4x4 fault I think

Hi I have a freelander td4 03 plate I have done the 1 wheel jacked up and VCU seems to be working but when I drive up a wet feild the front wheels are just spinning no rumbles from box or IRD unit drives fine apart from the back wheels don't seem to do any work

Markw48 said:

Hi I have a freelander td4 03 plate I have done the 1 wheel jacked up and VCU seems to be working but when I drive up a wet feild the front wheels are just spinning no rumbles from box or IRD unit drives fine apart from the back wheels don't seem to do any work

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If the VCU is working and you can feel strong resistance when the rear wheel is turned, you must have drive to the rear.

Daft think could the tyers have anything to do with I have 4 Chucky colways just fitted, even in reverse the front wheels just spin I have just put a new Uj joint in as the othe 1 was donaled ducked

You say rear wheels when I tested it I done it with front wheels jacked up off the floor

VCU seems fine with back wheel jacked up and tested

So to clarify, when the only jacked up wheel is a rear wheel you apply a constant pressure to the wheel and it only slowly turns? If it's free the VCU is not working in an open circuit sort of way. Believe it or not some people sell VCUs that do not provide rear drive at all. Can you video your rear wheel up test?

Also I take it you don't have the 3 amigos?

3 amigos ? Yes wheel up test has constant resistance so VCU seems fine

How do you know the front wheels are spinning and not the back? Has someone outside the car seen this? Did they check both back wheels - as they're on a diff so its possible only 1 back wheel is spinning - although if you've got TC they should both spin.

As has been said, if you've got resistance turning a back wheel - and assuming the brake isn't binding - then there WILL be drive to the back wheels.

Yes my dad viewed it as a was driving just the front wheels spinning as it got stuck

Just read up on the 3 amigos I don't have any lights on at all just 1 break light out but no dash lights on

Markw48 said:

Just read up on the 3 amigos I don't have any lights on at all just 1 break light out but no dash lights on

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I guess resistance is not a guarantee that the VCU works if it's a dodgy unit. Any photos close up of the weld round it?

I have rarely heard of an ird failing rear drive with out making noise and generally being buggered.

Ultimately you may have to jack up all 4 corners and drive the wheels, the fact the rear wheels are not being pulled at the same speed as the front should make the VCU work and prove if you get drive, if not you can observe what's going on. E.g no drive from ird etc.

Be careful of course

I'd say the first thing to do is to jack both back wheels off the ground and turn 1. It should turn freely and the other wheel turn in the other direction. The only 'resistance' should be the weight of turning the wheels. This will prove that your brakes are not binding.

Then you need to have just 1 rear wheel up and to a proper 1 wheel up test - see how long a weight takes to fall on a bar fixed to the wheel (hub nut). Compare this to the other 1 wheel up test results to see that the resistance is 'within normal range'.

If it is, then your 4WD system is working as it should - the diff and IRD gears are in place and the VCU is transmitting the correct levels of torque. Your rear wheels will be turning if the fronts are spinning.

As roccotune says - its possible that under engine load, if the bearings are worn in your IRD (or diff) it is possible that gears will slip - but it will be accompanied with an awful lot of noise!

Ok I will get pictures of VCU welds tomorrow and when I had it jacked up with all 4 wheels off the hubs were all turning whist in gear so it may be the VCU unit

The resistance across the vcu is a sign of whether it's working or not. It's the range of this resistance that's the problem. Too much and it will put too much stress in yer transmission. To little and there won't be enough drive to the rear wheels when it's needed.

Yer don't think it has enough friction

Sounds like my bull**** freewheeling VCU I got from those ****ers at freelanderspares a few years back.

One wheel up provided some resistance, but not nearly enough. I could turn it with one hand on the tyre....
https://www.youtube.com/watch?v=qna_kdcQwLw

Which in use gave no drive to the rear....
https://www.youtube.com/watch?v=QiImCra8XUY

On normal roads, it provided just enough resistance to alter the way the car felt compared to two wheel drive, but it wasnt until the snow arrived that I realised what a load of pish it was.

Well people I went to the freelander this morning in s must feild where she is parked in reverse watching the wheels the 1 back wheel spun but the more you drive it round I lose the drive to the back wheels has to be the VCU right, I for got to mention the freelander stood for 2 years and never moved could the fluid in the VCU be laying at 1 point in the VCU ? But the nacked Uj joint wouldn't of helped the VCU unit now has a brand new Uj in it also had a new ird and gear box before I got it

Being stationary does allow the fluid to drop due to gravity but once the FL starts moving it easily mixes round. Mine sat for a year ok.

Try a one wheel up test and tell us the number of seconds. Also see if there's a name on the vcu. Has it been re-welded around it's circumference or the fill hole on the side messed with?

https://www.youtube.com/watch?v=L0ytdkWyEsQ