D Type Overdrive Spline Alignment

[Josef]

I’ve got my old Spitfire gearbox rebuilt and back together and have been attempting to fit the overdrive (D type, overhauled by Overdrive Spares in Sheffield). The two sets of internal splines that engage with the mainshaft are misaligned, and I can’t make them move at all. The factory WSM says ‘use a screwdriver’. I’ve tried that, and moved out to bolting a handle to the prop shaft flange and using my scrap mainshaft with some mole grips on it. Can’t rotate one relative to the other at all. Any suggestions? I’m guessing I might have to split the case to release the spring tension holding these together?

[DanMi]

You need to get a screwdriver in and rotate the back set of splines not the front, I believe clockwise, but I would check the manual on the direction

[Pete Lewis]

Nah  dont faf around poking down inside to align the splines 

get two decent screwdrivers or levers and with the OD dropped on up as far /nearly engaged and lever the two operating piston bars to open the grip and it all free wheels into place 

keep finger out the way as it will drop quite quick   you may need a spare pair of hands to help  but this is simple dodge to pop the unit back on 

Pete

[NonMember]

I found the pre-aligning trick to be quite easy on a D-type but, as DanMi says, it's the tucked-away-in-the-back ones you need to align.

[Josef]

Yeah, the back ones move freely anti-clockwise. Everything else is impossible to move… The manual says just “Align the splines of the planet carrier and uni-directional clutch using a long screwdriver”. I suppose if I had taken the thing apart myself I guess I would’ve known what the various bits were. Oh well. It’s on now.