Much higher revs needed when manual hubs engaged.

jaycey001 · Gate Opener Joined: 17 May 2012 Odometer: 29

Hi

Right, to everyone that is used to driving a manual car this may sound a silly question. but all my previouse 4x4s have been auto, so this issue has never arisen before.

When i engage the manual hubs on my Daihatsu Sportrak there is alot more resistance when driving, and at low speeds you have to give it alot more revs and be very gentle with the clutch to prevent it from stalling. (more so with the selector in 2WD but also in 4wd)

I understand that by engaging the hubs i am now runing in 4x4 so there is naturaly more resistance, i only ask as when my suzuki GV in in 4wd there doesnt seem to be any increase in revs to get it going (it auto)

Any comments apreciated
Cheers
j

TheClunk · Posted: Thu Jan 17, 2013 1:45 pm Post subject:

Of course it will.
When you select 4wd, the engine is having to turn twice the amount of ironmongery to propel the vehicle.
Before it was powering one transfer box, one diff and three prop shafts. Now it's powering one transfer box, 2 diffs and 6 prop shafts.
Also as you have the 2wd/4wd option, then you probably don't have a centre diff. So with all the tyres at different diameters (they will be) the engine has to force one wheel at least to break traction to avoid wind up.

RichardD · Posted: Thu Jan 17, 2013 4:08 pm Post subject:

wot he said but with addition that if it is seldom used in 4wd and the front axle has not been service often enough the oil may be much thicker/dirtier?

Tractor Stig · Posted: Thu Jan 17, 2013 6:37 pm Post subject:

since when does a 4x4 have 6 prop shafts??? you say you engaged the front hubs....ok, are you in 4h or 4l when moving off?? if your still in 2h then all your turning at the front is 2 wheels, 2 driveshafts, a diff and a prop shaft, so if its hard work I would imagine you have a front diff issue, in 2h it wont really require much more rev to turn, so you gotta look for some kinda tight spot issues between the shafts to the diff.

agrimax · Posted: Thu Jan 17, 2013 6:43 pm Post subject:

Think he means that there are 2 half shafts in each axle plus the 2 prop shafts to each axle giving 6 in total.Curious as to why the tyres ''will be'' different diameters though?

ivorbiggin · Posted: Thu Jan 17, 2013 10:26 pm Post subject:

It would be so much easier if people would give us a clue as to the make, model and year of the vehicle.

Your Boeing 747 dosnt have any drive shafts, you dont state if you have Pratt and Whitney or RR engines.
If its fitted with P&W engines, i believe there is a problem with 1 of the 4 going into reverse thrust while in 4x4 taxi mode, giving you a severe one sided drag effect.
The cure is to throttle down on the effected engine and give it some serious elevator on the opposite wing to the effected engine. Rudder control wont make a lot of difference while in taxi mode but might have a detrimental effect when in the air.
If you havnt cured the problem by the time youve reached the end of the runway, PRAY

Xpajun · Posted: Thu Jan 17, 2013 10:34 pm Post subject:

ivorbiggin · Posted: Thu Jan 17, 2013 10:39 pm Post subject:

Daihatsu with wings or without? Laughing

Made from 1988 to 1998, 2 engine variations depending on year, both 1600 cc,
Year of manufacture narrows thing down.

Please put year make and model in caps as im a blind old git, and cant see if you dont shout at me loud enough