LT77 Removal Sticking clutch

[jimthesail]

Ahoy !
Following on from earlier post I am now having difficulty in extracting the gearbox for the final parting. It has about a half inch gap all round but something is 'holding on'. It is supported on a trolley jack cradle with a bar under the sump that ca be adjusted but the box naturally wants to take a position prop shaft end low, with a one inch gap at top and the original gap at bottom, indicated by the sump plate holes aligning with the holes in the bell housing. i.e. it appears broken backed. It is in kit car It has been 'messed about with'. It is coming apart, as with the end of the clutch operating push rod protruding no further than the tin spacer plate I suspect something is miss assembled inside ? Thanks in anticipation !

[jimthesail]

Having slept on it, suspected speedo cable restricting due being secure due IVA regs. but is clear. Double checked clearance all round. Removed rear support cross member as fouled when box raised. No go. However I suspect that the original reason for entering swamp has raised its head and the prob. is the driven plate jammed on the gearbox input shaft. Any other suggestions ? Will have to drill hole saw hole and remove pressure plate securing screws ! Fun, fun, fun !

[DaveEFI]

Since the clutch will have to be replaced, I'd try using an extension tube and flood spray releasing fluid onto the splines via the existing gap. Leave overnight then move the box in and out till it frees. A lever either side to keep the force at right angles might help too.

[Ian Anderson]

I wonder if the bush / bearing in the rear of the crankshaft has seized onto the gear box shaft and is thus too big to slide through the splines of the clutch plate?

Ian

[GDCobra]

Sounds like your reason for larger gap at top than bottom is that is where the weight is placing the engine and 'box. The engine wants to tilt forwards and the 'box downward at rear. Could you jack up the front of the engine and rear of box to get the larger gap at the bottom this would give a better chance of getting penetrating oil in where you want it and possibly also get access to the pressure plate retaining bolts.
Is there any possibility of being able to get a bolt through the gearbox retaining hole to pick up on a nut placed in the gap (and a thin plate to stop end of bolt going into threaded hole in engine) so you could jack the box away from the engine?
Lock nuts are thinner than regular nuts so may give you more chance. If done at top and bottom this could also help keep 'box in line with ending as you extract it.

[jimthesail]

Some crackin' ideas but you haven't heard the best bit ! Cut 30mm hole saw in bottom of bell housing and undid the 5/16" set screws by turning flywheel with screw driver. (Ratchet spanners invaluable ! Noticed driven plate centre over hanging splines ! Clue ?
Large crowbar and Plus Gas and copper hammer tapping nose of input shaft. No go. Blowlamp. Ditto ! Cut plate apart with 1mm small cutting discs. (Magic !) Used half cup gear puller. Success but very well stuck ! Looked at splines, square on shaft, tapered on plate. Wrong driven plate and by the look of it, wrong pressure plate. Some people ! The Plonker must have driven the plate on when bolting up gearbox !

[jimthesail]

'Last knockings !' Bit intrigued when replacement centre plate arrived. Spline looked the same as original, wedge shaped section. Offered up to input shaft, 'perfik' ! Tried original again, entered 3mm one way and zero the other. Suspect original was under limits and would have been forced on when bell housing bolts tightened up. If the centre spline was made with a broach, it would tend to get smaller toward the end of the batch due to wear ? Moral of the tale ! Test driven plate spline on input shaft before fitting !