Hey I have a Volvo fh 12 1996,it has a d12 engine with a sr1900 gearbox
10 May 2020 21:05 #209963
The truck originally would grind very badly when selecting 1st gear.
So I decided to remove it for an overhaul
.it had two worn shoes and also the synchro was shot for that gear.
A gearbox specialist rebuilt it with good second hand parts to try keep down costs and replaced the clutch twin plates and release bearing Now being completely back together and working the truck grinds in most gears and jumps out of 2nd occasionally.
U can avoid it grinding by double clutching it and giving it extra time
Know another with same problem.......however ,it seems the plastic piston in the clutch cylinder is prone to breakage.....My suggestion was to fit a Road Ranger and angle spring clutch ,due to incredible cost of the Volvo box repairs ($30,000 quote)....His also has the Cummins motor.....Havent seen him since.
if you want to develop a Swishy like hate for Volvos ,just contact the service department.....Here s a classic I recall."Why dont you try replacing the plastic piston in the clutch air cylinder....its the cheapest repair you can do"......cost of plastic piston ..$1100.
This Volvo is a bit modern for me. Agree it sounds like clutch drag - to diagnose jack one wheel up and have a helper put it in gear and declutch; should be easy to stop the wheel from spinning. There are different specs for the FH D12 motor (from 320 to 420hp) and consequently they had different clutches. The SR1900 was matched to the 420 motor. Volvo went to pull type clutch release prior to the FH. With twin plates there is an extra chance that something was not put back right and if the rebuilder assumed it was a push type the adjustments will be arse about. It is quite possible that you can fit a generic clutch servo.