Having 4WD on road?

[Haggs]

Ok so I was driving home yesterday and pulled into my driveway and much to my dismay I noticed I had accidentally left it in 4hi from the snow storm the day before. So basically I drove about 150km in 4hi with hubs locked on drive asphalt !!

Is there anything I can do about it now or can how do I tell if I have done any damage to worry about?

Drew

 

[David*BJ70]

Ok so I was driving home yesterday and pulled into my driveway and much to my dismay I noticed I had accidentally left it in 4hi from the snow storm the day before. So basically I drove about 150km in 4hi with hubs locked on drive asphalt !!

Is there anything I can do about it now or can how do I tell if I have done any damage to worry about?

Drew

There is no problem at all.

I'm just curious about how you can't realize your truck is in 4hi and don't notice it when you turn on dry pavement ?

 

[crushers]

with the staight roads here in Alberta you might have gotten lucky...
engage the front hubs, drive straight and try engaging the front end while moving, if no sound then good chance you are fine. if you hear a noise disengage imediately and check the front hubs are actually locking properly.

i have had a half dozen trucks in my shop in the last few days with "front end won't engage" problems, every one was a rusted or dirty hub not engaging...

driving in 4H on hard packed surface can be an expensive ooops...

 

[Haggs]

In regards to not knowing it was engaged, like Wayne said our roads in Alberta are very straight the only turns(of any significance) I made would have been in residential areas where the roads are icy and snow covered.

Thanks for the info Wayne I will try it today after work.

 

[Gold Boy]

is there a max speed for when you engage 4H button on the fly?

thanks

 

[crushers]

as long as the front hubs are locked and you are driving straight then you can engage the front end at any speed. i have done this for a test at 160 km/hr with no noise at all, smooth engagement.

i was showing a customer how to engage the front of his HZJ77 properly.
"lock the electric hubs when standing still"
"engage the front drive when steering directly ahead when the hubs are locked"
"do not drive in 4H when on firm packed dry ground"

he emails me back later that night SCOLDING me for "treating him like a child"...
i guess you can't make some people happy.
<but if i didn't walk him through it guess who he would try and sue to fix his front end should it have broken due to lack of instruction???>

sheesh

 

[Gold Boy]

Wayne, "sheesh".... but good on you for your tuition.

sometimes i here a quiet clunk when i engage 4H on the fly, is this a normal?

cheers

 

[crushers]

there really should be no clunch since everything is turnign at the same speed anyway...
if it gets louder then check it out...

the most noticable sound when not engaging properly is a granding noise, this occures because the front end is not turning and the gears are trying to mesh... this is bad...

 

[roscoFJ73]

as long as the front hubs are locked and you are driving straight then you can engage the front end at any speed. i have done this for a test at 160 km/hr with no noise at all, smooth engagement.

i was showing a customer how to engage the front of his HZJ77 properly.
"lock the electric hubs when standing still"
"engage the front drive when steering directly ahead when the hubs are locked"
"do not drive in 4H when on firm packed dry ground"

he emails me back later that night SCOLDING me for "treating him like a child"...
i guess you can't make some people happy.
<but if i didn't walk him through it guess who he would try and sue to fix his front end should it have broken due to lack of instruction???>

sheesh

Why did he have to email you back to tell you that,couldnt he have said something face to face? It kind of makes him look like a childLOL

The old brochures say 4wd can be engaged at up to about 75 kph

 

[Haggs]

I engaged 4hi again and there was no sound at all. Thank goodness. Thanks for the info Wayne.

 

[crushers]

Why did he have to email you back to tell you that,couldnt he have said something face to face? It kind of makes him look like a childLOL

you have no idea...

 

[lowenbrau]

I'm pretty sure the brochures were being cautious. If you really need four wheel drive should you be going faster than 50mph? Its been a long time since I had a front driveshaft that would go that fast without turning the truck into a giant dildo anyway.

Somebody mechanical explain what you'll damage in the t-case if you drive in high range one dry pavement. I'll argue that a split Cruiser case will stand up to it just fine. Those rules apply to cases with centered rear outputs.

 

[crushers]

I engaged 4hi again and there was no sound at all. Thank goodness. Thanks for the info Wayne.

glad i could help

 

[crushers]

Somebody mechanical explain what you'll damage in the t-case if you drive in high range one dry pavement. .

i am far from mechanical but here is my take on the matter. going straight there is no problem but when turning a corner all 4 wheels are turning at different speeds, when this happens there is gear bind occuring. the t/case is where the blunt of the force occures and this can bust them or strip teeth or even a weak birfeild could blow...
if you have any weakness in the drivetrain this action will find it...

 

[Jim_Hbar]

Somebody mechanical explain what you'll damage in the t-case if you drive in high range one dry pavement. I'll argue that a split Cruiser case will stand up to it just fine. Those rules apply to cases with centered rear outputs.

The whole drive-train is stressed, and the weakest link (be it the transfercase, u-joint, birfield, hub or tire contact) will eventually fail. When a vehicle turns (ignoring tire slip angle), the instantaneous centre of the turn is on a line through the rear axle. Therefore, the front end travels on a larger radius than the rear, and thus has to travel further - (go play with a grocery buggy to confirm the concept) There can be incredible torques generated in a locked drive-line. Same thing can happen if the tires are worn to a different diameter on either axle, or a slightly different gear ratio is used in the diffs (old Fords had 4.10's in one end, and 4.11's in the other, or something like that) - doesn't have to be a corner. Anything that will allow a tire to slip slightly will release the binding.

An old friend once came out of sandy parking area onto pavement, and drove off locked in 4HI - made it about 50 yards, and the truck slowed down and ground to a halt - he slipped in the clutch, and the truck actually traveled backwards from the torqued-up drive-lines... In that case, it was due to tire diameter

 

[roscoFJ73]

There is a mechanic who works in a mine repairing 75 series that used to post on the Landcruiser discussion board.
He said he has winessed hubs explode from being driven on a solid surface caused by the immense binding.
The mine landcruiser are permanently locked in low range

If you mark the tyres at 12 oclock with a piece of chalk and go for a short drive it becomes apparent how much difference the F and R wheels travel.

 

[champjack]

i would jsut like to say i realy had no idea . heard some things but was never sure . So was staying away from one of the things that makes this ride so great .

Thanks guys for this post.

 

[Entaran]

Out of interest, in a 75 series (specifically a HZJ75) with manual locking front hubs and manual engagement 4x4....

If I don't lock the hubs in, but am say towing a load of wood out of the forest in 2wd, can I slam her in 4 lo (effectively 2 lo) and let the front driveshaft freewheel (as it's not locked in) or will I cause damage? (This is purely for the reduction in gearing)

I am usually not lazy, and my hubs are locked, but sometimes they aren't and you just don't want to get out on a long climb with 3.5 tonnes of wood behind you and another tonne in the back... I don't trust the park brake that much. So will I actually cause damage or is it pretty much fine?

 

[crushers]

If I don't lock the hubs in, but am say towing a load of wood out of the forest in 2wd, can I slam her in 4 lo (effectively 2 lo) and let the front driveshaft freewheel (as it's not locked in) or will I cause damage? (This is purely for the reduction in gearing)

if you "slam her into 4Low" with out coming to a stop you can and will do damage. you are still trying to engage a dead driveshaft. if you come to a stop and engage 4L and then drive with the front unlocked you will not cause any damage...
BTDT many times...