Prop Shaft, Diff and Gearbox

[david.g.chapman]

I was in the process of checking the rear UJ on the prop shaft of my +2.

After taking off the prop shaft flange bolts I expected the shaft to come away easily, but instead it appeared to under slight compression. It seems that the diff to chassis torque rods are compressing the whole drive train slightly. After loosening the torque rods off there was enough play to raise the prop shaft up to half-clear the diff input flange.

I could then move the UJ enough to check it -OK

Is this situation normal? ( I was hoping to position the prop shaft a couply of millimetres back to give the gearbox output oil seal an unworn section of shaft to seal on).

Also, when I do need to remove the propshaft, it does not seem possible to move it backwards past the diff to disengage it from the gearbox. The diff is about 6 mm off the chassis floor, and even if I lowered the diff, it does not look like enough for clearance. Am I missing something here?

[Hawksfield]

No this is not correct, there is a spline at the other end of the shaft in the tail of the gearbox, this should have clearance to allow movement of the rear suspension in relation to the engine and gearbox.
Check that all is fitted correctly ie engine, diff, etc.

Good luck

[jimj]

No, THAT is not correct either. The diff. remains stationery, bolted to the chassis, relative to the movement of the rear suspension. The engine and gearbox will move though, within the confines of the flexibility of the mountings, so the prop shaft shouldn`t be in compression. As you say; your diff. torque rods must have been pulling the diff forward.
I don`t think that you can remove the prop shaft rearwards without first removing the diff. or at least unbolting it and moving it to one side.
Jim

[david.g.chapman]

Thanks for that.

I realised after I posted that the diff could be moved to one side - so that's cleared up.

The car has been running OK like this for the last 9 years, but I agree that the prop shaft input shaft from the gearbox should move a little (a millimeter or so). No more than this as the diff is quite well retained by its rubber mountings.

I will check the components on the torque rods - there is a nut, then a washer (like the base of the front shock absorbers) then a rubber bush, then the diff eye, then another bush, and finally the fixed flange of the torque rod itself on the car at the moment.

I can always add an extra shim on each side to bias the diff backwards, and will aim for a millimeter of float as I have said.

Dave Chapman.

[david.g.chapman]

Just to round things off, the torque rods should be fitted with a rubber bush on the torque rod flange, then a "cup" washer with a large hole (about 12mm dia), then comes the diff eye, then another washer with a large hole, then another bush, and then a final washer with a smaller hole to clear the thread on the rod, and then a nyloc nut.

It's actually in the workshop manual but I was too daft to notice it before .

There was a good 5mm of clearance when I moved the propshaft away from the diff input flange. Everything is now assembled.

Dave Chapman.

[Hawksfield]

I assure you that all the suspension and engine/gearbox move including the Diff as they are all installed on complient rubber, the spline on the gearbox tail is there for that reason The torque bars are to increase rigidity of the diff as you state. the propshaft should not be hard up against the diff flange check it out.