Excessive play in transfer box KZJ90

[diggerdave]

That's about all you can do, really. I would check for leaks and the condition of the oil as well - which should be clear.

If it looks like this, leave well alone .

View attachment 101673

Bob.

OMG

Will try to avoid

 

[BobMurphy]

OMG

This was the inside . . . . .



Its what happens when you go wading in muddy streams when the front propshaft oil seal and bearing are shot .

Bob.

 

[Shayne]

What do your lower wishbone bushes look like Dave ?

 

[diggerdave]

What do your lower wishbone bushes look like Dave ?

I would expect them to be past their best as I expect they're original but they're visually fine and no play at all. Why, have you got a theory ?

 

[Shayne]

No not a theory but swmbo has spoken "you have 7 weeks and we go on holiday for 5 weeks so what are you messing with my truck for" , so i've put everything back together and was just refilling the diff when i noticed mine look shot .
I went for a drive trying to convince myself that the shot bushes might have something to do with it and couldn't , but like with the inner cv google seems to think its a likely suspect ?

 

[diggerdave]

I whipped off the front prop yesterday to change the rearmost UJ which was a little graunchy. I took the chance to actually measure the freeplay with the centre diff locked between the front output flange (rotated by hand) and the rear output flange (held steady with the other hand). I put paint dots on the outside radius of the flange at its lowest point at the extremes of freeplay (using my third hand ).

Measured between 8-10mm freeplay. Now that doesn't sound a lot written down, but it feels like quite a lot when actually under the car. Question is, what is acceptable? To my mind that figure is too much and it would certainly account for my driveline shunt... I think!

 

[diggerdave]

Shayne, I faced the same problem before my recent rip to the Pyrennees. I shelved the driveline shunt issue till afterwards because, like you, I don't think it is a sign of imminent failure (famous last words from history #2 ).

I think that you can adequately test the wishbone bushes using a pry bar.

 

[Shayne]

They need done regardless so with the way things stand i might a price from a garage .

I just tried both trucks locked and low in first gear , parked not jacked up and both have maybe 6mm of play looking at the outside edge of prop flange .

 

[diggerdave]

Did you have the front prop removed (or rear)? Otherwise the range of movement might be limited by the diff at the other end. In which case you'd be feeling the limits of the diff backlash not thefreeplay in the t box (which might be more).

 

[Shayne]

I'm not sure if i have said it earlier in this thread but the problem i have is in a D4D Colorado with less than 100k on the clock and the general condition of this truck suggests it has had a very easy life unless of course it's done a lot of towing ?

 

[Shayne]

Both trucks are parked ready to drive away i was just pointing out that a fair amount of play is usual .

 

[diggerdave]

Fair enough: I should have realised you meant both your 'shunty' truck and the 'non-shunty' truck are the same, and yes, my freeplay doesn't seem a lot more than that. I'm going to see a second hand transfer box tomorrow, so I'll be interested to see what the freeplay is on that.

If its similar, either I'm on the wrong track and the fault is actually in my front diff, or the second hand one is shot too! Or, potentially, the freeplay is fine as measured by hand but there is a fault in the transfer box that only shows itself under load...

 

[Shayne]

I'm thinking diff or transfer too and i'm kicking myself now because i could have spent the time wasted this week swapping the T-box from truck to truck which would have given me a definitive answer

 

[Shayne]

Lay in the bath trying to imagine how all the internals work when i realized the front diff must be something of an automatic gearbox and it's not engaging as it should . With this my latest theory in mind google very quickly came back with this http://www.roughtrax4x4.com/front-diff-inner-needle-roller-bearing.html

 

[BobMurphy]

Shayne,

Does the D-4D Colorado have an A.D.D on the front??

If so, how is it actuated (I've never seen one, I thought all LandCruisers were permanent four-wheel drive) ??

Bob.

 

[Shayne]

No Bob its the principle rather than the actual part in the post above i'm thinking about .

I think the surf's had optional 4x4 but used the same or very similar front diff to the collie . An electric actuator was fitted as standard to engage or disengage 4x4 .

I can't find any pictures to help me weigh it up but with our permanent 4x4's with power going to the wheel with the least traction i would imagine there must be some sort of engage/disengage action going on in there automatically .

an aftermarket front difflock must interfere with this auto action ?

 

[BobMurphy]

I can't find any pictures to help me weigh it up but with our permanent 4x4's with power going to the wheel with the least traction i would imagine there must be some sort of engage/disengage action going on in there automatically .

My understanding is that the front diff is just a simple thing - like that at the rear, consisting of a crownwheel & pinion, a diff cage with two or four pinions and a couple of conical gears on the end of the half shafts engaging with the pinions.

The two driven wheels are in opposition - jack the front up and turn a wheel and the other turns in the opposite direction. They can't do this on the road so both wheels (and the whole assembly) turn in the same direction as the crownwheel.

If the forces acting on the wheels is unbalanced (as when cornering) the pinions rotate, thus allowing the half shafts to rotate at different speeds - while the wheels are still rotating in the same direction and while they are receiving the same torque.

Nothing engages/dis-engages. Its a brilliant system, I wonder who first thought of it .

There have been developments of course, Limited Slip Differentials limit the free movement of the half shafts relative to each other and Torque-Sensing (Torsen) diffs that do something similar through gears rather than friction plates. I don't think a 'Collie' has these .

Bob.

 

[Shayne]

OK so typical open diff - so how about pinion bearing gives up wearing on the crush sleeve making all the very tight tolerances in there kaput . Would it keep working until you eventually shredded teeth ?

 

[StarCruiser]

OK so typical open diff - so how about pinion bearing gives up wearing on the crush sleeve making all the very tight tolerances in there kaput . Would it keep working until you eventually shredded teeth ?

I would imagine, what is more likely, is the scenario if mismatched tyres on the same axle causing the bevel gears in the diff to work more than they should. Add to this a low level or contaminated oil, and you start to get wear on the simple bearings of the bevel gears. But would it give you the shunt? Possibly, more likely the CVs. It's a case of Jack it up and lock certain bits then turn wheels and see.

 

[Shayne]

I should put this to rest as i will be doing nothing to the truck probably until September but i can't help searching the web and so far it seems diagnosing diff faults without dismantling it is impossible .

Out of curiosity i jacked up the front end of both my trucks this morning selected LL and first gear just to see how far i could turn the passenger wheel before the drivers wheel joined in . Guestimate is 10mm on my good truck while looking at the hubcap and more on the problem truck though i hesitate to say how much more because i don't think it's 20mm .