Symptoms of bad transfer case?

[Guilt-Toy]

So i got a similar issue with my gts-4

 

When i try and turn into a car park or a sharp corner the whole front and rear lock up and you can hear the tyres skipping.

 

Have bleed the system - no change.

removed rear diff and checked diff ratio,  4.363:1 

removed front diff cover checked diff ratio 4.363:1

front diff behaves normal when spinning wheels or the input

remove shaft from transfer case to diff and issue goes away.

 

Is there any other things you can check?  before i remove the gearbox and change the transfer case.

 

cheers

[Guilt-Toy]

Found this.

 

http://www.gtr.co.uk/forum/144368-transfer-box-locked-4wd.html#/topics/144368?page=2&_k=gv0691

 

4wd could be locked on causing this issue

[TXSquirrel]

Still haven't bled the system, but a new symptom just occur.  

Took my car out for 20 minutes around neighborhood, kept under 4k rpm and under 5 psi, only a short cruise.  Drove back into garage and turned ignition off, then I heard a fairly loud electric hum in the trunk area that kept on for another 5 seconds, after engine already off.  

Could that be the electric pump or solenoid for transfer case?  It definitely didn't sound like fuel pump.

[TXSquirrel]

Finally after three separate shops had looked at the vibration and grinding issue, the conclusion is that my car has a fairly aggressive front LSD.  So rather than vibration or grinding, it's actually bad LSD chatter amplified by incorrect differential fluid not allowing any slip.

The recommendation is to add limited slip friction modifier, which should be a simple and economical remedy.  So I'm going to research a little more on friction modifier and see if that really helps.

[TXSquirrel]

A quick update.  The vibration and grinding issue has been fixed, and the problem was indeed with the front LSD.

Initially I had the front LSD drained and filled with Redline Heavy Shockproof, and it just made the issue worse.  So I contact Redline (which by the way has excellent customer service,) and they recommend adding some of their own brand of LSD friction modifier.  To my surprise it works like magic, and I very much enjoy driving my car again.