My rear tyres dont last more than 20000km and they are completely bald as if i do burnouts everyday while my front tyres still look brand new. The rear end of the car sways slightly under normal conditions but when its raining man its sways like a boat and feels like the rear end is about to kick out any second I suspect my diff is locked because, i have replaced all the suspension parts in the rear including subframe bushes with solid bushes, hicas delete, upper control arms and lower control arm bushes but the only thing i haven't touched is the diff itself and its bushes. My question is; Is there anything i should check first before investing in a second hand TT Differential and if i buy a second hand diff, do i need to send it off to get the gears checked? Does anyone know roughly how much they are to recondition?
You would know pretty fast if you had a locked diff - turn tight at slow speed and you'll hear the inside wheel slipping and hopping.... you can't miss it! Most llikely cause for the 'sway' is poor wheel alignment or something else thats worn (Hicas rack ends / balljoints etc)
This, driving around a car park the rear tyres will be making a racket when turning due to slipping. Also a locked diff doesn't cause the car to 'sway'.
well there goes my diagnosis lol. stock toe arms replaced with replaced with adjustable AMS arms and Ball joints has been replaced i think (might check that again). Yeah i saw STORM is selling his TT diff for $80 which is a bargain, thought i might whack that in there and see if it makes a difference
If you don't sound like this when turning your diff isn't locked. https://www.youtube.com/watch?v=545Wih9JlyQ
What's the torque required to 'break' an LSD in a 300zx (ie make one wheel spin while the other is stationary). An old VLSD should be fairly weak so it shouldn't take much to jack up and turn one wheel whilst the other is still on the ground. Obviously you'd need to chock the remaining wheels well as the car would be in neutral with the handbrake off. At least that would help diagnose how locked your diff is and possibly eliminate it as the reason for tyre wear.
Scratch that as I'm not sure if a VLSD will act the same as a clutch LSD when measuring the breakaway torque. A quick read of the two threads below and it looks like a VLSD may creep a little before it locks and shouldn't wear out whereas tha clutch type will start slipping at a certain torque difference. http://www.zcar.com/forum/10-70-83-tech-discussion-forum/35112-nissan-comp-lsd-breakaway-torque.html http://www.zcar.com/forum/11-84-89-tech-discussion-forum/149360-lsd-vs-vlsd.html
What part is dangerous. Breakaway torque is around 70 ft.lb. Your wheel nuts should be tightened to 75-80 ft.lb. We aren't talking huge forces here. If you can't do a simple check like that without killing yourself, you shouldn't be doing any major work on your car like swapping a diff or even changing brake rotors.
Kenny if the suggestion below is intended as a test of the difference between the right rear and left rear, then just chock a wedge under one of your rear wheels and put flat dry newspaper and cardboard under the other rear wheel. As soon as you see some paper fly behind the car, put the clutch in or else you will jump the wheel chock. I think the same test without sitting in a jacked up car with engine running.
WTF? You use a torque wrench to measure the torque. At no time should the engine be running. No wonder you thought it sounded dangerous. Perhaps you shouldn't blindly give advice when you are out of your depth. If you read the links I posted it's explains the process quite well. 70 ft.lb is around the same at 24kg's applied to the end of a 400mm breaker bar, which is the type you can get at supercheap for $20-30. That's about how much force it should take to turn one wheel while the other is stationary. A locked diff obviously won't allow the wheel to turn. Dumping the clutch with paper under one wheel will send you flying forward unless your LSD is completely knackered.
