Gearbox only removal.

[midget]

Although I am well practiced at removing and replacing engine and gearbox together, and engine only operations, I have just this day suffered gearbox failure on DiD run. Hence I only need to change box, so wondering if (as I have never done this) if it quicker to follow the manuals instructions of changing box leaving Engine in situ?
I do have a pit and necessary jacking equipment ---and a spare 'box.

[JOWETTJAVELIN]

You will have to support the engine sump at the rear on a jack interspersed with a block of wood so you can let it down a little to help remove the gearbox. Drain the gearbox oil then remove the propshaft. The rest should be quite easy, you might be able to remove the crossmember if the bolts come out easily.

[midget]

Yes, I would not have considered this method if I had not recently finished a full rebuild, with new chassis. (van)
Cross member was new with new fixings-- should be a breeze. It was always planned to replace the 1098 engine and ropy gearbox at a later stage, so this has bought it forward a bit.

[kevin s]

Did ours easily enough, remove gearstick, prop and clutch linkage, support engine under sump with jack and block of wood, remove crossmember, drop back of gearbox about 6 inches (keep an eye on heater tap and fan to radiator) and support, undo box to engine bolts, pull gearbox back a few mm rotate gearbox about 90 degrees on engine and pull it off.

[pgp001]

John

Just curious.........What actually happened to your gearbox to need it replacing ?

Phil

[midget]

Gearbox was noisy since purchase with sloppy lever so was well aware of needing attention. However, yesterday it stated jumping out of third which then deteriorated to no engagement, carried on, and 2nd did the same thing, although it could be held in manually.

Surprisingly, first gear was operating normally (I thought that they were the weakest link) and of course top gear was fine.

Clutch took some stick obviously, so will replace this as well.

Thanks for procedure Colin.

[ManyMinors]

Kevin rightly suggests keeping an eye on the heater tap or valve but I have always preferred to remove this as they are easily broken when they contact the edge of the battery box
You'll have to remove the engine steady bar too

[JOWETTJAVELIN]

Forgot to say, mark the prop shaft to diff flanges before removal to ensure correct refit of the prop for balance.

[midget]

Thanks all. Duly noted.

[simmitc]

Amongst the "oh so easy", a word of caution: When you slide the gearbox backwards, you have to slide a little to disengage the locating dowels in the backplate, and then rotate the box to the left in order to clear the steering rack before withdrawing the box completely. This can be a very tricky manoeuvre. If the box is reluctant to come back and then suddenly comes free, it can shoot back, hit the rack, and shear the top off the bellhousing which puts paid to easy reconditioning without specialist welding. I've seen that happen to several people, and had it happen once to me, despite having done the job several times without incident, and the correct supports being in place. Just take care.

[kevin s]

Perhaps put a couple of overlength bolts in while you loosen the box from the engine?

Ours had only been together for a few days so came apart without any force being needed.