vibration noise in 3rd gear

[Dave]

G'day,

I'm getting a deep vibration right through the car in 3rd gear only.  Usually at around 40mph or so, but slightly backing off or accelerating a little stops it.

The noise doesnt sound like a gear box problem at all, and there are no noises in reverse or 1st and 2nd.

I'll change the uni joints if need be, although i just cant pin point the problem or where it is coming from.

cheers
Dave

[mad_ozi_hunter]

gday
had the same problem turned out to be my tail shaft
jack up the car,get it on stands, start the engine, get it idling in second gear, then get under the thing with a light(helps to cast shadows)watch your taleshaft. if u have any movement up/down, your taleshaft  is either out of balance ,or warped.the factory specs allow for 0.030 of a inch movement, any more will cause vibration and eventually damage your uni joints,might be a good idea to change your yoke if it is the tailshaft,new yoke is around 89.00 at rares
cheers
m_o_h