Engine drop......
Discussion
Well I finally did it.
The car has been in storage for nearly five years, and when I dragged it out a couple of months back the engine started first time, but I couldn't select first gear from a stand. Time for some inspection. Tried a whole pile of cursory things, but to no avail. In addition the rear brakes had seized the CV boots were on their last legs, and the fuel pipes were looking worringly corroded.
The thing is that I was pretty sure that the gearbox is good, because it had always been, and in addition if you jacked the back of the car up, and ran the wheels, you could get all the gears.
With a bit of financial and physical help, (I'll have to buy my ol' man a beer, when I get some cash) changing the clutch and sorting out some of the issues, has become a possibility. Last week was the first phase of operations;
Engine out
Stripping the brakes
Rebuilding the throttle linkage
Clutch, and slave replacement
CV boot replacement
Replacing the fuel and clutch hydraulic lines
I'd never gone quite as grand as dropping the engine before, so I'm sure that rate of progress was somewhat less than perhaps it could have been, had we known what we were doing.
The problem is most likely to be clutch slave. Having removed the engine, and then the slave, it basically just fell into two pieces before being lobbed into the bin. The clutch it's self has never (to my knowledge) been changed. It turns out that it has very little wear to the friction material, flywheel and pressure plate at all. The release bearing was a bit sloppy for sideplay, but still in satisfactory condition.
The clutch it's self was an absolute pig to change. Had things gone according to what appears to be the factory plan, it should have been a piece of cake. The clutch is of the pull type. That is to say that the release fork pulls the clutch spring away from the flywheel in order to release the clutch.
The implication is that the normal method for separating the engine and gearbox is to remove the pivot pin, for the clutch fork, from the side of the gearbox such that the fork can be disengaged from the release bearing. Obviously the release bearing is attached to the engine, through the pressure plate.
Unfortunately the clutch fork and pivot pin corrode into a single item, and because the fork is captive between the supports for the pivot pin, it cannot be slid out, even using the threaded hole in the end of the pivot, and a substantial puller.
In the end all you can do is to remove the bolts for the pressure plate through the hole for the starter motor, and remove the gearbox from the engine, with the pressureplate still inside the gearbox. Luverly!
Then somehow you have to get the clutch out of the bellhousing from the wrong side. The release bearing, is held into the clutch spring by a wire in a slot on the flywheel side, which you can get at. Unfortunately it's captive behind a washer that pulls the clutch spring in normal operation. The washer and the retaining wire are held in place by a spring washer, which is on the other side clutch spring. Nice.....
The solution is to use a hacksaw to cut the retaining spring, by putting it through the gaps in the clutch spring, to gain access to the other side of the clutch. That allows the pull washer to be pushed back, and one can then prise the retaining wire out. The pressure plate can then be drawn out of the bell housing.
Then to the clutch fork. By this time you can see the fork directly, and realise that it's seized onto the pivot pin, and that's why you couldn't dismantle clutch normally. In the end the only way to remove the fork, is to grind slots into the fork. Fortunately it's cast iron, and you can use the slots you grind to create weak points that cause it to shatter when tickled with a cold chisel. Precision engineering at it's best.
Once the clutch fork is gone, you can pull the pivot out, from the side of the gearbox normally.
I don't know why, but porsche in their wisdom decided to use needle roller bearings for the pivot pin. The damn thing barely rotates ten degrees, but hey, that's German engineering for you. The bearing shells are pressed into "ears" inside the bell housing. The outer shell pulls out with the pin, but the inner shell is in a blind hole to which there is no significant access. The inner shell is like a cup inside the ear. It has no holes, so you can't hydraulic it out. You have two choices. The first it to use a special tool that Porsche no longer sell to cut the shell out. The alternative is to drill a hole through the bellhousing, using a long series drill, and follow through into the back of the ear. Then you can use a rod/punch to tap the thing out, from outside the bell housing.
Fortunately, re-assembly is not the reverse of removal!!
Anyway, all was well, and so far it's been a sucess, but who knows whats around the corner. Re-assembly of engine into car, is early January. More pics will follow. Apologies for the quality of my pics, I never was much of a cameraman.
