Bunny hop, sideways. on my MN

[Cage]

Had a couple of scary moments in the last two weeks.

The first was at about 80km/hr on a dirt road, nothing in the back, when I hit some corrugations and the back hopped sideways off the road, fortunately only about a 20cm drop, and having grown up driving on dirt roads I got it back onto the road and backed off.

The second incident happened at about 30km/hr, downhill, trailing throttle, hit some corrugations, and the back end started hopping toward a rather nasty drop. Scared the crap out of me having no control.

Now I appreciate the fact I'm probably not the first Triton owner to experience this, and that having nothing in the back was probably a contributing factor, but surely these vehicles should be designed to operate safely under all operating conditions.

OK, I guess I need to upgrade the shocks. Do I need to do both the front and the rear, and what is the best way to go for both unladen and laden stability.

PS: I should have added that I'm running 265/75 Maxxis AT 980 Bravos on 8 x 16" rims, front 35psi. rear 34psi

[Lunny]

Front and rear shocks... Or just replace it all

[Cage]

Or just replace it all

What with, a Ranger?

[Lunny]

That or a new kit...

[krazed]

I'd recommend for one decent tyres to suit the terrain ! if you are doing alot of dirt driving i'd be going mt's for sure . I did a trip with the inlaws through a state forest and it was raining (road was clay base so slippery) . I was doing 60-80k with the muds no dramas it was like driving on a highway . they had maxxis at's and i lost sight of them within a minute . within a couple of mins we ended up turning around cause they only had ats and were sliding all over the place ! . I'd also recommend a sussy upgrade as the stock is not worth a pinch of sh1t . Other than that i cant see you having a problem

[mIwoo]

sounds more like a typical light end ute problem to me.

[MilkmanDan]

sounds more like a typical light end ute problem to me.

x2

Leaf sprung rear end axle hop on dodgy surface. Not uncommon and yes like you said can catch you unexpected.

I don't know a great deal about the triton rear end yet, I'd hazard a guess at maybe a better shock in rear if you are going to be using those roads fairly often, also maybe worth dropping a couple of psi out the rears to help absorb some of the movement.

[Dunga71]

Used to happen to mine all the time when it was stock since the Ultimate lift,canopy and tub fit out I don't get any sideways chatter.
Lower your pressures if your doing a Fair bit of that wheeling and add some weight to the tub I used to have a couple of 20lt water containers full in the back all the time 50 odd kilos made a huge difference to the ride,anyway have a play with a few different things you will find a happy medium I'm shure

[Colsha]

I've noticed this a lot lately when hitting corrugations or pot holes in dirt roads. I just assumed that was what utes are like. The ASC seemed to straighten me up pretty quickly though.

[c-dale]

Crossing the train line used to do it for me too, scary. ReKon sorted sorted it

[harvster]

I had the same bunny hop and rail crossing sideways shuffle on my GLX, replaced the shocks all round with Ultimate shocks, and made the world of difference

[Lunny]

Crossing the train line used to do it for me too, scary. ReKon sorted sorted it

They are real bad on train line crossings...

[stackator]

Icebox with 3 slabs of beer = rally time

[kxboss]

Are you in 4x4 high?

Only ever happens to me when driving in 4X2 on dirt

[trouble]

If it's the suspension 4x4 will not help.
The tyres will still bounce off the road surface therefore not making contact therefore no traction, causing the sideways affect.
Only when there is contact between tyre and road surface will 4x4 help.

[Cage]

Are you in 4x4 high?

Only ever happens to me when driving in 4X2 on dirt

I was in 4x2 mode but to be honest I can't see what difference being in 4x4 would make.

I've spoken to some suspension 'experts' and some swear it's the springs, and others say it's the shocks, so I'm none the wiser. What I don't want to do is fork out money on a 'fix' that isn't.

I'm just waiting on a call from Brendan at Ultimate. From what I've read on this forum they seem to know their stuff.

[trouble]

FYI I had the same problem years ago when I bought my Triton, replaced the shite stock suspension (springs & shocks) never looked back, however I also carry around 300kgs in the tray.

[Earlyninja]

Sounds like a bit of physics too as corrugations set up a uniform wheel bounce frequency.

When driving with empty tub, lower the rear tyre pressure by about 4 psi lower than front tyres. Softens ride and makes front and rear tyre contact patch more similar. Also check your tyre wear (overinflation/underinflation) and adjust psi to suit.
Give this a go, and see if it makes a difference.
Lots of people run higher pressures in the back because they carry heavy loads, but becomes detrimental when empty.

[Cowboy Dave]

I reckon 4x4 makes a huge difference to stability in the dirt. Sure if the wheels aren't touching the road they can't help but realistically if none of your wheels has traction then you're in a world of hurt anyway. The difference between a front wheel that simply rolls along as it is pushed and a front wheel that can grab and pull the car through something is a significant difference. Same reason I always grab 4H when it rains. Reminds me of my old subarus, they were some seriously stable cars.

[trouble]

I agree CD like I said before which I reckon it's the shock absorbers, as we all know they are shite on our trucks from stock

[Cage]

Thank you all for the helpful replies.

I've just ordered a rear sway bar and a pair of rear twin tube gas shocks from Ultimate. The bar is a MK11 with a modified mount for better clearance.

I still fancy I can feel a little sidewall flex from the 265/75's and I'm hoping that with the reduced body roll it will eliminate that, and if so I can play round with dropping my rear tyre pressures a bit.

I'll probably get the front shocks done as well to keep it all matching, although Brendan said that they would adjust the valving on the rears to match the front shocks, which probably aren't much bloody good anyway.

Cheers

PS: And I'll run in 4WD when on the dirt in future. Sure can't hurt anything.

[trouble]

Re: the 267/75's yeah you will feel the sideways flex but you get use to it soon enough

[oldplodder]

Make sure you have not turned off ESC?
Check tyre pressures, lower for dirt.
Run in 4wd, can select on the fly.

[Grumpy]

Mine is a 2007ML Auto - was thinking of upgrading with Ultimate when the Triton made the decision for me. Slow sweeping curve on bitumen, 100kph limit, I was doing 80, touched some rough surface and Triton danced across the road. Frightened the crap out of me, Ultimate suspension installed, same tyres, all bloody good now.
. . . . . Grumpy

[Snooozy]

I nearly always flick it into 4x4 when I hit a dirt/gravel road.

makes a huge difference to the traction as the front gets to pull the vehicle helping it stay pointing in the right direction.
this is where I wish I had super select

I am sure your shocks are a large part of the problem though.