Roller release/throwout bearing

[mgcjag]

Hi all....just starting up a new thread following a recent failure of a brand new standard carbon type bearing.....so want to start a discussion on Roller type replacements......lets not go down the theory line of how they cant work in our cars as the clutch fork moves in an arc etc.....lets just focus on do they work....have you fitted/used one.....they are very popular in the race scene but they rebuild their engines frequently....so just for road car use....It is a real dilema ftting a new carbon type and not kniwing if it will last a week.....I will also post this on JL for wider coverage......please join in....ask your friends,...... restorers ...please chip in.....thanks...Steve

[1954Etype]

We fitted 2 of these from Denis Welch. We replaced the bushes and fitted new forks and shafts to both cars so knew there was no danger of there being any play in the mechanism.

One of the cars was mine. Both cars had a lot of judder which ended up with us replacing them both with carbon.

If anyone has had success using these, we’d love to know how you did it!

BTW, it’s probably not that much of an issue on a race car as you normally only pull away from rest once.

[Gfhug]

I believe Jeremy's engine was rebuilt by Rob Beere. It certainly is a very smooth sounding and operating engine. I shall PM Jeremy to ask if RB fitted the clutch and if he has any info of which release bearing.

Geoff

[Paul bow]

Hi guys, I’m the one who had the initial problem with the carbon BB release, as previously mentioned it was only 20 mins in on the rolling road, it 100% was set up properly.
I’ve opted for the RB roller bearing obviously because of the issue with the last one, I certainly am not hopping for any clutch judder, this has been an expensive experience. I’ll let you know next week when I get it back.
I’ve raised the issue with SNG, and credit to Julian Barratt who contacted me directly, he is working with me to put this issue to BB, let’s see where we end up.
Must say I’m feeling a tad anxious now after the post above ..

[mgcjag]

Here is a link to the same topic discussion on the JL site....Steve https://forums.jag-lovers.com/t/roller- ... ing/432916

[Paul bow]

Well done steve.. looking forward to hearing others views on this.

[JerryL770]

I discussed this with the engine specialist at the Splined Hub yesterday and his take on it was to not recommend it. I understand the reason for this being that due to the movement of the fork the bearing has to slide across the thrust face on the pressure plate and so therefore is not always concentric with the shaft. Therefore, it is effectively sliding all the time the time the flywheel is rotating with the bearing on the pressure plate. If there is too much friction there, i.e. no lube on the mating faces, shudder will result.

[1954Etype]

Interesting. We put it down to having to remove the ventral ring from the housing fingers. When removed, the fingers weren’t all at the same height.

[Paul bow]

Steve.. if the fingers were misaligned (not same height) I can imagine that would definitely be problematic as the bearing skids and bounces around
I’ve been doing no end of research on this, some for the roller, some against, it’s definitely a problem that you can’t get a reliable carbon bearing, looking on here and JL I’m certainly not on my own with this issue, it has been going on for some time, Borg and Beck has been dealing with this a lot over the years from what I’m reading on these sites.

[angelw]

Hello Jerome,
The max lateral movement from when the Throw Out Bearing contacts the clutch plate is circa 0.799mm, but the full affect depends on how concentric with the centre line it starts at when first contact is made. I think using an annular roller throw out bearing module would be the way to go. The negative, is that if anything hydraulically went wrong with the device, and the gearbox was standard Jaguar, then its an engine and gearbox out to fix it. However, all such devices I've dealt with have been very reliable.

Regards,

Bil

[mgcjag]

There is a bearing here that looks interesting.....roller but with a teflon face.....Australian based seller.....sounds like a good engineering solution...but what do i know.....would be great to hear from anyone thats used one...Steve https://www.ebay.com/itm/HD3306-clutch- ... ect=mobile

[JerryL770]

There is a bearing here that looks interesting.....roller but with a teflon face.....Australian based seller.....sounds like a good engineering solution...but what do i know.....would be great to hear from anyone thats used one...Steve https://www.ebay.com/itm/HD3306-clutch- ... ect=mobile

That seems like a good solution Steve and I should think a lot less than the cost of another engine out job.

Good in that the teflon "non-stick" surface should provide the slippery junction, bearing to pressure plate, to negate any judder.

[Paul bow]

Hi Steve as jerryl above said that looks like a really good alternative..it’s hard to see how that wouldn’t work it’s covering all basis points. .. great bit of research Steve

[mgcjag]

The basic idea sounds good....would need to check that its the correct depth/height....as we know there are different depth bearings available....and find someone thats used one.....Steve

[Paul bow]

…sorry just to add , I’ve messaged the guy and going to have one shipped over from Australia, just to have a spare, it looks on the face of it fantastic bit of engineering, we will see!

[Jeremy]

I believe Jeremy's engine was rebuilt by Rob Beere. It certainly is a very smooth sounding and operating engine. I shall PM Jeremy to ask if RB fitted the clutch and if he has any info of which release bearing.

Geoff

Geoff is correct, RB did mine, lock stock and barrel, i.e. engine clutch and gearbox. For the life of me I can't recall what bearing he used. He and Carl shared so much wisdom when I went to see them I just wish I had been recording, as I can't remember a tenth of it. All I can say is I've had no clutch trouble whatsoever, thankfully. (Not like with the Triumph Dolomite of my youth which was on to its 2nd gearbox and 3rd clutch by 35k miles. I had no hoist so hauled the box out into the inside of the car as per manual....you cannot begin to imagine what a ghastly job that was to do just once, never mind twice....)

[mgcjag]

Hi Jeremy....do you have a car lift...if so you can look into the bellhouseing through the hole in the bottom and see what bearing you have......Steve

[mgcjag]

Hi Paul...note that the ebay bearing being offered is HD3306....as i mention different bearing depths in posts above....the 3306 is the shorter one for the deeper spring clutch cover.....i wasnt suggesting that this bearing was was suitable for all........Steve

[Paul bow]

Yes I am with you Steve, thanks..
I’ll have to take some measurements, he has messaged me back an there is a fly in the ointment in that I have to supply him the old bearing …Australia!