The car has been in storage for nearly five years, and when I dragged it out a couple of months back the engine started first time, but I couldn't select first gear from a stand. Time for some inspection. Tried a whole pile of cursory things, but to no avail. In addition the rear brakes had seized the CV boots were on their last legs, and the fuel pipes were looking worringly corroded.
The thing is that I was pretty sure that the gearbox is good, because it had always been, and in addition if you jacked the back of the car up, and ran the wheels, you could get all the gears.
With a bit of financial and physical help, (I'll have to buy my ol' man a beer, when I get some cash) changing the clutch and sorting out some of the issues, has become a possibility. Last week was the first phase of operations;
Engine out
Stripping the brakes
Rebuilding the throttle linkage
Clutch, and slave replacement
CV boot replacement
Replacing the fuel and clutch hydraulic lines
I'd never gone quite as grand as dropping the engine before, so I'm sure that rate of progress was somewhat less than perhaps it could have been, had we known what we were doing.
The problem is most likely to be clutch slave. Having removed the engine, and then the slave, it basically just fell into two pieces before being lobbed into the bin. The clutch it's self has never (to my knowledge) been changed. It turns out that it has very little wear to the friction material, flywheel and pressure plate at all. The release bearing was a bit sloppy for sideplay, but still in satisfactory condition.
The clutch it's self was an absolute pig to change. Had things gone according to what appears to be the factory plan, it should have been a piece of cake. The clutch is of the pull type. That is to say that the release fork pulls the clutch spring away from the flywheel in order to release the clutch.
The implication is that the normal method for separating the engine and gearbox is to remove the pivot pin, for the clutch fork, from the side of the gearbox such that the fork can be disengaged from the release bearing. Obviously the release bearing is attached to the engine, through the pressure plate.
Unfortunately the clutch fork and pivot pin corrode into a single item, and because the fork is captive between the supports for the pivot pin, it cannot be slid out, even using the threaded hole in the end of the pivot, and a substantial puller.
In the end all you can do is to remove the bolts for the pressure plate through the hole for the starter motor, and remove the gearbox from the engine, with the pressureplate still inside the gearbox. Luverly!
Then somehow you have to get the clutch out of the bellhousing from the wrong side. The release bearing, is held into the clutch spring by a wire in a slot on the flywheel side, which you can get at. Unfortunately it's captive behind a washer that pulls the clutch spring in normal operation. The washer and the retaining wire are held in place by a spring washer, which is on the other side clutch spring. Nice.....
The solution is to use a hacksaw to cut the retaining spring, by putting it through the gaps in the clutch spring, to gain access to the other side of the clutch. That allows the pull washer to be pushed back, and one can then prise the retaining wire out. The pressure plate can then be drawn out of the bell housing.
Then to the clutch fork. By this time you can see the fork directly, and realise that it's seized onto the pivot pin, and that's why you couldn't dismantle clutch normally. In the end the only way to remove the fork, is to grind slots into the fork. Fortunately it's cast iron, and you can use the slots you grind to create weak points that cause it to shatter when tickled with a cold chisel. Precision engineering at it's best.
Once the clutch fork is gone, you can pull the pivot out, from the side of the gearbox normally.
I don't know why, but porsche in their wisdom decided to use needle roller bearings for the pivot pin. The damn thing barely rotates ten degrees, but hey, that's German engineering for you. The bearing shells are pressed into "ears" inside the bell housing. The outer shell pulls out with the pin, but the inner shell is in a blind hole to which there is no significant access. The inner shell is like a cup inside the ear. It has no holes, so you can't hydraulic it out. You have two choices. The first it to use a special tool that Porsche no longer sell to cut the shell out. The alternative is to drill a hole through the bellhousing, using a long series drill, and follow through into the back of the ear. Then you can use a rod/punch to tap the thing out, from outside the bell housing.
Fortunately, re-assembly is not the reverse of removal!!
Anyway, all was well, and so far it's been a sucess, but who knows whats around the corner. Re-assembly of engine into car, is early January. More pics will follow. Apologies for the quality of my pics, I never was much of a cameraman.
