Tailshaft & Diff hitting bodywork

[someguy360]

Hi Guys.

My VS (Live Axle sitting on Superlows) has recently developed a knock from the rear end when going over small bumps in the road/heavy acceleration.

Got the car off the ground and found this:

Tailshaft hitting body


Axle seems to be hitting exhaust:


Anyone got any ideas what could be causing this?

Was thinking maybe the bump stop is worn or maybe upper trailing arms?

Any suggestions?

Thanks

[ari666]

lol, if your diff is getting close enough for the yolk to hit the floor... you got serious problems. i'd bet its just your exhaust pipes hitting the diff. loosen the u-bolts and turn the exhaust a bit to give it a bit more clearance.

[someguy360]

Good advice as always ari :P

will adjust the exhaust over the weekend as I needed to do it anyway as the tips are out of allignment and looks stupid haha

I did a search and alot of people have had the issue of the yolk hitting the floor on live axle (mainly in VN's) but I can't seem to get a clear answer on what caused it....some say trailing arms (not sure if that would be upper or lower) and some say bump stop.

Anyone got any insight?

[BowTie]

No easy guesses.

It's possible to take each trailing arm out one at a time, clean, inspect and refit.

It's probably a combination of wear on the four trailing points/bushes.

You will be able to visually see which ones are stuffed and go from there.

Upper trailing arm bush failure should make the yoke dive where as lower bush failure should make it rise.

I would start with the lower arms first, one at a time. Most likely the lower rear bush that mounts diff to trailing arm.

[someguy360]

No easy guesses.

It's possible to take each trailing arm out one at a time, clean, inspect and refit.

It's probably a combination of wear on the four trailing points/bushes.

You will be able to visually see which ones are stuffed and go from there.

Upper trailing arm bush failure should make the yoke dive where as lower bush failure should make it rise.

I would start with the lower arms first, one at a time. Most likely the lower rear bush that mounts diff to trailing arm.

Thanks mate, will inspect over the weekend.

Do I need to take them somewhere for new bushes to be pressed in on the lower arms or can I do it myself?

[BowTie]

Yes, if they need to be replaced, source the parts and get your local mech to press them in for you.

Do the labour youself and it will be cheap.

[someguy360]

Well got under the car this arvo and had a play.

the upper trailing arms are knackered (everything else looks ok) but because the trailing arms are shot I can get a fair bit of play when shaking the diff around.

Will replace them and hopefully that will fix it

[ari666]

i am amazed you can get that much movement! especially when there is that stop on the floor just avove the diff... those control arms must be faaaaaa ed

[someguy360]

Well just moving it with my hand I can't get that much movement but there is definitely a fair bit of play there so I am assuming when the stresses put on by driving and bumps can move it more than I can.