Clutch release
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#1 Clutch release
Hi All,
In the process of installing my new ETF gearbox for my 1969 series 2, the new clutch doesn’t work as the old one did. As per the picture, the release plate of the new clutch is around 1cm lower – towards the front – such that the release bearing doesn’t make contact with the release plate until half way into the travel of the operating fork so it doesn’t disengage. I am talking toUryk about it – any thoughts or experience from you?
Regards, Peter.
http://i1067.photobucket.com/albums/u43 ... clutch.png
In the process of installing my new ETF gearbox for my 1969 series 2, the new clutch doesn’t work as the old one did. As per the picture, the release plate of the new clutch is around 1cm lower – towards the front – such that the release bearing doesn’t make contact with the release plate until half way into the travel of the operating fork so it doesn’t disengage. I am talking toUryk about it – any thoughts or experience from you?
Regards, Peter.
http://i1067.photobucket.com/albums/u43 ... clutch.png
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#2 Re: Clutch release
Hmm..I'm not sure what has been going on here, but the spring clutch you show ( it certainly looks like a spring type) would never have been used on an S2 car ( or indeed on any 4.2) . All 4.2 cars had a diaphragm clutch and the all-synchro box . I am beginning to wonder whether you have a bellhousing for a Moss box which may ( I don't know this for certain ) have a different positioning of the release fork . Mix and match in this area can be a recipe for real trouble, so you need to check that you have the correct flywheel, the correct 4.2 bellhousing, and the correct pre-engaged starter
A start would be to count the number of teeth on the flywheel - there should be 133 . If you have 104 it is a 3.8 flywheel, and if 132 it is from an earlier car such as an XK150
A start would be to count the number of teeth on the flywheel - there should be 133 . If you have 104 it is a 3.8 flywheel, and if 132 it is from an earlier car such as an XK150
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#3 Re: Clutch release
Hi Christopher and All,
Thanks - the flywheel is correct at 4.2 (marked C18517). How can I easily identify the bell housing (3.8 & 4.2; C14494 & C22623) as it is not stamped?
Regards, Peter.
Thanks - the flywheel is correct at 4.2 (marked C18517). How can I easily identify the bell housing (3.8 & 4.2; C14494 & C22623) as it is not stamped?
Regards, Peter.
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#4 Re: Clutch release
Peter
I should try a PM to Peter Crespin or to Angus Moss ( 1954 E type ) . I am not familiar enough with 3.8s to know the differences but Peter in particular may be
Chris
I should try a PM to Peter Crespin or to Angus Moss ( 1954 E type ) . I am not familiar enough with 3.8s to know the differences but Peter in particular may be
Chris
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#5 Re: Clutch release
Flywheel and bell match are not an issue except for starter function. The bearing recess is smaller on 3.8 but many have been machined to fit an all-synchro bearing. If the ETF uses a 4.2 size input bearing then it's either a 4.2 bell or modded 3.8. There were a few 'universal' ones made around the mid sixties when they switched the Mk2 to all-synchro. There are a few other tiny issues but not your problem.Peter Harrison wrote:Hi Christopher and All,
Thanks - the flywheel is correct at 4.2 (marked C18517). How can I easily identify the bell housing (3.8 & 4.2; C14494 & C22623) as it is not stamped?
Regards, Peter.
Chris was quite right in identifying your clutch as the incorrect spring type. It can work (if you don't mind worse grip and heavier action) provided you use the correct offset release bearing, but I'd use a diaphragm every time. As a three-piece kit everything will match and if you were sold that new part for a 4.2 you should get a credit. I assume it wasn't Uryk who suggested a coil spring clutch? That would be like wearing hobnail boots with a DJ.
