Driveline Issues?

[Paul (SA)]

Hi all,


I am not a mechanical minded person so apologies for the silly question. I have a 2014 NW since new and have serviced regularly etc. I don't do any serious off roading, just using it to tour the country with the family towing our small Jayco Swift.


I am running BFG KO2s.



I notice when driving it weekdays around the city there is a slight "harshness" from the driveline that affects the driving. It feels like there is resistance in the drivetrain that affects the ability for the car to roll nice and smoothly along the road. You can feel it in the steering wheel and pedals. There is no vibration or shudder, just like a resistance holding the car back from traveling nice and freely.



It would sort of like be similar to the feeling you would have on a bicycle when the brake pads are rubbing on the wheel and causing it not to roll nicely.



I have put this down to the fact I am running all terrains on bitumen and I am driving a 4WD diesel but have always wondered if there could be something else to it?


I will quiz my mechanic at its next service, but in the meantime, is this normal for a 4WD being driven around on city roads?


Be keen to hear feedback from anyone else who is more minded about these things than me.



Paul

[tonee]

Was it like this before you fitted the BFG ATs?

This resistance, from my imagination is it slowing down quicker than it used to when you let go of the accelerator and coast?

Sent from my LG-H930 using Tapatalk

[Kingmarz]

Try putting it in 4LL and turn on rear diff lock and driving 100m then turn off R/D lock and put it back into 2D

[drgtr]

What you describe sounds like binding of the centre diff lock.
Like you are in 4wd high centre lock.

As mentioned. Go through the different 4wd modes. Make sure its changing and lights stop flashing.
end up back on 4h

[Paul (SA)]

Thanks for the replies all. I will get my mechanic to take a look shortly.



It sort of does feel more like it is in 4LL rather than rolling nicely along in 4H.



But I went through the gears in 4WD and it all appeared normal.



Have to say I am not a fan of the BFG KO2 - I made a mistake buying them when I do mostly blacktop.

[spot01]

Thanks for the replies all. I will get my mechanic to take a look shortly.



It sort of does feel more like it is in 4LL rather than rolling nicely along in 4H.



But I went through the gears in 4WD and it all appeared normal.



Have to say I am not a fan of the BFG KO2 - I made a mistake buying them when I do mostly blacktop.

I suspect it is simply the normal effect of the tyres - did you notice a difference when they were fitted?



My LT tyres (but not as aggressive as the BFGs) make the car feel like the brakes are slightly on when I lift off to slow down - it often slows down enough to use far less braking than when it is on the factory tyres. It gives the type of feeling you describe. The LTs also use about 1L/100km more fuel. I can easily push my car on flat concrete when it is on factory tyres but it is much harder to push when on LTs. This is all due to the much heavier construction of the casings creating significantly more rolling resistance.



What pressure are you running?
To test my theory, pump them up to the max. shown on the sidewall (mine show 65psi) and see if the car rolls much better - if so, probably just the tyres causing it. But don't drive too far like this - just for the test.

[Mike DiD]

If the Centre Diff is locked there will be no difference in drag when driving in a straight line, but as soon as you turn the wheel from straight ahead, it will be like the Handbrake is on.

[Paul (SA)]

I suspect it is simply the normal effect of the tyres - did you notice a difference when they were fitted?



My LT tyres (but not as aggressive as the BFGs) make the car feel like the brakes are slightly on when I lift off to slow down - it often slows down enough to use far less braking than when it is on the factory tyres. It gives the type of feeling you describe. The LTs also use about 1L/100km more fuel. I can easily push my car on flat concrete when it is on factory tyres but it is much harder to push when on LTs. This is all due to the much heavier construction of the casings creating significantly more rolling resistance.



What pressure are you running?
To test my theory, pump them up to the max. shown on the sidewall (mine show 65psi) and see if the car rolls much better - if so, probably just the tyres causing it. But don't drive too far like this - just for the test.

I think you are on the money. I think it is the tyres and their more aggressive tread on the black stuff.