the perch? As far as driveshaft and slip yoke etc goes I have to get a whole new shaft made up cause my old one was no way long enough.

I hope to have some pics on day soon so I can show and tell anyone interested in this conversion. It certainly seems positive on road so far...

[dumbdunce]

I may have misunderstood your 20mm - I thought you had redrilled the perches, but now I think you have moved the front hangers down and 20mm forward, right?

so in that case yes you can redrill the perches and slip the axle back up to an inch - for only 40mm you could use a tailshaft spacer without drama - with the SOA on a 75 I recently did the tailshaft only needed to be about 60mm longer (made a spacer out of old diff flanges), be careful you don't make it too long or the slip joint will bind on full suspension compression.

cheers

Brian

[fatassgq]

Thanks again dd
I will have to do a bit of measuring this w e and see just what I am up for. The only other thing I am concerned about is space for the 35s on compression (as it is now going backwards). I was hoping to not have to hack body work. I guess I will just have to wait and see. The front springs in my truck are pretty arched but I have superior shackles on it. There are not many springs in the pack (seem to only just hold the old diesel up!) and the ride is actually very soft.Rear has 8 inch longer springs with orbit eyes in the custom fixed eyes with superior shackles on the rear. Plus ladder bar, strap cust shock mounts etc. Yeah we did move the front hangers forward 20mm and down about 50 to help caster etc. The gain is only minimal on approach there but the tires have come a long way forward and I can hit things without fear of shackle damage (inversion etc) and the tires will grab the obstacle a lot sooner. I think my orginal shaft was just too short because with the old set up it was getting enough flex to compress the shaft, and I soon noticed it was pushing my gearbox and engine backwards! So at some stage it was shortened. Now I need a longer one!
Sincere thanks for you input dd any more info you have would be greatly appreciated. My truck is actually on superiorengineering.com.au website if interested, under before and after shots but have yet to update pics they are a bit older. Cant wait to see how the old girl goes offroad now with the new setup. Does anyone know if SR's on sprung under trucks make any difference to articulation or in general. As I said it seems to drive beautifully and I have not even had an alignment as yet....

[MUSS]

fat arse... you truck flexs fawkin awesome man been thinkin about doin shackel reversal to my middy too plus if it moves the front diff foward 2 inches like you said i wood be able to fit 35's under the front guard with out haven to do any panel beetin or SOA.... just a 2 inch body lift shood be sweet.. correct me if im wrong dumbdunce????

[fatassgq]

Hey Jake,
The shackle reversal is a reasonably big job for what you get (not too bad really) It just depends on how far you want to go in future I spose. I certainly am happy so far the car drives real nice.
As far as I was concerned:
PRO: Better approach, can fit bigger tyres, less chance of hanging a shackle up on stuff, lot nicer to drive over bumps(diff can go back instead of trying to push against it,extra articulation (maybe), and it's something different!!!
CON: Nose dives a bit more under brakes due to geometry of things(get used to it), steering link positions, illegal?, fair amount of work involved plus whatever else anyone can tell ya either way. (IN your case you will have to weigh up how much flex you get and see how big you could go on tires. Remember diff will be going back slightly (depending on arch of springs etc) under compression.
At the end of the day I am stoked. It looks like it will be a much nicer ride over the ruff stuff and I may even pick up a little flex. I can fit bigger tires when $ permits and I have not seen too many like mine around.
If you want any info ring the guys at superior or post here and I may be able to help plus many others I am sure.
catch ya

[dumbdunce]

yeah jake a 70/73/75 will fit 35's with 2" suspension + 2" body lift. 33's just fit with 2" suspension only.

on the back 12.5" tyres will rub on the inside of the fender wells on full articulation - use rims with around an inch negative offset, any more and the front will rub badly on full lock (this is assuming no shackle reversal).

if you go SOA with 2" springs and 2 - 3" body lift, 44's will fit fairly easily *grins*

[dumbdunce]

yeah jake a 70/73/75 will fit 35's with 2" suspension + 2" body lift. 33's just fit with 2" suspension only.

on the back 12.5" tyres will rub on the inside of the fender wells on full articulation - use rims with around an inch negative offset, any more and the front will rub badly on full lock (this is assuming no shackle reversal).

if you go SOA with 2" springs and 2 - 3" body lift, 44's will fit fairly easily *grins*

[MUSS]

yeah jake a 70/73/75 will fit 35's with 2" suspension + 2" body lift. 33's just fit with 2" suspension only.

on the back 12.5" tyres will rub on the inside of the fender wells on full articulation - use rims with around an inch negative offset, any more and the front will rub badly on full lock (this is assuming no shackle reversal).

if you go SOA with 2" springs and 2 - 3" body lift, 44's will fit fairly easily *grins*

hmmm i was just gonna bbuy a pair of 1inch wheel spacers to put on the back so i didnt have to get all my rims off set.... hmmmm was thinkin along the lines of 35"x12"x16R baja claw radials after i get the donk rebuilt and a turbo fitted (plus the 2inch body lift shood be fawkin awesome after all that

[dumbdunce]

can't get spacers engineered, can get offset rims engineered.

plus for offroad add the spacers to the offset rims for massive width :)

[brad75]

got any pics of the 75 i got a 75 with lifted springs 3 inch body lift and run 35 bfg muds at the mo.75 mad

[dumbdunce]

what's your email brad, I'll send you a couple of pics of a springover 75 I finished a couple of weeks ago.

cheers

Brian

[fatassgq]

Hey dumbdunce are you able to post the pics up here???
I would be really interested also. If not my email address verve01@dodo.com.au
Hey brad there are some pics of my truck on superiorengineering.com.au website. There does not seem to be a lot of custom 75s on the net I have a hard time finding any
Good to see another 75 freek!

