VCU again...

Sorry if I started a thread about VCU again. I have read the other forums about VCU, yet I'm still confused. I don't know if my VCU is really knackered. After a drive, and had my car parked, I hear a ticking sound underneath near the VCU. I just don't know if its coming from the VCU. I tried to do the tippex test, but have no idea if I marked the right place, co'z what i did was marked a line in the 2 black plates located in the middle). I drove the car for many miles, doing full locks, then checked it and still in alignment. I also did jack one rear tyre and tried to turn the wheel, and it ain't moving. ( I unlocked the hand brake and gear in 1st, turn the wheel using tyre wrench in one nut, is this right? What does UJ mean? where is it located?)

The rear tyre seems to have no worn marks, as if it is being dragged. When I do full lock on reverse and forward, the car doesn't stall.

Also, how will I know if the IRD had been damaged? I checked the oil in the IRD. Its too black and thick ( is this normal?).

It is best if someone can give me a diagram of where I shall mark a line for the tippex test.

Thanks alot!

Tippex goes on the small shaft going into the VCU at the front and on the next larger hub, the two larger hubs rotate together, the one with the four fixing studs at the back being the vibration damper unit. The 'ticking' noise you hear I would venture to say is the exhaust cooling down , they all do that. How much or how little the car should drag ( thus determining the condition of the VCU ) going backwards or forwards is the subject of much debate right now. Yours does'nt sound to bad by your description. It is very hard to turn the rear wheel and do the test. UJ 'universal joint' on the prop shaft. Hope this helps.

Thanks for the swift reply mate! checked the car as soon as I have read your reply and did again the tippex test. i marked a line on the whole thing, from front prop shaft to rear prop shaft. The mark from the front prop shaft upto the small shaft before that black hub are still aligned, but is not aligned with the mark from that two black hub upto the rear prop shaft ( the mark from that two black hub upto the rear prop shaft is aligned). So there are now two misaligned lines. Hope you got what I'm trying to explain. Does this mean my VCU is alright?

How bout with my IRD? I removed the bolt underneath it to check the oil. Found out, the oil is black and oozing out slowly as i remove the bolt. Is this normal? Does the oil in it needs changing? Pls bear with my queries, just bought the car and having a second thought after reading the threads in here.

Thanks

Reet earthling if you do the willow test [tipex] your best to spin the wheels ,a wet golf course is best for this test ,now if they go outer line . . .fine [could still be in 2 wheel drive [mondo mode] if they dont move ,get it re checked a s a p. . . .as fer yer oil in ird , if yer going to change it ,only use the correct stuff. . . run motor fer 10 miles , and drain it [mind out as its very very hot],put drain plug back , pour in 1.1 ltrs of correct stuff. . . .job done [oh worth fitting new washers]

Lets get something straight here, the tippex test everyone goes on about will test to see if the VCU is seized solid, but a VCU can still be knackered even if it slips. The amount the VCU slips, and hence the amount of torque it delivers, at certain revolution speeds decreases as the fluid inside it degrades (usually knackered by 60-70k).

I know this doesn't help you determine if your VCU is knackered, but its something people need to realise. The best way to see how good/bad it is to try a car with a known good VCU and reverse it on lock/jack the wheel up test. The only sure way is take it off and put it on a test jig, but i only know one place that has one of these.

If the IRD isn't cloncking (in reverse to start with) , vibrating or locking up then it is still working OK. It doesn't mean it hasn't been damaged by the old VCU, but if its not broken, leave it alone, If the IRD goes later, it costs the same to replace a worn IRD as it does to replace a totally sh@gged one, so you have nothing lose

Yup Austen - yu is correct - but if the VCU fails in the "no-drive" way it is annoying, but wont screw up your entire drive train like it will if it siezes solid.

it never does any harm to check.

hi guys

what is the correct oil for ird & what is wrong if it clonks ni reverse

ggroenm said:

hi guys

what is the correct oil for ird & what is wrong if it clonks ni reverse

Click to expand...

75w-90w gear oil

Clonking can be caused by a few things, but one of the classic IRD failure noises is a load clocking noise when coming on and off the power, which is worse in reverse and on lock. another Clonking can also be heard when the rollbar bushes are buggered and you drive over uneven roads, or when the lower engine steady is worn, to name but a few

Check pics of vcu, the two yellow marks line up to start with. (other mark at bottom of prop from previous test. Rear of car is to left of pics. UJ or univesal joint is left of mounting bracket in second pic a cross shaped joint with 4 bearings one behind each circular cap. (one can be seen in pic.)