These clutch operation problems had become serious. They spoilt the last event and whilst I managed to adjust the mechanism to just avoid totally jamming, it wasn't right.
So the choice back at home was do I carry on making adjustments to get the clutch to work without jamming at all, or do I whip the engine out and get to the bottom of it?
Obvious answer really. Whilst there was another event in 2 weeks time, I wasn't planning on doing it. It was to be at Keighley which, whilst it's 60 miles away , and so is Alston where I'd just been, the trip for my regular passenger Ian would be 100 miles as he lives at Carlisle.
Plus, he would be away for the event anyway, sorting out his boat on the Thames at Chertsey, after all the flooding.
My reticence to take the engine out is to do with the installation which I made so precise that there is no wiggle room. The gearbox is shimmed and bolted to the chassis and the bulkhead has to be removed to get it out so, realistically, the engine has to come out on it's own. As I made the new engine mounts so precisely, getting any movement to fit the spigot shaft into the bush in the flywheel was very difficult.
I had no design slogger.
But a few minutes looking at it brought a light-bulb moment (or as Ian says, a "duh" moment).
All I had to do was remove the cast engine-mount brackets from the cylinder block and I'd have lots of room to joggle things about. Of course it meant having the engine hoist attached first. That meant re-inforcing the steel beam I had put up for it as when I used the hoist to hold up the front of the car when I removed the front coil/dampers the beam twisted.
With that done the engine was out and sitting on the garage floor in an hour or so. I wasn't rushing as I wanted to check various things as I removed them. Like the exhaust header I had made for instance.
I also made use of the better space as I removed bits to play about with the clutch release arm to determine just where it was jamming and what was really releasing it once it had bound-up.
Once the bellhousing was revealed and the clutch release arm and bearing were open to fiddling about with, it became clear that the release bearing housing (which is plastic) was jamming on the spigot shaft sleeve attched to the gearbox. This sleeve is stationary and provide a surface for the release bearing to slide to and away from the clutch cover.
The sleeve had a patch of rust on the top and the bearing was actually sticking on the rust.
If I tilted the bearing slightly it would jam completely. I'm pulling forward with that finger, but it is stuck.
So, to my mind, when it was pulled back from the clutch cover it was free to pivot on the lugs which the release arm uses to pull it backwards and to stop the housing spinning.
When you apply the clutch pedal pressure the release arm bears on the back of the housing to push it forwards, but it is not straight and jams.
This was what I had. I solid clutch pedal at the top of it's travel and not de-clutching at all.
Another thing I wanted to address was that when the release arm was right forwards, as it was when the clutch is fully disengaged, the curve in the contact surface on the arm that is supposed to allow for the change of angle in the arm as it moves was not sufficient to prevent the arm catching the edge of the release bearing housing, which causing it to tilt at that end of the travel.
This was down to a simply error on my part.
Whilst I had inserted a 6mm adaptor plate to join the engine and gearbox, I hadn't thought to pack the release arm pivot pin out to make up for the extra distance to the clutch cover release fingers. So the release arm was having to push further forward to release the clutch.
I couldn't see an obvious reason for the rust to have developed on the spigot shaft sleeve though. It may be that I had been too thorough in cleaning up the parts before assembly. In it's life up until then there had been an oily film over the inside of the bellhousing.
I cleaned up the sleeve and applied a coat of Copperslip grease for the bearing housing to slide on.
I also lengthened the lugs on the release arm which pull the bearing housing back from the clutch. The plastic tabs they pull on are not adjustable and I think that the arm hasn't been pulling the bearing clear of the clutch cover properly. It may be the clutch cover fingers that have actually been throwing the bearing back and that may have been what has been jamming it.
So now that I had addressed everything that I thought could be wrong I put it all back together.
The engine, without the engine-mount brackets, just slid back in in a few seconds and I bolted the brackets back on without any bother.
Adjusting the pedal pushrod again to get the right amount of travel at the right point was a few minutes work and I tested it.
Works beautifully.
At the moment.
Something to keep my eye on though.
This took about a week to complete working now and then and asking advice from a friend.
It was the night I finished that I got the final entry list for the event I wasn't going to do.
I realised I had been a bit previous in deciding not to enter as I could have probably got one of two local friends to passenger for me. Anyway, I thought I may nip across and either help or video some of the action. As it happened I didn't manage to do that as something else took priority.
Maybe I was lucky as the pictures that Glenn took showed it to be cold and windy and the Hills were maybe a bit steep for a first time passenger to feel comfortable with. I noted that Martin , the Clerk of the Course set the tyre pressure to 10 psi for the morning. Quite high and I assume he did that to make it possible to set less steep Hills but still make it difficult to clear them.
They look like they are pretty chilly to me...
