No 4wd..

[benedmonds]

I am now convinced my swb 1999 colorado is only running in 2wd.
I thought for a while it was just the diff lock that wasn't working, (the light will flash but not turn solid) but now think it's only in two wheel drive. It's very embarrassing when your four wheel drive gets stuck in a flat wet feild..
I've read the actuator threads, so think that is a likely issue but what else should I be looking for?

 

[Beau]

The colorado, along with all Landcruisers are all FULL TIME 4 wheel drive. There is no choice of going into 2wd from 4wd.

The centre diff just locks all the wheels, so they all rotate the same speed (should be used on slippery surfaces)
The rear diff lock is the one you have stuck. This locks the rear diff, so no matter what, both wheels will spin when power is applied. It's a common issue for the actuators to be stuck, some can be freed, but you'll find most of them are badly corroded and a new actuator needs to be installed - Milner...

 

[benedmonds]

I know it is supposed to be all time 4wd but I think it is only running as 2wd.
I guess the first thing to check is the actuator but am concerned there will be more issues.

 

[BobMurphy]

I know it is supposed to be all time 4wd but I think it is only running as 2wd.
I guess the first thing to check is the actuator but am concerned there will be more issues.

The actuator is the Transfer Lever next to the gear lever - there are no electric actuators in the Transfer Box !

The Transfer Lever doesn't select between 4-wheel drive and 2-wheel drive, it only locks the centre differential or selects low ratio.

What makes you think its only running in 2-wheel drive???

If there was a serious problem in the Transfer Box, such that it was only driving one axle, you would usually have to run with the centre diff locked to get any drive at all.

The same would apply if the front or rear axle differentials had broken - you would have to lock the centre diff to get drive to the other axle.

Same again if you had broken a half shaft.

Is this a "UK Spec" vehicle?? Some '90-Series' destined for other markets (i.e. Australia) had part-time four wheel drive and no centre differential (like a Shogun).

Let us know the symptoms and we'll try to help.

Bob.

 

[benedmonds]

It is a UK spec.
I don't think the 4wd is working as it gets stuck very, very easily. Just the back wheels spin.
I tried getting all the wheels spinning on some ice and it only felt like drive was at the rear.
When using the DL switch (next to knee) in low I get a flashing diff light but no change in traction.

 

[geo-smc]

The DL switch will only lock the rear diff,if the light is flashing then it is not engaging.this can be siezed with lack of use or corroded.
the rear difflock wil not make any difference to your four wheel drive,,any 4x4 that has a two wheel drive option usually dosent have a centre diff

 

[silvercruiser]

I take it you are getting the amber/orange light up by your speedo clocks when you push the transfer lever forward to get locked high range or right/forward to get locked low range? what tyres are on the landcruiser? as crispin also used to get stuck on grassy fields with dunflops on. when the centre diff isn't locked it sends more power to the rear wheels (i think its a 60/40 split) so the rear wheels will spin first but if you lock the centre diff it should be 50/50.

 

[Graham]

Just thinking outside the box for a minute.

You do have a front prop shaft in place ?

Gra.

 

[Beau]

On a wet field, you should lock your centre diff, this should enable you to have more grip and limit slip. With the centre diff open, all it takes is one wheel to spin freely and you're stuck.

Once the centre diff is locked, power is sent evenly to both the front and back, but if you have one wheel spinning on both front and back you wont move much. You can then lock your diff, which would spin both the rear wheels no matter what.

I believe you must lock your centre diff first, before putting your rear diff lock on, is this correct guys?

 

[Doodle]

IIRC, you have no choice - the rear locker circuit doesn't become active until you have engaged low range, by which point the centre diff is already locked.

 

[Shayne]

I haven't had the chance to properly test the lockers on my 90 yet but if i were you i would go back to the field . Select LL on your small gear stick , then rock back and forth for a minute or so using first gear and reverse as usual just to be sure my low box was properly engaged as i'm inclined to think mines never been used . That done i would turn the rear diff locker switch (next to my knee) and repeat the rocking process hoping to free up the previously unused parts .

