Vcu testing

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74
Location
Wiltshire bulford
So I've looked at the vcu testing threads and I'm trying to tie down which is the best to apply? I've just done a few miles in the hippo on relative straightness, pulled over and physically felt the vcu and it was cold! From what I can make out this is a good thing. Is it? Is it a worth while test? Came back the same way 'off road' (mild easy crispy green lanes) and the same result! cold.

Another one to 'look' for so I've read, is to check the tyres for wear on every second tread, is this true/useful?

I've tried manually turning the props and it rotates slightly (maybe 2-3mm), is this normal?

All the tyres are the same make and size.

The rear viscous support bearing was replaced in September this year?

I can hear I little wine whilst driving (all gears and neutral) which I think is tyre noise as it gets more high pitched when on freshly laid road surface.

Freelander td4 05 plate 71000k.

All this in mind, do I have anything to worry about? Or do I get digging deep in the bottomless pit that is the pocket?

Cheers,

P.s I'm fairly inexperienced at all this so bare with me :bounce:

Mike.
 
So I've looked at the vcu testing threads and I'm trying to tie down which is the best to apply? I've just done a few miles in the hippo on relative straightness, pulled over and physically felt the vcu and it was cold! From what I can make out this is a good thing. Is it? Is it a worth while test? Came back the same way 'off road' (mild easy crispy green lanes) and the same result! cold.

Another one to 'look' for so I've read, is to check the tyres for wear on every second tread, is this true/useful?

I've tried manually turning the props and it rotates slightly (maybe 2-3mm), is this normal?

All the tyres are the same make and size.

The rear viscous support bearing was replaced in September this year?

I can hear I little wine whilst driving (all gears and neutral) which I think is tyre noise as it gets more high pitched when on freshly laid road surface.

Freelander td4 05 plate 71000k.

All this in mind, do I have anything to worry about? Or do I get digging deep in the bottomless pit that is the pocket?

Cheers,

P.s I'm fairly inexperienced at all this so bare with me :bounce:

Mike.

Ignore the ? On the viscous support bearing bit? :fighting2:
 
So I've looked at the vcu testing threads and I'm trying to tie down which is the best to apply? I've just done a few miles in the hippo on relative straightness, pulled over and physically felt the vcu and it was cold! From what I can make out this is a good thing. Is it? NO! Is it a worth while test? YES Came back the same way 'off road' (mild easy crispy green lanes) and the same result! cold.

Another one to 'look' for so I've read, is to check the tyres for wear on every second tread, is this true/useful? IT HELPS

I've tried manually turning the props and it rotates slightly (maybe 2-3mm), is this normal? IMPOSSIBLE TO SAY

All the tyres are the same make and size. NEW ON BACK?

The rear viscous support bearing was replaced in September this year?

I can hear I little wine whilst driving (all gears and neutral) which I think is tyre noise as it gets more high pitched when on freshly laid road surface.

Freelander td4 05 plate 71000k.

All this in mind, do I have anything to worry about? ALWAYS Or do I get digging deep in the bottomless pit that is the pocket?

Cheers,

P.s I'm fairly inexperienced at all this so bare with me :bounce:

Mike.


Do the test!
 
Always fit new tyres on the back.

I was under the impression it only mainly got hot when under load? I.e loss of traction for example? Causing the fluid to go gel like and stiffen up transfering the drive to the rear wheels. Driving normally (even though in 4wd) predominately use 2wd right?

Forgive my ignorance, as I said, not very experienced :speakenglish:
 
Cold could mean it's open circuit too, like one of them useless vcu's which don't allow drive to the rear wheels.

Temp is a good general test as it gives an idea if the vcu is being over worked. More work means higher temp, until it reaches a certain temp when it's considered "seized". It's not actually seized in a bad way. It's just locked up as it's been pushed to activate due to differing prop shaft speeds (front to rear) or a spinning wheel like oft road. Locking up is a good thing, but not whilst driving on a tarmac road as this will potentially put more stress into the transmission.

I've never come across results for a cold vcu after a drive. If we keep testing then we’ll find out if cold vcu's do exist and they're not a problem. Try the One Wheel Up Test to confirm if your vcu is permanently seized or open circuit. Also tell us what speed you were driving at and the distance prior to the Turnip Test (measuring temp of vcu).

EDIT: Having said that mine felt cold at 8 degrees this morning but the air temp was -3 degrees. Usual short distance so it's not a concern for mine.
 
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Stone cold means its doing nuffink! By design it will always do summfink, so should get warm, not hot, in general driving! You need to decide how cold or not it is?! The one wheel up test works well.
 
Cold could mean it's open circuit too, like one of them useless vcu's which don't allow drive to the rear wheels.

Temp is a good general test as it gives an idea if the vcu is being over worked. More work means higher temp, until it reaches a certain temp when it's considered "seized". It's not actually seized in a bad way. It's just locked up as it's been pushed to activate due to differing prop shaft speeds (front to rear) or a spinning wheel like oft road. Locking up is a good thing, but not whilst driving on a tarmac road as this will potentially put more stress into the transmission.

I've never come across results for a cold vcu after a drive. If we keep testing then we’ll find out if cold vcu's do exist and they're not a problem. Try the One Wheel Up Test to confirm if your vcu is permanently seized or open circuit. Also tell us what speed you were driving at and the distance prior to the Turnip Test (measuring temp of vcu).

if i do the wheel test, it moves i take it that its a good thing? and if it doesnt move, bad thing? (seized)

was travelling between 40 and 50 mph.
 
if i do the wheel test, it moves i take it that its a good thing? and if it doesnt move, bad thing? (seized)

was travelling between 40 and 50 mph.


Not really
It just means you have, prospectively, a VCU with no drive.
Moving is better than not moving, but it is the rate of change which is the critical bit really.
 
if i do the wheel test, it moves i take it that its a good thing? and if it doesnt move, bad thing? (seized)

was travelling between 40 and 50 mph.
Movement v's length of bar and amount of weight on the end gives us a torque in newton meters, which could be used as a comparison. If loads of peeps tested theirs and put up results we could see what the average result is, and ponder (argue) over those that int. Perhaps draw a rule of thumb.

Edited me post above. My vcu felt cold this morning at 8 degrees but air temp was -3 degrees and I'd done my usual short drive so that dun't worry me on my hippo.
 
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