Thread: 6x6 Perentie performance off road?

I've been considering remaking the rocker beam in a different form, rather than a straight horizontal beam, instead an inverted "V" shape. This would give the dual benefit of slightly raising the rear end and allowing more angular rotation of the beam before hitting the chassis (or possibly not even hitting the chassis at all!).


Removing the straps/cables should be OK provided you check the extended lengths of the shocks at full articulation.

Thanks guys, I think I'll give it a go before the excursion next weekend. I do know they are very strong springs!! I had 4.5 ton on the back and it took the load beautifully. Which is great if ur trying to carry a small planet around all the time. Not so good for the mrs when going over a bump or speed hump.

One think I've considered gunner, is putting the leaves over the axle housing rather than under. The spring carriers have very little clearance and foul when in soft sand.

If your playing around with suspension, maybe you could look at doing that?...then tell us how you did it


Just catching the perentie bug.

• 1990 Perentie 6x6 Air Defence GS
•2013 Range Rover Sport

Originally Posted by TK_Co

One think I've considered gunner, is putting the leaves over the axle housing rather than under. The spring carriers have very little clearance and foul when in soft sand.

That would give you a lot of lift, but I think it might put too much angle on the rearmost driveshaft UJs. That shaft is very short; you can see the flange where the shaft starts at the very bottom left of this terrible photo.



I think 303's idea has legs and will probably make the most of the Perentie design, which is unfortunately quite constrained.

One of the things to keep in mind is that the articulation available is related to the load the vehicle is carrying. Very lightly loaded, the rocking beam sits like this:



So the middle axle doesn't have far to droop. Carrying load you'd have more articulation. It would be interesting to see how much difference in articulation loading the back of the vehicle up until that beam was level would make. 303: maybe part of your video?

A better option for those doing mods would be to swap to a setup which allows the axle group to tilt as a single unit. E.g. buggy spring setup usind a single inverted spring pack per side, which can pivot in the centre and is rigidly fixed to each axle.

Stick a camelback and 6 point on it?

Originally Posted by Blknight.aus

Stick a camelback and 6 point on it?

There's lots of ideas. Maybe someone should start a 6x6 suspension thread? I see there are some companies (6x6 Australia, MDT, off-road trucks Australia) that specialise in 6x6 and 6x6 suspension. Has anyone changed the suspension on there 6x6 yet?


Just catching the perentie bug.

• 1990 Perentie 6x6 Air Defence GS
•2013 Range Rover Sport

Originally Posted by Dervish

One of the things to keep in mind is that the articulation available is related to the load the vehicle is carrying. Very lightly loaded, the rocking beam sits like this:



So the middle axle doesn't have far to droop.

I've just a look at the rocking beam on my 6x6 and it doesn't look like the photo above. I may be an optical illusion from the angle the photo was taken but the beam seems to be pointing down at the front end . On my 6x6 the beam is sitting absolutely level, on level ground with a light load. The gap before the beam contacts the chassis is about 30mm each side but this gap (that ultimately restricts articulation) is right at the pivot point and the axle(s) centre is 450mm away from the pivot. I'm not able to do the maths right now but this should give a reasonable amount of articulation. The axle straps are the limiting factor on mine, and not the rocker arm contacting the chassis. There are no marks on my chassis to indicate any contact here.

I am considering lengthening the straps but I wouldn't remove them entirely due to the risk of catastrophic damage to the rear tailshaft if it were to separate at the spline. A few measurement up on jacks would be a good starting point.

The main issue I have had off road is the rear end 'pig rooting' in loose going up-hill. This thing is really no good on round river rocks or unpacked loose ground or ploughed paddocks. Skipping on the middle axle seems to set the rear axle off with causes the middle axle to bounce and on it goes......Sort of like a see-saw on steroids. Foot of the throttle seems to be the only fix.
Pete

Your vehicle.probably doesn't have the rear axle.ha gong from its check strap because the wheel.is removed.

On level ground unloaded you can drive the vehicle with one axles wheels removed without drgagging the other axle, that's part of what the check straps are for

For your off-road problem first check your cdl is engaging and that you are not cross axling the rear pair when you drive.

Raise your idle speed using the ha d throttle so the engine sits. At about 1000rpm let it walk and if you need to lower the tyre pressure.

Setting the vehicle up on the right line with the right engine power and gear with the right loans and tyre inflation is key to getting the best out of your 6*6