When I disengage the clutch/pop the gearbox into neutral at speed the sound remains. Final drive bearings?
This isn't going to be that expensive - a replacement gearbox (and upgrade to a 5speed) is going to cost $125 for the box+labour, and a replacement hub with a decent bearing is ~$40 NZD. (this was the last year they used this motor in the pulsars, 1987 in the n13 they went to the CA motor, mine's an E13 :/ )
There is a cyclic grinding/graunching? from the drivers front wheel under braking (noticeable and embarrasing under 50kph) as well so maybe related? Turning the rotor with the wheel off the car I see no wobble/warping in the disc though.
Turning the front drivers side wheel when the gearbox is in neutral on a jack, the driveshaft has a lot of play at the box end (~1/25th of a turn before moving the final drive in the box) and it clunks when i move it enough to rotate the final drive. Not clunky on further rotation though. :S
Turning wheels by hand there is no bearing noise at all and there are receipts for all the bearings being replaced ~10-20,000kms ago.
Thanks for your suggestions guys.
(oh BTW I'm tempted that if I can find $300 I'm going to drop an E15 and the attached 5spd manual in this car from a Langley (up-spec pulsar) in the local pick-a-part. 200cc increase and an extra gear for $300+ a weekend. yay?)