1E75339 UberLynx D-Type; 1R27190 70 FHC; 1E78478; 2001 Vanden Plas
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#6 Re: Clutch release
Ah, Peter Crespin, I think you've put your finger on the problem . It sounds as though Peter Harrison has a 4.2 type release bearing but the incorrect spring clutch . If changed for a diaphragm, all should be wellPeterCrespin wrote: Chris was quite right in identifying your clutch as the incorrect spring type. It can work (if you don't mind worse grip and heavier action) provided you use the correct offset release bearing,
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#7 Re: Clutch release
Forgive me for being a bit rusty on this topic as it's a while since I've dabbled, but doesn't the flywheel have to be drilled to accept the diaphragm clutch, assuming it's a 3.8 flywheel. i.e. it's not a simple swap. I recall doing it to my own car a few years ago. Forgive me if my memory is playing tricks.christopher storey wrote:Ah, Peter Crespin, I think you've put your finger on the problem . It sounds as though Peter Harrison has a 4.2 type release bearing but the incorrect spring clutch . If changed for a diaphragm, all should be wellPeterCrespin wrote: Chris was quite right in identifying your clutch as the incorrect spring type. It can work (if you don't mind worse grip and heavier action) provided you use the correct offset release bearing,
S1 FHC 3.8, XK Convertible
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#8 Re: Clutch release
Ray, you are correct, although some were "double drilled" to accept either size clutch. Peter Harrison, however, has already confirmed that he has a 4.2 flywheel, so it will accept the proper diaphragm clutch without modification
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#9 Re: Clutch release
Hi All, Peter Harrison again,
Thanks for all your comments. The position appears to be:
1. I definitely have a 4.2 flywheel that can accept either clutch
2. My old clutch (which worked well) was an old spring clutch. Bearing was pretty worn
3. Uryk correctly supplied me with an AP diaphragm 3-piece kit. When assembled, using the supplied bearing, I had the travel problem in the top photo in the first post. So, the bell housing must have been modified to accept the spring clutch & bearing, rendering it unsuitable for Uryk's diaphragm clutch
4. Uryk kindly supplied a second AP spring clutch kit which fitted OK and operates OK wrt travel & release
5. The problem now is flywheel vibration and clutch judder. Is this unlucky or should they be balanced before fitting?
What are my options? Attempt a balance of the new spring clutch/flywheel? Try again with a second spring clutch? Obtain a new bell housing to match the diaphragm kit?
Peter.
Thanks for all your comments. The position appears to be:
1. I definitely have a 4.2 flywheel that can accept either clutch
2. My old clutch (which worked well) was an old spring clutch. Bearing was pretty worn
3. Uryk correctly supplied me with an AP diaphragm 3-piece kit. When assembled, using the supplied bearing, I had the travel problem in the top photo in the first post. So, the bell housing must have been modified to accept the spring clutch & bearing, rendering it unsuitable for Uryk's diaphragm clutch
4. Uryk kindly supplied a second AP spring clutch kit which fitted OK and operates OK wrt travel & release
5. The problem now is flywheel vibration and clutch judder. Is this unlucky or should they be balanced before fitting?
What are my options? Attempt a balance of the new spring clutch/flywheel? Try again with a second spring clutch? Obtain a new bell housing to match the diaphragm kit?
Peter.
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#10 Re: Clutch release
Peter : the clutch cover is invariably balanced in the factory so that rebalancing it is unlikely to achieve much . The flywheel, however, can be badly out of balance and/or out of true, so a check on its balance will probably help, at the very least eliminating one possible cause of your problems
However, what I don't understand is how the effects on travel and release are different with the first and second diaphragm clutches ??
However, what I don't understand is how the effects on travel and release are different with the first and second diaphragm clutches ??
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#11 Re: Clutch release
Hi Christopher,
Thanks - the old clutch was spring, the first replacement was diaphragm (which had the "travel" problem) and the second replacement was a spring (which fitted OK) - leading to my assumption that the bell housing has been modified to accept only spring.
Re vibration/judder I take your point about the flywheel balancing. Just confusing that the balance was fine with the old spring clutch.
Still not sure which way to go forward!
Regards, Peter.
Thanks - the old clutch was spring, the first replacement was diaphragm (which had the "travel" problem) and the second replacement was a spring (which fitted OK) - leading to my assumption that the bell housing has been modified to accept only spring.
Re vibration/judder I take your point about the flywheel balancing. Just confusing that the balance was fine with the old spring clutch.
Still not sure which way to go forward!
Regards, Peter.
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#12 Re: Clutch release
Could be a number of things. Look for oil on the plate, missing (or worn) spigot bearing or misalignment of release bearing onto clutch cober. Worth looking at the oilite bearings in the bell housing where the release bearing pivots (also wear on the release bearing pivot shaft.
Angus 67 FHC 1E33656
61 OTS 875047
61 OTS 875047
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#13 Re: Clutch release
Does the vibration alter when you depress the clutch? And is it consistent regardless of where the driven plate is in relation to the pressure plate? In other words, if you start the engine, release the clutch, engage a gear (to make sure the driven plate has stopped spinning) and then re-engage the clutch so the driven plate ends up in a different position, does it make any difference to the vibration?