Still, it would have been an opportunity to see if my clutch is behaving itself.
I'll find out in April at Hartside.
So the choice back at home was do I carry on making adjustments to get the clutch to work without jamming at all, or do I whip the engine out and get to the bottom of it?
Obvious answer really. Whilst there was another event in 2 weeks time, I wasn't planning on doing it. It was to be at Keighley which, whilst it's 60 miles away , and so is Alston where I'd just been, the trip for my regular passenger Ian would be 100 miles as he lives at Carlisle.
Plus, he would be away for the event anyway, sorting out his boat on the Thames at Chertsey, after all the flooding.
My reticence to take the engine out is to do with the installation which I made so precise that there is no wiggle room. The gearbox is shimmed and bolted to the chassis and the bulkhead has to be removed to get it out so, realistically, the engine has to come out on it's own. As I made the new engine mounts so precisely, getting any movement to fit the spigot shaft into the bush in the flywheel was very difficult.
I had no design slogger.
But a few minutes looking at it brought a light-bulb moment (or as Ian says, a "duh" moment).
All I had to do was remove the cast engine-mount brackets from the cylinder block and I'd have lots of room to joggle things about. Of course it meant having the engine hoist attached first. That meant re-inforcing the steel beam I had put up for it as when I used the hoist to hold up the front of the car when I removed the front coil/dampers the beam twisted.
With that done the engine was out and sitting on the garage floor in an hour or so. I wasn't rushing as I wanted to check various things as I removed them. Like the exhaust header I had made for instance.
I also made use of the better space as I removed bits to play about with the clutch release arm to determine just where it was jamming and what was really releasing it once it had bound-up.
Once the bellhousing was revealed and the clutch release arm and bearing were open to fiddling about with, it became clear that the release bearing housing (which is plastic) was jamming on the spigot shaft sleeve attched to the gearbox. This sleeve is stationary and provide a surface for the release bearing to slide to and away from the clutch cover.
The sleeve had a patch of rust on the top and the bearing was actually sticking on the rust.
If I tilted the bearing slightly it would jam completely. I'm pulling forward with that finger, but it is stuck.
So, to my mind, when it was pulled back from the clutch cover it was free to pivot on the lugs which the release arm uses to pull it backwards and to stop the housing spinning.
When you apply the clutch pedal pressure the release arm bears on the back of the housing to push it forwards, but it is not straight and jams.
This was what I had. I solid clutch pedal at the top of it's travel and not de-clutching at all.
Another thing I wanted to address was that when the release arm was right forwards, as it was when the clutch is fully disengaged, the curve in the contact surface on the arm that is supposed to allow for the change of angle in the arm as it moves was not sufficient to prevent the arm catching the edge of the release bearing housing, which causing it to tilt at that end of the travel.
This was down to a simply error on my part.
Whilst I had inserted a 6mm adaptor plate to join the engine and gearbox, I hadn't thought to pack the release arm pivot pin out to make up for the extra distance to the clutch cover release fingers. So the release arm was having to push further forward to release the clutch.
I couldn't see an obvious reason for the rust to have developed on the spigot shaft sleeve though. It may be that I had been too thorough in cleaning up the parts before assembly. In it's life up until then there had been an oily film over the inside of the bellhousing.
I cleaned up the sleeve and applied a coat of Copperslip grease for the bearing housing to slide on.
I also lengthened the lugs on the release arm which pull the bearing housing back from the clutch. The plastic tabs they pull on are not adjustable and I think that the arm hasn't been pulling the bearing clear of the clutch cover properly. It may be the clutch cover fingers that have actually been throwing the bearing back and that may have been what has been jamming it.
The engine, without the engine-mount brackets, just slid back in in a few seconds and I bolted the brackets back on without any bother.
Adjusting the pedal pushrod again to get the right amount of travel at the right point was a few minutes work and I tested it.
Works beautifully.
At the moment.
Something to keep my eye on though.
This took about a week to complete working now and then and asking advice from a friend.
It was the night I finished that I got the final entry list for the event I wasn't going to do.
I realised I had been a bit previous in deciding not to enter as I could have probably got one of two local friends to passenger for me. Anyway, I thought I may nip across and either help or video some of the action. As it happened I didn't manage to do that as something else took priority.
Maybe I was lucky as the pictures that Glenn took showed it to be cold and windy and the Hills were maybe a bit steep for a first time passenger to feel comfortable with. I noted that Martin , the Clerk of the Course set the tyre pressure to 10 psi for the morning. Quite high and I assume he did that to make it possible to set less steep Hills but still make it difficult to clear them.
They look like they are pretty chilly to me...
Still, it would have been an opportunity to see if my clutch is behaving itself.
I'll find out in April at Hartside.
No comments:
Post a Comment