andrew_v

Im sure loads of people other than myself have come across a shudder in their VN-VS commodore before, due to the centre joint in the tailshaft being worn. I was quoted around $800 for a full rebuild on my tailshaft which included a new centre joint, universals, and a balance. That seems awful steep yeah? Anyway, I was thinking, what is to stop you from having a 1 piece tailshaft made up and leaving the centre joint out all together? Has anyone done this in a VN-VS commodore before and if so, a Ute?

Why do commodores even have a two piece tailshaft?? Only reason I can think of is so that the universal joints arent on to much of an angle all the time???

__________________

ferret

my bro in law looked at it and the engineering mob up here said it stresses your uni's too much so I think your on the money there bud.

__________________
I'm looking for a 308 red block, please PM me if you know of one. 40 thou over is still good but please no complete donks.

http://i229.photobucket.com/albums/e...erret/sig1.jpg

Daryn

Having a 1 piece throws the harmonics or something out I'm pretty sure although correct me if I'm wrong. Wabbs and I looked into this for my ute and decided to stick with the 2 piece. Hardy Spicer are shortening mine to suit the six speed and they reckon it will handle up to 600hp.

JUICED

they also did it for a safety reason so that if your driving down the road and your front uni gives way, the tailshaft won't bite into the ground and flip the car on its lid.

ferret

didn't myth busters prove that wrong? dunno could be wrong

__________________
I'm looking for a 308 red block, please PM me if you know of one. 40 thou over is still good but please no complete donks.

http://i229.photobucket.com/albums/e...erret/sig1.jpg

JUICED

hahhaa, i donno, probably knowing them. holdens thought was there though i spose

76lxhatch

Well they proved their car wouldn't flip over, but it still wasn't pretty...

andrew_v

Whats that setting you back if you dont mind me asking???

__________________

Daryn

Just went back and checked something.........its also to do with the pinion angles as well. Hardy Spicer say you can use a 1 piece if you're also using a 9 inch, but for VN onwards, they say to stick with the 2 piece.

I think we worked it out to be around the $200 to $300 mark. That's with heavy duty universals etc. I'll know more when we actually go to order it in a couple of weeks.

wabbit

BRAIN MATTER FAILING.

that price sounds familiar, Daryn. The main point that they stressed was to balance it correctly. that and the actual cost of the unis is the largest part of it.
the pipe used costs bugger all.


i was concerned about the size of the tailshafts, but the specialist at Hardy Spicer reckons that they are as strong as a single shaft 4 times the diameter with equivilant wall thickness. all to do with the shorter shafts.
less twist, yada yada, etc...

also, a lot of harmonics are cancelled out by the centre bearing.
picture a pair of universals rotating at 7000 rpm and moving backwards and forwards about 8-10 mm, 14 000 times a minute. this is what happens with a single shaft- you have to respect the universals when you think about how much work they actually do.

the centre bearing splits the angle between the 2 unis, so they don't have to work as much. they still cycle 14000 times a minute, but a lot less than with a single piece.

also, with a single piece shaft, the pinion angle is critical to reduce haqrmonics (there's that word, again). BUT, the pinion angle is only correct some of the time. assuming you have suspension, of course.

i've tried to put into words what the driveline specialist at Hardy Spicer told me. Some of it may be wrong or misinterpreted by me.
I'm sure somebody will correct any errors.

__________________