The answer might give a clue to where the problem lies. If something has gone wrong with the spigot bearing (although it is hard to see what could go wrong with it) you will likely get a change in the vibration depending on where the driven plate ends up relative to the pressure plate. And again, if this process causes a change in the vibration, it will tell you that the problem lies with the clutch rather than the flywheel.
If the flywheel has been re-drilled, it could in theory be out of true, but then you would need to have had a matching counter-imbalance in the previous clutch to cancel it out, which is stretching credibility a bit!
The answer might give a clue to where the problem lies. If something has gone wrong with the spigot bearing (although it is hard to see what could go wrong with it) you will likely get a change in the vibration depending on where the driven plate ends up relative to the pressure plate. And again, if this process causes a change in the vibration, it will tell you that the problem lies with the clutch rather than the flywheel.
If the flywheel has been re-drilled, it could in theory be out of true, but then you would need to have had a matching counter-imbalance in the previous clutch to cancel it out, which is stretching credibility a bit!
Hugo Miller - rebuilding an imported Series II OTS & converting to RHD
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#14 Re: Clutch release
I'm not clear as to what is depicted in your photo of the bell housing. Is that a second release lever between the original Jaguar lever and the rear of the aperture? If not, and we're talking about the original lever clearance, then it's about the same position as in my car....lever about 60% from the front of the aperture. My diaphragm clutch does release. And if you look at the following current, related thread on Jag-Lovers, the lever will migrate forward as the driven plate wears. Also, I wonder if the throw out bearing in the diaphragm kit was the correct offset (different from the one for coil spring clutch).
https://forums.jag-lovers.com/t/sii-clu ... ent/351510
If the transmission uses a unique release arm and demands a unique clutch (other than OEM), then the supplier should know what it takes to get the job done.
https://forums.jag-lovers.com/t/sii-clu ... ent/351510
If the transmission uses a unique release arm and demands a unique clutch (other than OEM), then the supplier should know what it takes to get the job done.
Eric
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#15 Re: Clutch release
Hi All - Peter H again:
Looks like I have two alternatives:
Re the replacement diaphragm clutch & travel: Eric, thanks for your link to the jag-lovers thread. So, the 60% position of the travel in my photo is quite normal. The concern was that operating the lever with a bar (with the engine out) did not release the clutch even though the fork was at the end of its travel and touching the bell-housing. Maybe the bell-housing needs grinding as per the jag-lovers thread?
Re the judder on the replacement spring clutch: maybe a new flywheel and an attempt at balancing the two before installation is an option.
Any more thoughts welcome!
Regards, Peter.
Looks like I have two alternatives:
Re the replacement diaphragm clutch & travel: Eric, thanks for your link to the jag-lovers thread. So, the 60% position of the travel in my photo is quite normal. The concern was that operating the lever with a bar (with the engine out) did not release the clutch even though the fork was at the end of its travel and touching the bell-housing. Maybe the bell-housing needs grinding as per the jag-lovers thread?
Re the judder on the replacement spring clutch: maybe a new flywheel and an attempt at balancing the two before installation is an option.
Any more thoughts welcome!
Regards, Peter.
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#16 Re: Clutch release
I can't say that the 60% position is normal. All I know is that my diaphragm clutch releases from roughly that location...possibly slightly farther forward, but not by much. And it would seem that others who have been forced to lengthened the adjustable rod are also very likely starting from a relatively rearward position in the opening. That said, if your clutch won't release then you have a different set of circumstances/parts. I'm the poster who mentioned a grinder in the J-l string, and I made that statement under a mistaken understanding regarding how the clutch wears. I expected the carbon bearing to wear (relatively) faster than the clutch disk, thereby requiring the adjustable rod to be extended over time. According the knowledge base who are posting on that string, the opposite is the case, and the threaded rod will have to be shortened over time as the mechanism wears. So if it releases when new, it should be good to go for the long haul (no need to make more space at the aft end of the aperture). IF it releases when new....
Since your clutch won't release within the allotted throw in the aperture, you could grind a little to see if it would release. But it seems something must be amiss in the parts area. The offset of the throw out bearing comes to mind as a possibility. If you had an incorrect "short" TOB installed, it would obviously drive the lever farther toward the rear of the opening. Might also be an issue with the depth of the bearing face on the pressure plate you received. If you want to investigate this, I'd suggest getting with the original poster on that J-L string and share some measurements. That said, I'm not sure if he actually got his clutch to release with the parts he has on hand....
