Grande Centre Diff Lock Problem

[1coolbanana Avid PP Poster! Find all posts View Profile Close 1coolbanana]

Hi guys, hoping someone can shed some light here.
Vehicle is a 2003 Grande and today when using the transmission centre diff lock a strange thing is happening.
As soon as I engage it, everything is ok pointing straight ahead but as soon as you turn the steering wheel it feels like applying the brakes on the front and sounds like tyre rubbing on metal but nothing is.
The closer you get to full lock, the more the front tightens down and locks up and makes more noise.
straighten the wheels and it lets go or turn off the cetre diff lock and its fine.??? :?


Any clues would be appreciated.
Cheers

[Guest Close Guest]

Are you on bitumen or a very hard packed road?

Sounds simply like diff binding caused by locking it all together..

Mine does it too. But not off road where the wheels have limited slip due to the surface not being as grippy.

[ratsack Member Find all posts View Profile Close ratsack]

I really hope you aren't using the centre diff lock on a grippy surface... If so, goodbye drive-train.

[1coolbanana Avid PP Poster! Find all posts View Profile Close 1coolbanana]

Nah, on steep and loose firetrail and it really feels like its on the brakes and the sound of (the nearest thing I can think of) rubber against metal!

[ratsack Member Find all posts View Profile Close ratsack]

Maybe a CV on its way out or a CV boot that's stuffed? I'm only just starting with all things mechanical (real cars are very similar to RC cars though) but that's where I'd start looking.

[kav Avid PP Poster! Find all posts View Profile Close kav]

Hey mate , you've got me stumped , are all your slip shafts greased . Only other thing I can think of at the moment is are your brakes ie. traction control working properly . Although this shouldn't have too much to do with it ?

[Guest Close Guest]

Grande Centre Diff Lock Problem

Have you tried in a sand situation on flat ground?
Bindup can do weird things..

I had mine a couple times on dirt and it was very obviously binding to the point we had to disengage.

It sounds still like a binding or cv situation.. Certainly NOT electrical.

[1coolbanana Avid PP Poster! Find all posts View Profile Close 1coolbanana]

Sand....No I havent lately, I have many times in the past and you soon enough know when to turn it off.
CV's, boots etc all look good and no issue exept when the button is pressed.
Im going to have a crawl around underneath, pump everything full of grease tomorrow and take it down to the softer bits of the trail but its all quite steep, soft dirt and gravel.
I thought maybe traction control error applying the brakes at the wrong time but the lights arent coming on and it doesnt feel like that.
See what I can find out.
Cheers

[Guest Close Guest]

I still think its simply binding up..
Mine has done it at times when I would expect it to slip, but it doesn't..

[1coolbanana Avid PP Poster! Find all posts View Profile Close 1coolbanana]

Couldnt see anything obvious while underneath, everything looks in good nick!
Took it down the trail this arvo and it was starting to bind and feel like the brakes were coming on in a straight line.
Tried to turn the diff lock off and it wouldnt go, then a big "CLANG" and it let go.
Got out of there and back up to the shed, cant find anything wrong, comes on, goes off!
Ill have a fool around again tomorrow and have a look in the manual to see how it all works.
Had to take the missus out tonight and seems to be driving ok for now!

[Davis Dieso Junior Member Find all posts View Profile Close Davis Dieso]

Its perfectly normal 1coolbanana. When you lock the centre diff lock, you tie the front and rear diff to turn at exactly the same rate. As the vehicle turns, the front wheels have to go around a larger arc than the rear wheels, so have to turn at a faster rate than the rears. That is the job of the centre diff to enable that to happen, the same as the front or rear diffs do (allow left and right wheels to rotate at different rates). So, in locking the centre diff, the front and rear drive shafts fight against one another essentially giving the feeling the brakes are coming on. The tighter you turn, the worse it becomes and the harder the ground, the worse it is. Serious damage can occur during axle "wind-up". Never lock the centre diff on bitumen/concrete. The big "CLANG" you describe when disengaging is that "wind-up" between the front and rear tailshafts releasing the energy. To release the energy before disengaging, drive the vehicle backwards for a metre or two or three to unwind it.
Hence, only engage the centre diff lock on very slippery ground, mud, loose gravel, sand etc. Thats its purpose.
Hope that helps.