Full Time 4WD

[Shane+Small]

Hello All,
I have a 1992 Full time 4WD VX Landcruiser. Recentley we were stuck with a failed uj on the front prop shaft. To get home we removed the front prop shaft, slected center dif lock and drove home with no apparent problem. Is this wise? Futhermore as the cruiser is used mostly for towing horse boxes etc and not off road could we leave off the prop shaft, fit free wheeling hubs and operate indefinately like this?

Many Thanks, Shane

 

[Brett]

Why would you want to do that? A UJ is loads cheaper than a set of free wheel hubs?

There is also a modification required to transfer box if you want to go part time, leaving the centre difflock engaged is not a long term solution imho

 

[Fett]

you have the switch then

 

[Rob]

Leaving the centre diff locked disables the ABS and MOT guys tend to not like this. I did however convince them that it works by turning off the centre diff lock but obviously the truck would not move.

 

[Brett]

Would a 92 have ABS Rob?

I think the previous poster should consider that the landcruiser was designed as a full time 4x4, not just for handling or performance but also to spread the torque over both axles.

If you run with just the rear axle connected & diff lock engaged, all of the available torque is directed through the rear, which if you are towing a heavy horsebox (possibly up to the 3500kg limit) you are at much greater risk of snapping a rear shaft or blowing the diff.

If he really wants to go part time, It should really be done properly.

http://www.marks4wd.com/products/part-time-4wd/lc-80SERIESPT4WD.html

 

[Andrew Prince]

I think the previous poster should consider that the landcruiser was designed as a full time 4x4, not just for handling or performance but also to spread the torque over both axles.

If you run with just the rear axle connected & diff lock engaged, all of the available torque is directed through the rear, which if you are towing a heavy horsebox (possibly up to the 3500kg limit) you are at much greater risk of snapping a rear shaft or blowing the diff.

Hmm, not so sure about this - the 80 series pov pack DX (Aus) and GX (SA) models had part-time t/cases and locking front hubs IIRC. My guess is that the locked centre diff is most vulnerable, rather than rear shafts and diff. The part-time 4wd 80s didn't have a reputation for breaking the rear drivetrain to my knowledge (and I doubt these were much different to the full-time 4wd rear diffs and half-shafts).

If he really wants to go part time, It should really be done properly.

http://www.marks4wd.com/products/part-time-4wd/lc-80SERIESPT4WD.html

Agree - Ian Rubie had a centre diff failure not long after playing at Lincomb in 2wd, having removed the front prop and drive flanges. Whether the CD failure was linked to this, I don't know...

IMHO running in 2wd with CD locked and front propped removed is probably ok for fairly short distances and no major loads. I.e. in recovery mode or local running around while waiting for fix a broken CV or drive flange, for example. Long-term use and hauling heavy loads would be best back in full-time 4wd mode, unless properly converted to part-time as per Brett's post.

Cheers,

 

[Jon Wildsmith]

Apart from the truck driving very differently I don't see any problems running with the front prop removed and the centre diff locked. All the part time kit does is change where the disconnect happens i.e. at the centre diff instead of at the front output flange. The part time kit just gains not turning the front output shaft but if I understand it properly you completely loose the centre diff function so you no longer have an unlocked 4wd mode.

 

[Ian Rubie]

Agree - Ian Rubie had a centre diff failure not long after playing at Lincomb in 2wd, having removed the front prop and drive flanges. Whether the CD failure was linked to this, I don't know...

You can not really take my car and things I do to it as an example I gave it absolute hell when in 2WD mode, even made it up the rock steps

Ian

 

[frank rabbets]

All torque going to rear axle may well be a problem in Low Ratio. Isn't that the reason why there is no option but centre difflock when in Low?

My 1949 Land Rover instructions said on no account use rear axle only in Low as if the wheels got stuck the diff would split. Or is this completely irrelevant? [I can take it].

Frank

 

[Jon Wildsmith]

In low you should be able to lock your axle diffs as well as the centre diff With all the diffs locked a single wheel and drive shaft can be coping with 100% of the power and although not indestructible this is how it was designed by Toyota

 

[Andrew Prince]

You can not really take my car and things I do to it as an example I gave it absolute hell when in 2WD mode, even made it up the rock steps

I was trying not to make any judgements, Ian I did think that it was a fair example of what hard use in 2WD might do to the centre diff

 

[frank rabbets]

Yes John I hadn't thought of that, but thinking again all the torque is still going through the crownwheel and pinion with one wheel driving. On the old LR you would still have all torque through same even without lockers. I think a lot depends on driving style, very easy with the clutch perhaps.

frank

 

[Roger Fairclough]

To convert a 4 wheel drive 80 series to 2 wheel drive is likely to end in tears. As the owner of said vehicle has stated he tows horse boxes, there will come a day when that horse box is parked on wet grass and he needs to tow it up hill.

Roger

 

[Dave2000]

It's no big deal leaving the one prop and CD locked. Think of a situation where all diffs are locked, three wheels on wet grass/ice/ball bearings ect and the fourth wheel on good grippy concrete. One axle being loaded as the car attempts to move, the car could be fully loaded and a trailer it will still move and that one axle is absorbing the load, of course I doubt anyone would be stupid enough to floor the throttle but you will be surprised how strong 80 running gear is when maintained correctly.

As Jon said with the part time 4wd kit, all you are doing is moving the 'disconnect' elsewhere in the drivetrain and the aussies have been doing this for years.

regards

Dave