My clutch is a Borg and Beck unit that I purchased way back in the mid-80s, and I don't have any specifics for it (installed and no paper work). I do know that the TOB is the larger offset unit.
Again, I would think the transmission people would have precise information for you. If they thought the diaphragm clutch was the right unit, then they likely sent you incorrect specification parts. Who are these people????
Since your clutch won't release within the allotted throw in the aperture, you could grind a little to see if it would release. But it seems something must be amiss in the parts area. The offset of the throw out bearing comes to mind as a possibility. If you had an incorrect "short" TOB installed, it would obviously drive the lever farther toward the rear of the opening. Might also be an issue with the depth of the bearing face on the pressure plate you received. If you want to investigate this, I'd suggest getting with the original poster on that J-L string and share some measurements. That said, I'm not sure if he actually got his clutch to release with the parts he has on hand....
My clutch is a Borg and Beck unit that I purchased way back in the mid-80s, and I don't have any specifics for it (installed and no paper work). I do know that the TOB is the larger offset unit.
Again, I would think the transmission people would have precise information for you. If they thought the diaphragm clutch was the right unit, then they likely sent you incorrect specification parts. Who are these people????
Eric
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#17 Re: Clutch release
Hi Eric,
Thanks - the new clutch release bearing is definitely the one that came with the Automotive Products 3-piece diaphragm kit so I am guessing that this must be correct. There must be a way to measure the diaphragm release bearing to be sure it is right if compared to the dimensions of the spring release bearing.
My worry is that the people who fitted the spring clutch in 1999 also changed the bell housing and that this changes the position of the fork. How can I be sure without buying a 4.2 bell housing?
The SNG parts guide suggests that for 3.8/4.2 cars, the bell housing/release.bearing/clutch must be matched. The fork remained unchanged 3.8-to-4.2.
The flywheel is 4.2 and doesn't look like it has been skimmed - but I didn't measure or compare it.
Regards, Peter.
Thanks - the new clutch release bearing is definitely the one that came with the Automotive Products 3-piece diaphragm kit so I am guessing that this must be correct. There must be a way to measure the diaphragm release bearing to be sure it is right if compared to the dimensions of the spring release bearing.
My worry is that the people who fitted the spring clutch in 1999 also changed the bell housing and that this changes the position of the fork. How can I be sure without buying a 4.2 bell housing?
The SNG parts guide suggests that for 3.8/4.2 cars, the bell housing/release.bearing/clutch must be matched. The fork remained unchanged 3.8-to-4.2.
The flywheel is 4.2 and doesn't look like it has been skimmed - but I didn't measure or compare it.
Regards, Peter.
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#18 Re: Clutch release
As far as I know, the main dimensional difference between 3.8 and 4.2 bell housings is a very slight shift in the starter location. Hence the matched set admonition ...starter/flywheel/bell housing when I did the retrofit of all synchro transmission for the Moss unit in my '64. There is also apparently a slight clutch clearance difference on the earlier 3.8 bell housing casting (this from my readings on these forums). Anyway, if you have 4.2 flywheel and starter, the odds are very high that it's a 4.2 bell housing. Perhaps some else can verify what I've said.
I wonder if the dimensions of the components in the Automotive Products kit match the original Borg and Beck. Unfortunately my B&B parts are installed. Again, you might want to get in touch with BOFFI (Mark), the original poster on the J-L forum and compare notes.
I wonder if the dimensions of the components in the Automotive Products kit match the original Borg and Beck. Unfortunately my B&B parts are installed. Again, you might want to get in touch with BOFFI (Mark), the original poster on the J-L forum and compare notes.
Eric
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#19 Re: Clutch release
Hi All - me again,
I'll check the release bearing from the AP kit with another one arriving soon from SNG.
Meanwhile, what is the correct thickness of a 4.2 flywheel? I'd like to exclude the possibility that my current flywheel has been overly skimmed, perhaps to accommodate the old spring clutch.
Anybody have a measurement?
Regards, Peter.
I'll check the release bearing from the AP kit with another one arriving soon from SNG.
Meanwhile, what is the correct thickness of a 4.2 flywheel? I'd like to exclude the possibility that my current flywheel has been overly skimmed, perhaps to accommodate the old spring clutch.
Anybody have a measurement?
Regards, Peter.
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#20 Re: Clutch release
I've had the flywheel from engine number 7R 5392 (stamped on the flywheel) since 1985. It came out of a wrecked car. The face is scored and it needs to be resurfaced, but I very much doubt it has ever been machined to this point. The thickness is 1.400 inches.
Eric
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