Transmission Rattle - Volvo d255 / Hurth

[bryan and wendy]

I have a beneteau 423 with Volvo d255 and Hurth gearbox. When cold, there is little transmission noise, however after warming up, there is a lot of transmission rattle at lower revs (1000~1400 approx) I'm assuming its the damper plate, which I plan to renew, however the gearbox has done a high number of hours, so while I plan to strip and replace anything looking worn which could cause this rattling. Does anybody have similar experience, also does anyone know where I can download a workshop manual for the Hurth HBW 150 gearbox
thanks
bryan

[bryan and wendy]

Wot no ansers? Surely somebody has had this problem?