Trouble Engaging Gear

[edworcs]

Having real problems getting into gear and I'm stuck for ideas. Would appreciate some tips on what to look for next:

1969 Amazon
Cable Clutch
Gearbox with Overdrive (I _think_ D Type on an M40 box? - too dark to look now)

I retrofitted a supposedly "known good" overdrive gearbox to my Amazon. The clutch was inspected as was found to be good (including release bearing). I needed a new clutch cable which I fitted (last one burnt in a stupid fire accident). I filled up the gearbox with fresh oil having previously drained it (Gear oil and not 20/50). I have left the wiring for the overdrive deliberately disconnected and still don't know if it works. I figured that I'd be better off trying to get the gearbox to work first.

The clutch cable is at its maximum adjustment (tightest, no more thread left) and the clutch pedal is pushed down very hard (much harder than my old non overdrive box and requires some force) and I can just about find and select gear. Slackening the clutch cable makes engaging a gear impossible. Reverse really crunches. Driving is uncomfortable to say the least owing to the 15 second gear changes :-)

My hunch is clutch, but I can't see what could be wrong. I've even printed out the clutch pedal diagram from the Green Book and compared it to my pedal thinking that I had managed to muck that up, but it looks OK.

What should I be looking for? Any tips most gratefully received.

Ed

[Peter Keen]

I had the same problem in reverse with my Amazon it was slipping, despite a new driven and pressure plate, I would suggest you check the width of the release bearing. Talk to Simon @ Brookhouse he`ll put you right.

[Dylan144GT]

Hi

I suspect it is your clutch fork. The symptoms are identical to a situation I had. Fully adjusted cable and serious pressing of the pedal made no difference and the gears were impossible to engage. The clutch forks for the early cars are notoriously weak. They tend to crack very close to the bearing and bend. When it happened to me I had to remove the gearbox, bend it back into shape, seam weld the fracture on either side and then welded in a backing support to ensure it didn't happen again. Remove the rubber clutch fork boot and peer into the bell housing with a torch. The cracks should be visible if they are the culprits!

If you are unable to weld it source one from a later 140. These were factory reinforced as the problem was already occurring back then!

Hope this helps

Dylan

[edworcs]

Thanks for the help.

The bearing and fork were taken from the previous gear box / clutch assembly where they were working beautifully. I looked over the bearing before fitting as well as the fork. The fork seemed to be in good shape, but I didn't inspect it carefully for cracks.

A little more info might be useful here.

First time the gearbox was fitted I used a less than good clutch together with release bearing and fork from the overdrive gearbox. I had the exact same problem (difficulty engaging gear) which led me to take the gearbox out and replace the clutch with my known good one (and which was inspected carefully). I also changed the fork and bearing at the same time to the ones from my old non overdrive box.

So, symptoms are the same with two different clutches, bearings and release forks.

[Derek UK]

Even after reading this through a couple of times I'm still not sure the right combination of parts are being used. There are two styles of clutch, one by F&S (Fichtel & Sachs) and one by Borg & Beck. The 2 types are interchangeable but only when matched to their own release bearing. If the 2 clutches are laid flat on the bench they have different heights. This difference is made up by the the matching release bearings. None of the 3 parts of each clutch is interchangeable. If you don't know this it's easy to buy a clutch and put it in and find that you get the problem you have now because it doesn't match the one you're replacing. i.e. you might have a F&S clutch with a B&B release bearing. Sorry, that won't work and neither will the opposite combination.
You may be convinced that yours is correct but you'll be taking it out again I expect so you can properly compare the two. Hopefully it will just mean swapping release bearings. Short bearing on tall clutch cover and vice versa sounds reasonable
From the parts books - B18 cars were fitted with either of the 2 clutches but the B20 came originally with the F&S one. (B&B will fit B20 with a matching release bearing) B&B bearing is 43mm deep and F&S one is 36.5mm. Just to confuse you, there is a 32mm one which came with B&B cltches on very early B18 cars but you're unlikely to have one of those unless someones found one at the back of a dusty shelf.
As mentioned, check your pressed steel arm for cracks. Frustrating it may be but I hope it goes together OK this time. Consider getting the OD wiring to the GB cover switch sorted while fitting the box as it's not easy to do it when the GB is in the car.

[edworcs]

Thanks to all for the help so far ... I think I'm just postponing the inevitable task of having to remove the gearbox once again :-( but to clarify my thoughts and witterings I put together an overview of events:

http://www.worcs.co.uk/volvo_clutch/

The combination that is currently in the car came out of the same car when it had a non overdrive gearbox (Combination 2 on the web page above).

Does an overdrive gearbox require a different type of clutch? I've gone from a B20A to a B20B engine during the process. Is there any difference there that could be the problem (thinner flywheel etc.)? Could anything else be causing this? <sigh>Better get my overalls. I need to make the National!