since auto to m40 swap i have developed a rattle/growl at 90kmh on overrun.since fitted spare m40,clutch,crossmember,tailshaft.Noise moved to 100kph,yokes in line,when i fitted rear mount carrier bracket to trans the obvious way up it seemed to stress mount,so turned it other way up.Question for gurus,which way does carrier mount to trans{not in book},what is the best way to check alignment of gearbox,centre bearing,diff?.Thanks for any light you can shine my way. Jack McIntyre.

The driveline may be out of balance.
During the tranny conversion, did you remove a short front section of driveline and replace with a longer front section to the exsisting rear piece?
If so, you should take it to a driveline shop and have it checked for balance.
Best,
Shayne.

thanks Shayne,imade up tailshaft by shortening 265 front section and fitting 240 diff flange to tranny.That way i got three large uni joints and two large flanges on 2" shaft,when problem arose i fitted other m40 and mating shaft for minimal result.Had no problems with auto trans, thats why i'm assuming it is alignment related.Tailshaft turned out excellent,have full machine shop at my disposal.It drives great but is annoying after all the effort.