[barrymallen2]

I own a D40 dual cab with a cuddy canopy. This is the first 4WD ute I have owned.
On a undulating cement road the vehicle starts to bounce in the rear and it is due to chassis flex between the cabin and the rear tray.
If you get the frequency of the road bumps and the speed correct the bounce was so severe that I stopped the vehicle because I thought I had a flat.
I asked my local Nissan service about the problem and he said that all utes do it but that the D22 is not as bad as the D40.
Does anyone have any experience with the chassis flex and resonance with dual cab utes? Is this normal with all utes?

 

[Martin from Downunder]

Never head that before , what springs are you running , tyre pressures etc etc do you carry loads , all question you need to ask yourself

It is possible that the spring rate is so out of wack with an unloaded ute that rough roads could make it unstable , this would apply to any ute not just dual caps. though some bags of cement or what ever in the back and see it that stables your vehicle

Cheers Marty

 

[Buzurk]

Id say rear springs and shocks . Standard nissan ones are a joke

 

[Sproga]

I say slow down and drive to the conditions.:crikey:

 

[barrymallen2]

Standard rear springs and shocks.
The dealer knew all about the issue. He told me his mates canopy hits the rear of the cabin on the same section of road.
I have the canopy and carry about 100kg of tools so about 200kg of weight.
I recently had the rear springs reset and an extra leaf added by EFS but it made no difference to the chasis flex.
If you do a quick bounce on the rear bumper step you can see and feel the flex between the cabin and the canopy. This is nothing to do with springs or shocks. When you are driving on the cement roads In the rear vision you can line up the heater bars on the rear window with the tail gate and you can see the bounce. I suspect that the high weight of the canopy may make the situation worse.

 

[barrymallen2]

I say slow down and drive to the conditions.:crikey:

Driving at 90k/h in a 110k/h section of the Pacific Highway is a problem to you?
The flex has almost gone at 110k/h.

 

[Buzurk]

Mate i havent noticed . Ill have to try to check mine. Poor nissan quality again

 

[Pete22]

Now done 40000km in my ute and on some of the worst roads in Aus (eg Gary and Gunbarrel Highways) and haven't noticed this. Then again I have replaced my rear springs with a 7 leaf Snake Racing/RidePro setup.

 

[kyleb]

Hi Guys,
I just noticed a dent in my cab where the top of the tub/bottom of canopy has hit the cab, due to the chassis flex. I dont give my vehicle a hard time, but it does have a bit of weight in the back (only drawers, battery, fridge slide etc). On the right hand side I have a small minibike fuel filter connected to my diff breather line. This is right up near the top of the tub, just below the canopy. This too has dented the cab, but there is no damage to the filter, so the cab panel must be like cardboard!.

Anyway, I'm guessing I went over something that caused the back to bounce a bit. I have only had this happen since I fitted the drawers (and their only 75kgs incl fridge slide) so I reckon the chassis is flexing. I am upgrading the springs again (going from a performance ride to a constant load spring) as the suspension guys told me it's starting to run on the second stage all of the time. This may have attributed to the issue as the back has become a little more bouncy lately. But that aside, the chassis must have a fir bit of flex in it.

Does anyone know if you can loosen the tub bolts and slide it back a little to gain a greater gap between it and the cab?

 

[Aussie Frontier]

The tray should only be maybe 6 bolts and so shouldnt be too hard to slide it back within reason .