Edited by dilbert on Thursday 7th December 12:10
..................................................................... 
Now I know why the cost of my clutch renewal, was set to spiral
a couple of years back.
He complained and bitched about over tightened bolts,
sadly he'd not allowed this in his written quote, so I guess he earned his money.
Looks a very involved job and like mine, as still sporting the showroom plate at the end of it.
Metering head fitted on Thursday,
15 starts later no smoke they said,
all being well its coming back on Tuesday,
a couple of years back.
He complained and bitched about over tightened bolts,
sadly he'd not allowed this in his written quote, so I guess he earned his money.
Looks a very involved job and like mine, as still sporting the showroom plate at the end of it.
Metering head fitted on Thursday,
15 starts later no smoke they said,
all being well its coming back on Tuesday,
With this, the biggest problem was the rust effect. It's amazing how the exposed parts like fixings go rusty, even though they are plated when new.
Fortunately we were aware that many of the fixings were a bit iffy, so most of the nuts, bolts, washers, and studs have been replaced and put back together with copper grease. If you know you have replacement fixings, it doesn't matter if you need to cut the old ones out. Hopefully it'll make it easier if there's a next time, anyway.
Certainly, there are many jobs that are difficult without taking the engine out, and there is much that I would like to do, that time and money does not allow. It doesn't make much difference, but I'd like to replace the metal shroud around the engine, but that will have to come with the top end rebuild.
The main thing from my point of view is to get at all the stuff around the gearbox sorted. Theres a bit of a void in there, behind the floorpan, and I think the road smeg lifts into that space when the car is moving at any speed. The problem comes from the fact that all of the controls and ancilliaries come through the rear bulkhead at that point. Getting all that stuff renewed is worth it's weight, in terms of reliability and future ease of working.
A new exhaust would be nice too, but given that there's nothing actually wrong with the old one, I guess I'm glad I don't have to shell out for one!!
Fortunately we were aware that many of the fixings were a bit iffy, so most of the nuts, bolts, washers, and studs have been replaced and put back together with copper grease. If you know you have replacement fixings, it doesn't matter if you need to cut the old ones out. Hopefully it'll make it easier if there's a next time, anyway.
Certainly, there are many jobs that are difficult without taking the engine out, and there is much that I would like to do, that time and money does not allow. It doesn't make much difference, but I'd like to replace the metal shroud around the engine, but that will have to come with the top end rebuild.
The main thing from my point of view is to get at all the stuff around the gearbox sorted. Theres a bit of a void in there, behind the floorpan, and I think the road smeg lifts into that space when the car is moving at any speed. The problem comes from the fact that all of the controls and ancilliaries come through the rear bulkhead at that point. Getting all that stuff renewed is worth it's weight, in terms of reliability and future ease of working.
A new exhaust would be nice too, but given that there's nothing actually wrong with the old one, I guess I'm glad I don't have to shell out for one!!
Edited by dilbert on Saturday 9th December 20:07
My existing system is all Porsche and mild steel. The heat exchangers themselves were replaced just prior to me buying the car some eight years ago. I've only put 15,000 miles on it in that time, so they havn't really suffered.
The thing that did surprise me is the flapper boxes (as Henry calls them). The car is one of the first of the 3.2 Carreras, and although it has that build standard, it also has the earlier boxes. The boxes themselves look O.K., but the clips and things are in really bad shape, so the plan is to strip them, clean them up and paint them, with all new clips and hoses.
The other thing I noticed is that although it has the later ECU it has no oxygen sensor. I think this might be because it was made before the requirement for an exhaust catalyst.
The thing that did surprise me is the flapper boxes (as Henry calls them). The car is one of the first of the 3.2 Carreras, and although it has that build standard, it also has the earlier boxes. The boxes themselves look O.K., but the clips and things are in really bad shape, so the plan is to strip them, clean them up and paint them, with all new clips and hoses.
The other thing I noticed is that although it has the later ECU it has no oxygen sensor. I think this might be because it was made before the requirement for an exhaust catalyst.
Edited by dilbert on Saturday 9th December 20:18
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