Gravel road and part time 4wd

[Basie]

Hi

My 79 have part time 4wd and when in 4wd there is in effect a locked central differential

Does driving on gravel roads ( we have many leading to interesting places ) with H4 engaged make a difference in road holding/handling. Some swear that you use it as such for safety reasons. Personally driving at 90-100km/hr, I felt that the vehicle was more prone to wandering on the road, but that is not a scientific finding.

I would like to get some input from whether it is good or not

Thx

 

[Locked79]

4wd vs 2wd is a personal preference. I personally don't use 4wd on gravel roads and used to travel around 400km a week on gravel roads in my 79. If the traction is too high, 4wd can lead to axle windup but if it's loose gravel there should be no issue. I just like the way 2wd handles. Its what I'm used to.

 

[elkaholic]

I will run 4wd on gravel when the road surface is what we call washboard in the US South - have heard it referred to as corrugated as well. It seems to help keep the rear from stepping out on turns .... My $0.02

 

[Josie'sLandCruiser]

Hi all,

It will not hurt your part-time 4wd system to drive in 4 High on loose gravel roads. 4 High probably gives better control than 2 High on such a road surface at high speeds, though whether one really notices is a personal call. Your fuel consumption will be (slightly) affected.

Regards,

Alan

 

[Basie]

Thanks for the replies. It looks as it does not have major advantages in terms of road holding and handling and actually very few disadvantages as well. One advantage mentioned to me from a quite knowledgeable mechanic is that the front differential gears wear out by being vibrated on one area if the front hubs are at least not engaged, but that it only where really long distances traveling on 2H with disengaged hubs on bad roads.

We call it ( directly translated from our vernacular ) corrugated iron roads, but wash board is quite descriptive and except for the bone jarring the rear has stepped out of line on a straight road a few times. I cannot see how using 4H will help with that and it is usually because to high a speed and too high tire pressures for the road

Good (and bad) roads to all

 

[JuanJ]

Hello,

As others mentioned already, driving in H4/4WD in a gravel road would pose no problem.

Regarding the locked central differential, keep in mid that 70 Series, particularly late model ones (71/76/78/79,) have a 4WD Control Unit, whose computer is located on one side of the glove box. It regulates engine power output, among other things, and it might feel like a locking differential. Your 70 Series is a bit more sophisticated than it looks.

As for driving, many people are used to 2WD for the roads in question. Others prefer 4WD because of the additional traction. From personal experience, try to feel the road. If you feel the Cruiser slipping, shift to H4 and continue driving; if you do not, keep going.

Hope this helps.





Juan

 

[Basie]

Thanks JuanJ

Mine is a 2003 model and all manual shifting and it does have a EFI engine, but the transfer case is sometimes of the two handed type. accodring to its book when in 4H the central differential is locked.

My personal feeling is that I am more comfortable in 2wd on gravel road. Steering is just easier and less wandering on these long of tracks forming into the loose gravel

Thanks again for all the replies