All that done toodle on up to an unmarked stretch of grass , stop and turn your steering to full lock . Now give it some welly and drop the clutch and the truck should do a full 360 doughnut with all 4 wheels spinning and each leaving their own tracks . You can then be sure you are running in 4 wheel drive at least , and if your lucky it will free up your lockers a bit .

My guess is you have rubbish and over inflated tyres designed to improve fuel consumption while driving the kids to school rather than going offroad . No fault of your own i think everyone on this forum changed the tyres as soon as it became possible when they first bought their truck .

 

[benedmonds]

It will go into low range OK, but no dash lights come on.

It's got BFG all terrains, so an aggressive enough tire.

 

[Shayne]

Do the doughnut anyway (you don't need to use the low box) if all 4 wheels don't spin leaving separate skid marks then Graham is probably right the previous owner may have disconnected the front shaft . I believe this was often done (years ago) to landrovers that spent most of their lives on tarmac because early permanent 4x4's had all 4 wheels running at the same speed all the time which meant tyres wore out very quickly .

If you can do the doughnut and establish you do have 4x4 then your question is - does my rear diff work , and the answer is almost certainly no because it is such a common problem and so expensive to fix for very little reward most just leave it broken . You only want to use your rear diff lock when your actually stuck anyway , its a last resort , just one more thing to try before you have to climb out and sink knee deep in mud to fasten a tow rope on .

If you have 4x4 and BFG and your still getting stuck on a flat wet field i can only guess you have either too much air in your tyres or your using to much throttle , as soon as tyres start spinning they may as well have no treads at all . But that said if that particular field is soft mud on top of hard clay it would be like driving on a sheet of ice covered n wet slush and nigh on impossible to get grip .

 

[silvercruiser]

If the front shaft was off it wouldnt move without the centre diff locked, and if the centre diff is locked you would have a light on the dash

 

[BobMurphy]

It will go into low range OK, but no dash lights come on.

It's got BFG all terrains, so an aggressive enough tire.

OK, If I have understood this correctly, you move the Transfer Lever forward but you don't get the amber "Centre Diff Locked" light on the dash.

From this position you can engage Low Ratio and that works normally.

Moving the transfer lever forward doesn't actually lock the centre diff (!) - it tensions a spring that should allow the Centre Diff Lock Selector to move when the gears line-up (that's why it can take some time to engage/dis-engage).

The amber light comes on when the Diff Lock Selector has moved to the locked position (e.g. it isn't dependent on the lever).

It sounds to me as though your Centre Diff Lock Selector isn't moving (the shafts will be doing the right thing as there are detent balls and an Interlock between them to stop them becoming mis-aligned).

Have you changed the oil in the Transfer Box recently?? If so, what was it like (did it have water in it)??

The sleector forks are at the top of the gear cluster and will only get oil that is splashed up from the main gear cluster - the oil pump in the Transfer Box won't help them.

Change the oil, fill it up to the level plug, give the truck a good run to warm everything up and then keep trying to lock the centre diff. It may take a while but eventually it should free-off.

The Centre Diff can be locked on the road up to 50/60MPH without trouble (but don't leave it engaged on a dry road).


Bob.

 

[clivehorridge]

You only want to use your rear diff lock when your actually stuck anyway , its a last resort , just one more thing to try before you have to climb out and sink knee deep in mud to fasten a tow rope on.

Sorry guys, but there's so much good advice going out and almost no feedback coming in. It's not possible to resolve a problem if we're not advised of the circumstances and situation.

Not wanting to hijack the thread, or anything, but I can't agree with you Shayne as I've re-quoted. There are many deep clay mud steep gradients on my favorite track/trail and the only way up them in my 80 is to gun it in 3rd low ratio (LR) (CDL) with at least the rear diff lock on. It will pull me through up to the diff casings in heavy mud, but without the rear locked, I'd be stuck every time.

