Rover V8 sectionHi Mark,
It now seems that in fact, the release bearing is jammed against the gearbox. Worth checking that there is clearance between the lever and bellhousing, it would be a shame to fix the 1st problem only to find there's still a problem.
OK, we know what's needed - you found that out yourself. The gearbox has to move away from the engine, far enough for the release bearing to become free.
Three issues here.
1. We don't know how far things have to move
2. As we move the engine and gearbox apart, it will start moving the gearbox shaft out of the spigot bearing. See what I mean?
3. If we move things very far apart, the engine and gearbox mountings will not line up correctly.
Look at these.
1. I'll guess at say half an inch. Perhaps 1/4 inch might be enough - but you have to allow for clutch wear in the future. As the clutch driving plate goes further in (forwards towards the engine), the release brg will move further out (back towards the gearbox). So 1/4 inch is worth trying, 1/2 inch would be nicer.
2. Often, the gearbox input shaft goes right through the spigot bearing and a bit of it sticks out into a hole in the end of the crankshaft. If this is the case, you can safely move the engine and box apart and still have full engagement, see? After that, as you move them further apart, there will be less of the shaft inserted into the bearing. It would be awfully nice to know how much is now engaged. This could be measured by removing the engine and neasuring things up. Assume you're not going to do this .... Can you remember when you brought the engine and box together - in the car or in the garage? You generally struggle to engage the shaft in the spigot bearing then things pop together. Can you remember how far apart the engine and box were at that point? That's how much of the shaft is now engaged in the spigot bearing. We hope that it's significantly more than half an inch. I'm trying to get an idea of whether to go for 1/4 or 1/2 an inch .... if we go a bit too far, there will not be much of the spigot bearing engaged and this will, *in time*, wear the bearing faster than it should. But if we go definitely too far, the shaft will not engage at all in the spigot bearing, allowing the shaft to flop about - and this could well wear out the gearbox input shaft bearing (cos it'll run at an angle, see?). More later ...
3. engine and gearbox mounts ... if we're talking 1/4 inch, I'll assume that the mounts may take up this much error. If there is a bit of clearance at the bolt holes, you can slacken the bolts and tighten then later.
Right, here goes. It's what I'd personally do myself. Read carefully and *please* ask for details, sketches etc.
First, one definition. Bellhousing bolt (bhsg bolt): the big bolts holding the bellhousing to the engine.
1. remove a bhsg bolt. Check how much of it engages into the block. Visualise what it's like when it's 1/4 inch out - do you think there's still enough to hold? I *think* that engaging by equal to the diameter is just enough, 1.5 times is more comfy. I.e. a 1/2 inch diameter bolt should engage by 3/4 inch but by 1/2 in might be OK. If you don't think the bolts are long enough, take your one to a specialist and get a set of longer ones, say 1/2 inch longer. They are probably high tensile ones - a good supplier will know.
2. Get some spacers to fit the bolts. I.e. big *thick* washers. Like, 1 inch diameter, 1.5 inch diameter would be better. If you can find something like that, get plenty - enough to make up say 1/2 inch for every bhsg bolt. Getting the right parts for the job is *more* than half the battle! Take care to get this part right. It'll save time and effort. What's more, if you find yourself using spacers of different thicknesses, this will strain the bellhousing and cause problems or failure.
3. Support the rear of the engine and the front of the gearbox. Slacken (do not remove!!!!) the engine mounts. Slacken all the bhsg bolts by a bit more than 1/4 inch. If you need the longer bolts, remove each bolt in turn and put in a newer bolt leaving it a bit more than 1/4 inch slack. Now you have all the bolts slack.
4. Slide or lever the engine and box apart. Now you have a gap a bit more than 1/4 inch. If you are comfortable that all is safe (it should be while the bhsg bolts are still engaged though slack), get under and look to see if the release bearing is still jammed solid. If it's free, go to 5. If not free, slacken the bhsg bolts a bit more (note: take care they are still well engaged, if not put the longer bolts in instead, one by one). Move the engine and box a bit further and check release bearing clearance again. If you have to move the box more than 1/2 inch to get the release bearing free, then ... : . swear. Go on *really* swear, let rip. Give up for the day as I think you'll have to pull the engine and do a proper fix.
5. Decide how much gap to use. If that 1/4 inch gave plenty of clearance
at the release bearing/gearbox front, go with that. I doubt it if will. If there's just a bit of clearance, give it another 1/8 inch I'd say. If you had to give it more than the 1/4 inch, then go with 1/2 inch. If 1/2 inch didn't give clearance ... covered above.
6. Now make up a spacer of this thickness for every bhsg bolt. Glue them together! You'll see why later. Clamp them together and glue round the edges might work. If you put glue between them, ensure you clamp them up tight - you don't want uneven thicknesses of glue giving different resulting thicknesses - see the point?
7. Put the spacers in position on the bhsg bolts, one by one. Remove a bolt; fiddle a spacer into position; insert the bolt (or a longer bolt if that's what's needed). It'll be easy at the bottom of the bellhousing but harder in other places. Take *great* care not to drop a spacer! (Thats' why you glue them together - only one thing to drop!) Find ways to support them safely eg a strip of masking tape right round the outside of a spacer, peel it off after the bolt is engaged. Masking tape might not work ... try carpet tape? Or hold it by a mole grip if you have a very slender one? Use ingenuity to find a way to hold the thing safely. (In the end I used metal bag ties as they bunched the spacers together but left a 'tail' to hold on to). Put all the spacers in, tighten up the bhsg bolts, tighten the engine mounts. Check you have clearance at the release bearing.
8. Check the clutch lever. There should be a bit of free movement of the lever now.
9. Adjust the clutch cable so there is just a small amount of slack.
10. Check things work! See if the clutch disengages fully - or does it grate when you try to put it in gear?
11. Arrange to cover the gap between engine and box, to stop things falling into the clutch. I'm thinking in terms of 'duct tape', something like that.
That's it. For a proper fix, you should make a spacer of the right thickness to match the bellhsg flange - that way it'll fill the gap, see? You could make it in several bits, no need for it to be all in one. Then this could be fiddled into place with the engine in situ, much as above. You could take cardboard templates with the engine and box slightly apart, see? Fiddle a section of card in the gap, with some of the bolts removed, mark the edge of the bellhsg and the holes. But first I'd do the quicker job with spacers as above, to prove it out.
Above all, keep an eye on the clearance between the release bearing and gearbox over time. It will close up as the clutch plate linings wear down. When it runs out of clearance, it'll wear out the release bearing.
Now this may look like a bloody performance, but I've tried to detail everything even down to some trivial details. It *ought* to work out very much as I've written it, and be a whole lot less work than removing the engine. Don't forget, if you do remove the engine, you still have to check things out, try spacers, prove it out, and make a proper spacer ... or find some other kind of fix. In fact, if you did remove the box, I guess the best solution then would be to put an extra spacer where your adaptor plate goes, between bellhsg and gearbox. If so, ensure you do it right .... is the release bearing fouling actually on the gearbox itself, or on the adaptor plate (in front of the gearbox). If the latter, it should be possible to cut away part of the adaptor plate.
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