[dumbdunce]

I will email you both some pics tonight.

cheers

Brian

[bj on roids]

I will email you both some pics tonight.

cheers

Brian

email me some 75 series SOA pics too!

So superior shackles did your Shackle Reversal? that same guy just told me it is impossible to engineer a shackle reversal on a landcruiser?

That is very strange indeed!

[fatassgq]

BJ,
Not really that strange. My truck is not "engineered"and I was under the impression that I would never get it engineered. I know that the work done on the truck is A1 (welds etc) and my truck is a lot safer than some 'engineered' trucks I have seen that is for sure. It is registered but if transport got me I would have to rely on them not picking it up (unlikely imo) I knew the situation but It didn't stop me from wanting the mods. If you claim that a sr is able to be engineered great bring it on cause i would probably feel better about driving on the road with it. In my experience just because you have an engineer cert. or a blue plate for that matter doesn't stop transport having a go at ya!
At this stage there is always going to be conflicting arguments about what is legal because as with anything there is always loop holes. I mean if you go by the transport dept in qld book 90% of 4x4s driving around qld are illegal. NO IF"S NO BUTS!

[brad75]

gday brian,my email address is www.taylbrad@bigpond.com.au. i am mad about 75s.maybe i could return some pics as well.go hard [/i]

[dumbdunce]

any more info available on the engineerability or not of the shackle reversal? I did not do a SR on the springover because I was having trouble getting enough up angle on the diff (stupid square axle housing), but I did think about it and may still tackle it at a later stage.

[fatassgq]

Hey Brian (DD)
thanks for those pics, looks like a nice job. Yep the shackle reversal looks like it would definitely need some series knuckle rotating. The angle on that front drive shaft already looks pretty steep?
It would be interesting if you could not get a sr engineered down there and you could a spring over... I guess there is no making sense of dot rules!
As far as I can tell it is only the nose diving under brakes that is a negative. Everything else seems to have imroved with my truck. It is a sua however. Has the owner of that 75 had it offroad yet? What does he think?

Good luck
Brian

[dumbdunce]

I have rotated the knuckles on that front axle about 7 degrees, there is 5 degrees up angle on the diff housing to get the pinion flange higher, but due to the square axle housing I felt it was dangerous to go more angle than that as the u bolts become less perpendicular to the spring perch. could possibly go 10 degrees without a problem. the front driveshaft angles are bad but the unis do not bind across the full range of travel/articulation. with the use of the 55mm spacer constructed from 2 diff flanges I was able to avoid excessive clearancing mods to the crossmember and use the stock front driveshaft.

the other 2 degrees of knuckle rotation is to compensate for the extended shackles but the caster is a bit out, probably over rotated the knuckels a bit but it drives very well (except for some steering wobble from the swampers on 2" wheel spacers!), has been past 110km/h even with the swampers on with no problems.

one of you guy's email address bounced, whose was it (who didn't get the pics?)\

cheers

Brian

[fatassgq]

Hey Brian,
I got ya email. Thanks
In your experience what sort of castor (in degrees) should a 75 be running? Is it different with a spring over axle?
I would have thought with a shackle at the front of the axle that the longer it is the less positive castor you would get. Therefore have to run shims under the perches. Is that what you mean by the castor being out on that truck that it does not have enough positive?
I am yet to get mine checked but it drives very well. I would be interested in any figures for castor so I could compare with what the alignment place says.

[dumbdunce]

caster spec for 75 series ute is .5 degrees +/- 1 degree and it is tolerant of another +/- degree or so without noticable steering abnormality. I have corrected the caster with the springover 5 degrees to compensate for the pinion flange rotation plus 2 degrees to compensate for the extended shackles, but when it was all together it measured up at about +2deg20'(2.3 deg) which means I must have overcompensated for the extended shackles, or the springs are bent - but like you've mentioned it can be corrected with wedges if necessary - so far it drives ok so no need. the upside is a wedge to correct the caster would improve the fromt driveline angles but the down side is that it would make the angle between the ubolts and the spring perches worse.

instead of pulling the front axle and doing all the maths, chopping and welding without TESTING (lucky my maths is pretty good eh :) - next time round I'd pull the axle, tear it down, weld up the perches, cut the knuckles, refit the axle and load it up, rotate knuckles to spec (possibly a LITTLE more positive caster), tack, then pull the axle and finish the welds.

the cruiser front end is remarkably tolerant to bad angles, unlike the patrol! I have 4" suspension lift in my bundera so the caster is out by probably 4 - 5 degrees but it drives fine except for wearing the shoulders of the front tyres. patrols with bad caster wobble like a bitch and/or wander all over the road.

cheers

Brian
cheers

Brian