[OVR4U] trouble shooting....again =(

[kaotik]

Ok guys...I have a problem and I'm looking for some help before I throw the car in the bin out of aggression.

Currently my car drives but feels like the clutch is slipping like crazy.

Upon first diagnosis I had no bolts in my front passenger side driveshaft so it was just flopping about...this was not the problem.

Checked the master cylinder and it was stuffed...it was pressurizing the slave and we thought it was not allow the clutch to grab properly...brand new master in and still...not the problem

I'm thinking driveline...I was thinking and when i had it on the hoist my mate turned the front wheels and rears didn't turn...
If I turned one of the rear wheels the other turned and same with the front but there seemed to be no link between front and rear...

Is this normal under no load or is this a good indication as to something beig broken???

 

[bazeng]

Something is not right.

If you turn the front, it should spin the rears from memory.

Possibly something could be wrong with the centre diff...

 

[Entaran]

I once burned out a Viscous centre in my silver one and produced results like this. I can't remember if that's in the tcase or gearbox tho.

 

[kaotik]

Ok now to settle some confusion...centre diff=transfer case??

 

[CLuTZ]

Are you sure the clutch isnt poked? What do you have in there exactly?

 

[Entaran]

Centre diff is in the gearbox. Transfer case is a right-angle drive.

 

[ONPSI]

Yeah if its your centre diff out with the box.. thats the fun right there :wink:

 

[bazeng]

Your Viscous and Centre Diff work together..

I'd say its either one of those..

Otherwise you may have a busted driveshaft somewhere without knowing it..

Alot of guys bust the 3bolt rear inside the diff so it looks ok externally but the splines aren't actually spinning..

I'd jack the car up (all 4 wheels), inspect all driveshafts.

Possibly / safely start the car and put it into gear and see if all wheels spin.

 

[kaotik]

The clutch in there now is an exedy 3 puck ceramic button...it should be holding no worries...I don't think it's driveshaft because if i spin one front wheel the other front spins...same with rear but there seems to be no front rear link...maybe it's time to get the box and transfer case rebuilt?
Any reccomendations??

 

[GVR40]

sounds like the viscous coupling inside the box.

 

[trist]

if you can do what bazeng said Possibly / safely start the car and put it into gear and see if all wheels spin.

 

[Muzz66]

crap in the slave will cause clutch slippage.it will pump up but not let the pressure out and leave the clutch disengaged.

 

[trist]

how would you fix that

 

[Muzz66]

how would you fix that

well you could just strip it down and give it a clean and flush the system or put a kit through it but for $37.50 for a new item from Meek's why bother. :thumbsup:
http://www.meek.com.au/index.php?searchStr=slave&act=viewCat&Submit=Go

 

[kaotik]

Cleaned and flushed the slave...might just change it to rule it out though
but I've noticed a clunking sound when the Clutch bites and really sounds gearbox or diff related.

I will try get access to a hoist n see if I can drive it n suss which wheels turn

 

[rob323]

All this turning wheels while up in the air is great, BUT, what "should" happen will depend if it is in gear or not. But pretty much, it will tell you nothing unless you have some limited slip or locked diffs.
If your centre diff is broken, it would not feel like clutch slippage (which usually only occurs when the torque kicks in), it would feel like you were driving an automatic car with a 6000 rpm stall convertor.

 

[bazeng]

I remember VR4rs had a broken centre diff (spider gears). He found that it went well for a bit, then slipped, then went well etc without much noise...

I believe the spider gears were broken and locking the centre and then loosening again allowing it to slip..

Have you checked the condition of your oils? (transmission / transfer / rear diff??)

 

[kaotik]

Rob!!! That's exactly wat it feels like!! U hit the nail on the head

 

[kaotik]

ok....so....
heres my list of things i have done to try sort this issue....
-New Master cylinder
-New Slave cyliner
-New hoses and hard lines
-Checked clutch and flywheel and both are fine
-Changed the entire gearbox (selects gears fine, no clunking grinding or nosies of any kind)
-Bled and adjusted til the cows come home
-put different sized push rods in the slave to make sure it wasnt too long and holding the clutch slightly disengaged

still up shit creek!

me and my mechanic are both at our wits end....
i dont think ive ever been so clueless!

 

[Entaran]

This might be a simple question but what clutch is it?

Have you tried a completely seperate clutch/pplate. Has the pressure plate died and isn't clamping hard enough?

Are you getting the "clutch" smell under accel, are the revs holding at like 3500-5000 rpm and the car slowly accelerating (kind of like how an auto accelerates at half throttle)?

If there's clutch smell and it's doing the above, your clutch physically needs to be replaced as the pressure plate has failed. It can be a simple metallurgical failure that you probably wouldn't be able to see with the naked eye.