i am impressed with this help thread, i reckon it'll be soved in no time, well done fellas! think of it like this maybe... if you draw a straight line coming out of the back of your gearbox and a straight line out the front of your diff, you want the two to be running parallel. never touching and never getting closer or further away from each other. good luck ange!

and just check your front wheel bearings if you have time. i had the same problem as you describe and most of it was in the front wheel bearings would you believe!

alright will try angling the diff pinion up tomorrow after work to see if it improves the situation... (fingers crossed)

im pretty confident its not the wheels bearings nor the pinion bearing as suggested before as the ute was running sweet with the a12 with no vibration prior to the conversion...

wish it was that simple but i think its my (not so) handy work thats caused it..

anyway thanks again for all the suggestions so far... just shows how good this club is..

proud to be apart of it..

thanks again
and ill keep you's posted..

Hi mate, Sounds like these guys are on the right track, but just have a quick look at the exhuast system i'm geussing you have upgraded it, I have had 2 cars with weird vibrations that stemmed from the exhuast. Case 1; a bad 3" system causing a resonance vibration that could only be felt at a certain rev range & Case 2; On a completely different vehicle at a certain speed the exhuast would just touch on the body causing a vibration and a noise (of course). May be way off track but worth a mention, good luck with it.

after angling the diff pinion up in stages i found that the vibration wasnt as bad but still present...

not as bad meaning it wasnt felt untill faster speeds around 80kph + but it was still very much there..

im gonna pull the tailshaft out and get a second opinion on the balance of it..

if it checks out ok im gonna try another gearbox as mine has play in the output shaft..

and if it gets to that while the box is out im gonna try and make some more room in the tunnel to get the box higher if i can..

any other suggestions before i pull it all apart??

give 4nik8 a call and go down to see the guys who did his... they might be able to help out with this

hey ange, how we going with those wobbles ???

what about a loose flywheel??????
stuffed unis?

if it's when your coasting, it sounds like theres some slack somewhere, when you get on the gas the slack gets taken up.

If there is no vibration when under load at high speeds, why on earth do people think that its the angle?? the angle is still present when under load?

It sounds like it may be to do with the gerabox flywheel because your problem occurs when you change gears......

thats an interesting point datsik...

and im thinking that the slack im taking up is in the output shaft of the gearbox...

it has noticeble play in it when u grab the tailshaft by hand and wiggle it.. and its not the uni's they are new...

althought the rx7 that my running gear came from had no vibration... there was no angle..
now that im running some angle on my uni's i think that is whats causing the play in the output shaft to slop around..

well thats my latest theory anyway...

im going to take the box out...
get the tailshaft tested elsewhere for balance.. get another gearbox and see how i go...

while its out ill see if i can improve the angle any furthur...

ill sort it out...
hopefully sooner rather than later

but ill get there

hey ange did you end up trying the hose clamp around the tailshaft ??? if it is play in the output shaft then a hose clamp up the box end of the shaft would really accentuate it ??

you gotta get this fixed soon i'm hanging to come have a look... never been in a rotory and reckon a datto one would be a good way to experience it for the first time

Quote:
why? well;
Basic physics of 2 uni joints on a shaft.
The description given of the angles.
The way the angle changes under load.
The fact it happens around 60 - 70 kph tells me its to do with a part that this speed is specific to. ( A flywheel of which this isnt ) A flywheel vibration would be rpm specific.
Could basically come down to an out of balance wheel. Out of balance wheels cause vibrations at specific speeds, then the vibration will dissappear at other speeds.

My bet is still on the uni's, basically from the description of the angles.