Help required - Can't split the engine and gearbox

[James Eastwood]

Hi there, how are we all? Cracking on with some projects in the lock down time!

I decided to put a new clutch in my Ace, because the current one slips and I've fully inspected the slave travel etc.. and that appears to be fine. The plan was to leave the gearbox in the car whilst pulling the Bristol engine, and that way gain access to the engine bay for some cosmetic work.

With the gear box mount remaining attached to the chassis, I had the engine disconnected from the bell-housing, and suspended by a hoist, with a jack under the gear box. Everything is in a straight line, and I had an even 1mm gap all around the bell housing. However engine wouldn't pull off the gear box. So I made a puller that pulled from the front suspension frame to the crank damper. I wound that up pretty tight and still nothing gave.

I concluded that the pressure plate must be stuck on the input shaft splines, so decided to remove the clutch diaphragm in-situ. I used a die-grinder to slightly open up the left hand (unused) clutch fork aperture until I had socket clearance to the pressure plate bolts, which I then removed.

Ah-hah! I thought, now the engine will pull straight of ... no it didn't! I put the puller back on.. still no movement. I thought, ok the pressure plate is stuck on the flywheel dowels (in addition to the stuck splines), so I reached in through the starter aperture and tapped the diaphragm and pressure plate car-rewards off the flywheel, but still no further separation. I can physically feel the diaphragm is loose now and the pressure plate is also 8mm car rearwards from the flywheel, so I don't think the plate is stuck on the input splines.

My conclusion is that the only thing left that could be stuck is the input shaft bearing in the flywheel. The Ace owners guide shows a roller bearing in the flywheel, so it might be possible for the outer race to seize to the flywheel, whilst the inner race seizes to the input shaft. The assembly will still rotate courtesy of the ball bearing, but it won't separate.

Please let me know any other checks I might perform. Also let me know if you agree with my conclusions ref the seized flywheel roller bearing.

Many thanks indeed.

James Eastwood, BE475

[Flyinghorse]

James ,
Having  recently split the gearbox from engine insitu  on my CRS it seems you have covered all bases regarding the likely cause of the problem( input shaft to bearing)

Barring  a silly/ obscure  problem like some unseen bell housing /starter motor/bolt or nut still being in place, or the engine steady damper causing interference  , or there not being enough lateral distance to do the box/ engine split( unlikely given you could rig a front damper puller up).

It would appear that the input shaft to crank shaft bearing is the issue, but odd the engine can be turned over , or drive shaft rotated, which would suggest some sort of friction welding at the bearing to input shaft.

I found I had to use a slide hammer to get my input bearing (  bush in my case) out  and it needed A lot of impact rather than  just a direct pull and was difficult to remove.

Sounds like the gear box may have to come out with the engine so you can get some proper leverage / impact to the problem location.

Let's us know how you get on and interesting to see if others have had this issue before and how they over came it.

I spent a day last week removing one stubborn front disc from my Volvo XC60 and that was just rust between the disc and axle flange so amazing what can hold things together- I resorted to a 4lb sledgehammer from behind and it still took patience , soaking in diesel, chiselling the rust  etc

Good luck
Graham

[James Eastwood]

Graham, thanks for the reply.

I gave the home made puller another couple of quarter turns, whilst then using my electric hoist to take the engine up and down an inch each way and it then yielded.  :)

It was indeed the flywheel input shaft bearing inner race that had seized to the input shaft. I think the diaphragm and pressure plate had been aligning the bearing, and removing them in situ then allowed the 'jiggle' I gave it second time around to go straight  to the bearing and loosen it.

What a relief to have it all safely apart. We don't believe the clutch has been out since 1970.

I've got some clutch questions for the forum, but I think I will try to find the old clutch thread and add then on there to keep all the clutch component info in one place.

[Flyinghorse]

Thats good news!
I had a debate with a fellow AC member about fitting a bush or a bearing and as mine (CRS) came with a bush I put a bush back in.
The discussion at the time was it was a very rare  occurrence that the bearing race packed in.

I would check your crankshaft end float is ok if this setup has been running incorrectly for a while -other likely issues could be worn synchros if the input shaft has been turning and not stationary due to being gripped by the input shaft bearing, but you would have noticed that driving the car with messy/crashed gear changes. Also the input shaft needs checking for any wear /damage.
Theres a few forum threads about substandard clutch release bearings (Carbon breaks up), so a few things to watch out for.

By the sounds of things you are on top of these sorts of issues.

I did wonder when putting it back if the gearbox will need to be loose to line everything up correctly.

Graham