Relationship between Clutch and Crankshaft
Discussion
I've pressed them today to give me a detailed explanation of the failure mode, ie, how did end float effect the clutch pedal, and they have finally acquiesced and will get Ford Technical to give me a write up that I can scrutinise so hopefully I can return with something interesting later on.
Slightly troubling is that the garage tech said that they have no idea if the short block change out will even fix the clutch pedal problem... I'm pulling my hair out here. Its mental that no one has questioned this on their end.
Slightly troubling is that the garage tech said that they have no idea if the short block change out will even fix the clutch pedal problem... I'm pulling my hair out here. Its mental that no one has questioned this on their end.
Wrathalanche said:
I've pressed them today to give me a detailed explanation of the failure mode, ie, how did end float effect the clutch pedal, and they have finally acquiesced and will get Ford Technical to give me a write up that I can scrutinise so hopefully I can return with something interesting later on.
Slightly troubling is that the garage tech said that they have no idea if the short block change out will even fix the clutch pedal problem... I'm pulling my hair out here. Its mental that no one has questioned this on their end.
Let them do the short block, No point in investigating the clutch further until then. Slightly troubling is that the garage tech said that they have no idea if the short block change out will even fix the clutch pedal problem... I'm pulling my hair out here. Its mental that no one has questioned this on their end.
If it's worn it maybe prudent to pay for a new pressure plate or whatever while it's all apart.
Mr2Mike said:
It would be crazy not to fit a new clutch at this point if it really is 75% worn.
I totally agree, but I absolutely don't want to pay £400 for a new clutch on a 2 year old car if I don't need to, because if it turns out it has suffered as a result of the end float condition, it should be part of the warranty repair in my opinion. I'm perfectly happy for them to the do the short block, in fact I was expecting the car back about 3 weeks ago with the new block, but got the call about the clutch when they were about to rebuild it and I told them to stop the job so it could be investigated properly.
Folks - just a thought - are the big-end and main journals able to take a 1.2 mm longitudinal movement of the crank shaft? If lateral force is applied to the conrods, it will cause unnecessary wear on the big-end journals. I'm surprised that even the main bearings are long enough to allow that. 1.2 mm seems like a lot.
Does this engine have end-float shells on the crankshaft? Are they both there?
Does this engine have end-float shells on the crankshaft? Are they both there?
1.4 mm sounds like a lot of end float. However, I'm surprised that stops the clutch coming up and engaging. I wonder if there's a mechanical problem in the clutch that stops it engaging and that mechanical problem has caused a load on the thrust bearing and accelerated wear. With that sort of wear, it's likely that a lot of metal particles have circulated around the engine and damaged other bearings ...
Peter3442 said:
1.4 mm sounds like a lot of end float. However, I'm surprised that stops the clutch coming up and engaging. I wonder if there's a mechanical problem in the clutch that stops it engaging and that mechanical problem has caused a load on the thrust bearing and accelerated wear. With that sort of wear, it's likely that a lot of metal particles have circulated around the engine and damaged other bearings ...
Yes that seems logical for the failure described, probably a little to much for a Ford tech to comprehend. Peter3442 said:
1.4 mm sounds like a lot of end float. However, I'm surprised that stops the clutch coming up and engaging. I wonder if there's a mechanical problem in the clutch that stops it engaging and that mechanical problem has caused a load on the thrust bearing and accelerated wear. With that sort of wear, it's likely that a lot of metal particles have circulated around the engine and damaged other bearings ...
That would have been felt through the pedal though, either greatly stiffening up or comming to a dead stop before the pedal reached the bottom of its stroke."That would have been felt through the pedal though"
I'd agree with you, but can't think of a better explanation of the symptoms. The pedal might be stiffer on the down stroke, but not enough to be noticeable.
OP said the clutch is sometimes not coming back up. I am not familiar with the car, but for sure there's one or more return springs that could be malfunctioning. There could be something making the slave or master cylinder stiff on the return stroke. There could be 'something' that can jam in the mechanism when the pedal is closest to the floor. Or a mixture of all those.
I'd agree with you, but can't think of a better explanation of the symptoms. The pedal might be stiffer on the down stroke, but not enough to be noticeable.
OP said the clutch is sometimes not coming back up. I am not familiar with the car, but for sure there's one or more return springs that could be malfunctioning. There could be something making the slave or master cylinder stiff on the return stroke. There could be 'something' that can jam in the mechanism when the pedal is closest to the floor. Or a mixture of all those.
AW111 said:
When they say "a short block", is that just the block, or does it include crank & pistons etc.?
As I understand it, just the block.So the latest is that Ford Technical have come back saying that they can't actually give a definitive reason for why the clutch pedal sticking on right handers would be caused by an engine with excessive end float. It actually might not solve the pedal issue, but their experience has shown that in the past, on Fiesta STs, sorting the end float issue made the pedal problem go away on any car that had both symptoms. This is immensely frustrating as an engineer myself, as I'm constantly reporting on failure modes and defects on submersible mechanical and hydraulic systems, and such a vague reply would never be accepted by the technical authorities of our clients.