Creamy topsoil that has a high clay content is terrible stuff in the wet. I've had to winch myself up my garden a few times, and that's not very steep at all. I'm running GG AT2s and I've done damage to the grass much to my wife's annoyance! Winching is less hassle than winding up her indoors!

So I can imagine even a LC getting stuck if the driver is not quite familiar with the vehicle. No offence meant.

 

[clivehorridge]

Oh and BTW none of my lockers show a lock-out red light, but they all work 100% On the flashing yellow. The return signal fails on all of them but they all work.

Too many flashing lights on these cars, it's mechanics and mechanisms we need, not a light show!

 

[Shayne]

Oh and BTW none of my lockers show a lock-out red light, but they all work 100% On the flashing yellow. The return signal fails on all of them but they all work.

Too many flashing lights on these cars, it's mechanics and mechanisms we need, not a light show!

Got to agree with you there Clive pretty lights rarely help in most cases . with regards to the diff would you not say its a whole different ball game when your talking about an 80 and i'm talking about a shorty 90 ? IMO from what i've read on here and other places about 90's breaking diffs , the 80 is built like a tank ready for a war zone , everything on it is gonna take a lot to break . Unfortunately (as i own a 90) i'm inclined to think the 90 is not nearly as tough which is why i feel full diff lock is more of a last resort thing than a 4x4 mode .

 

[clivehorridge]

Got to agree with you there Clive pretty lights rarely help in most cases . with regards to the diff would you not say its a whole different ball game when your talking about an 80 and i'm talking about a shorty 90 ? IMO from what i've read on here and other places about 90's breaking diffs , the 80 is built like a tank ready for a war zone , everything on it is gonna take a lot to break . Unfortunately (as i own a 90) i'm inclined to think the 90 is not nearly as tough which is why i feel full diff lock is more of a last resort thing than a 4x4 mode .

OK Shayne I'll give you all that, cos I've never driven a shorty 90 and I shouldn't have disagreed like I did.

But, I think our friend Ben Edmonds has either fallen asleep or he's a bit tangled up with all the (valid) stuff that's been posted.

I would suggest that he follows this test pattern:

As correctly stated (above) if he only has the rear shaft on, then the centre diff has to be locked to drive, either by selecting it on the dash switch or by using low ratio. I don't care what lights are flashing, if the centre lock works he'll go along, of it doesn't then it won't. Fact.

The lights may be just leading him off the truth if they are not working correctly, so let's ignore them for now, like I do mine!

Next, if he has the rear and the front props on, which I suggest he has, then I advise him to park on a gravel car park or wet asphalt, select centre lock (or low ratio) and the rear diff lock. Drive very slowly in 1st gear on full steering lock, very slowly means tick-over with the clutch slipping a bit...! If the diff lock is working, the axle will wind up and after less than 1 meter, the inner rear wheel will skip and fling stones everywhere. On wet asphalt it will skip and the car will hop. (Or as Shane has suggested the half shaft will snap)

Do you really think the 90 is so weak Shayne?

On wet grass it will just slide and he probably won't feel it. If none of the above happens, then the rear diff lock ain't workin'.

The front diff lock is easy. If you can steer the car with the front locked on asphalt, then it's not working. If it is working, it feels like the power steering has broken. If the steering feels normal, then it's not working.

Failing all of the above, he needs to get all four of his girlfriends, one posted on each corner, telling him what's happening to each wheel when he's sliding around on the wet grass. Whether and which wheels are spinning and which are not. Then he'll know.

Alternatively, there will be such a cat-fight that he'll forget all about 4x4 (for a while).

Good luck Ben and let us know how you get on. And if there is a cat-fight, photos please!

 

[Chris]

Isn't there a viscous coupling on the 90 Bob?

Chris