Bad vibration. Thinking gearbox????

[ae86 drifter]

Hey guys I've got a vibration issue when at higher speeds above 100km\h. its got me stumped.
whens are brand new and balanced,tailshaft has been balanced twice.
Its got me thinking its the t50, speedo gear has stripped the nylon gear. there is no noises or gear shift problems.
Anyone else had the same problem???

regards pete

[davew7]

Check both engine mounts and the trans mount. Use a pry bar or completely remove them to verify. If the vibration is not gear related but speed related it could also be a tire. Dave W

[ae86 drifter]

Check both engine mounts and the trans mount. Use a pry bar or completely remove them to verify. If the vibration is not gear related but speed related it could also be a tire. Dave W

Hi Dave thanks for the advice, engine mounts are trd items and basically brand new. have checked them out today. What would I be looking for with a tire as the rims are new and balanced.

[tuned86]

Sometimes tyres are just shit even if new & balanced, e.g. defected I had one of those dunlops from ebay which would vibrate at 60km+
Systematically isolate the issue. e.g. swap the rears to front. if its tyres you should feel the wobble through steering or the sound should be slightly more audible. Swap out suspect tyre for a spare.

Good luck. I once had a shitty vibration sound, stripped out everything and it one day I discovered it was the passenger seat adjustable spring...drives ya nuts.

[ae86 drifter]

true ill check it out. I've had this vibration for over two years. gotta get to the bottom of it as its driving me nuts

[Slimer86]

Tail shaft bolts all tight?

[LittleRedSpirit]

Twisted axle?

[Matt]

is it worse on acceleration / deceleration?

[ae86 drifter]

so I've had the car up on the hoist and done some rough angles on the pinion and and its way outer back. motor and box have roughly 4 degrees down from factory, and I've measured the pinion and its 2 degrees down, Meaning the parallel aren't parallel. more investigating to come. higher speeds above 115km/h.

[Sam-Q]

sounds like the tail-shaft needs the balance checked