With regards to the condition of the clutch disc, they have stated that if there was no slippage (and there never has been), then they can conclude that the clutch itself has been operating correctly and that this end float issue/pedal problem has not had any effect on the wear of the clutch. So I'm out of arguments for now, and shelling out for a new one while the engine is in bits at the moment.
Wrathalanche said:
AW111 said:
When they say "a short block", is that just the block, or does it include crank & pistons etc.?
As I understand it, just the block.Mr2Mike said:
Wrathalanche said:
AW111 said:
When they say "a short block", is that just the block, or does it include crank & pistons etc.?
As I understand it, just the block.Also, I would expect the manufacturer would much rather ship a factory-assembled short motor than trust a dealership's engine building skills.
Peter3442 said:
... factory assembled is probably also much cheaper than leaving it to a (competent) dealer. I wonder if it might not be cheaper still to send an engine complete with cylinder head?
They often do, some manufacturers (quite wisely) won't let the spanner monkeys inside. If an engine develops a serious fault then the whole unit is dropped out and sent back to HQ for examination. It makes sense if you think about it, then they can then do a proper PM on it to find the cause and build better engines, instruct a recall if needed etc.This all sounds a bit fishy to be honest & some of it just doesn't make very much sense.
Between clutch cover spring wear, wear at the tips of the cover fingers where the release bearing contacts, wear on the face of the release bearing & wear of it's internal bearings I imagine it's all well in excess of the quoted end float issue. I've seen a good few release bearings that have been replaced due to excessive noise, which on removal have been found to be near demolished & absolutely exceeding any amount of survivable crank end float.
Are the Master Techs from the repairing branch, seconded from a larger dealership or is it dealer speak for Ford Technical over the phone?
A few possible alternative scenarios;
Fault has been found with the clutch actuation, the box has been dropped & the worn clutch noticed. Clutches don't usually fly under warranty & may involve a call from the tech to Ford warranty &/or technical. If there is a know issue with end float on the specific engine code / engine build on your vehicle the tech may have been asked to measure float when the box was off, the numbers say it's a duffer & a short block (complete engine, crank, pistons & so on, but less head & ancillaries) replacement instructed. In this scenario the clutch issue & float are unconnected, but now that you know it's a considerably larger job (which you think is connected), you will accept the additional time incurred for the completion of the repair.
The tech has for some reason measured float while the box was off, found it exceeding limits, contacted Ford technical & been authorised to replace it, the clutch & float issues remain unconnected. There are various reasons why this may occur.
The chance of getting a clutch on warranty are pretty if not exceptionally slim unless there is an obvious defect - it may be 75% worn, it may not...... Considering that the labour involved in a clutch change will likely exceed the cost of the clutch itself I would advise getting the dealer to do the job & request some consideration for goodwill on the price of the clutch. Doing this would also save your car from having open heart surgery a second time round.
My money is on a master or slave cylinder being the cause of the pedal failing to return.
Between clutch cover spring wear, wear at the tips of the cover fingers where the release bearing contacts, wear on the face of the release bearing & wear of it's internal bearings I imagine it's all well in excess of the quoted end float issue. I've seen a good few release bearings that have been replaced due to excessive noise, which on removal have been found to be near demolished & absolutely exceeding any amount of survivable crank end float.
Are the Master Techs from the repairing branch, seconded from a larger dealership or is it dealer speak for Ford Technical over the phone?
A few possible alternative scenarios;
Fault has been found with the clutch actuation, the box has been dropped & the worn clutch noticed. Clutches don't usually fly under warranty & may involve a call from the tech to Ford warranty &/or technical. If there is a know issue with end float on the specific engine code / engine build on your vehicle the tech may have been asked to measure float when the box was off, the numbers say it's a duffer & a short block (complete engine, crank, pistons & so on, but less head & ancillaries) replacement instructed. In this scenario the clutch issue & float are unconnected, but now that you know it's a considerably larger job (which you think is connected), you will accept the additional time incurred for the completion of the repair.
The tech has for some reason measured float while the box was off, found it exceeding limits, contacted Ford technical & been authorised to replace it, the clutch & float issues remain unconnected. There are various reasons why this may occur.
The chance of getting a clutch on warranty are pretty if not exceptionally slim unless there is an obvious defect - it may be 75% worn, it may not...... Considering that the labour involved in a clutch change will likely exceed the cost of the clutch itself I would advise getting the dealer to do the job & request some consideration for goodwill on the price of the clutch. Doing this would also save your car from having open heart surgery a second time round.
My money is on a master or slave cylinder being the cause of the pedal failing to return.
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