alright guys i have a problem with my datto thats been hassling me since i got it started and is starting to get the better of me...

im stumped at the moment as to what to do to fix it so im turning to the datto family for some ideas... this is the last of the teething problems and its stopping me from getting my ute to the engineer so i can get it legal and enjoy it

for those who dont know its a standard 12a rotary engine with a rx7 5 speed and standard ute diff..

i have a slight driveline vibration which only occurs above 60-70kph and only when not under load..ie if you put the clutch in to change gear.. when accelerating theres no vibration... when coasting in gear theres no vibration.. only for a second when u let go of the accel pedal... if you put it in nuetral and let it roll vibration is constant..

the chap who made my custom tailshaft has looked at it and says there is a tiny bit of angle on the uni at gearbox end..

since then i have lifted the gearbox higher.. and dropped the engine slightly... this meant modifying my trans tunnel furthur.. making another set of engine mounts and gearbox xmember... and modifying my exhaust so it doesnt knock on the underside of the car...

the vibration isnt as bad but is still present...

tailshaft guy says the box has to go higher still...

now to move my box up... apart from modifying all of the above AGAIN... i will end up with a fairly big angle on the uni at the diff end....

so at the moment im stumped...

i can improve the angle of the gearbox side uni by making the engine lower... but doing this will involve recessing the original datsun engine crossmember... and making all new mounts etc.. but i havent heard of this being necessary in a 1200 with rotary conversion....

where have i gone wrong??

do i need to lift the gearbox higher and then have the angle on the diff changed to improve the uni angle's again??

im stumped... tailshaft guy isnt much help.. apart from saying box up box up...

and idea's or miracle answers to my problem before i start pulling the whole thing apart AGAIN...

thanks in advance guys and sorry for the longest post ever

ps. i bought an rx7 for the running gear and there was no vibration present when i drove that...

cheers