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Throw out bearing


pgmwgs

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Hi, new member here. Looking for advice on midget 1500 throw out bearing, same as spitfire 1500. Should the bearing be touching the pressure plate at all times, even when foot off pedal. I fitted a new clutch kit about 500 miles ago and now it is a little noisy, if you gently add pressure on pedal it stops. All help appreciated.

 

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Yes the bearing should be in contact as otherwise the pedal would be very floppy at the start of its movement. Sometimes new bearings are quite stiff and, although in contact, dont spin very easily so theres skidding between it and the clutch which stops with a little pressure. Hopefully with a bit of use it will loosen up and start to rotate freely with the pressure plate and the noise will go away.

Note: there is another problem which produces a noise under similar conditions. If the gearbox has a worn layshaft or mainshaft tip needle bearing it can generate a noise even though the gearbox is in neutral but which stops as the clutch is disengaged. This noise, like the previous clutch thrust bearing noise, will probably be drowned out once moving...

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agree  with Jonny   having a budgie in the clucth hsg can be very common  and agree its caused by the diaphragm fingers skidding on the new throwout

if it growls  foot on its a bearing problem  if the tweets stop with a one finger   light press on the pedal its the skidding 

you can add a spring to increase contact or wait and with use the grg frees up and the noise stops 

Pete

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  • 1 month later...
On 16/02/2023 at 16:21, Pete Lewis said:

agree  with Jonny   having a budgie in the clucth hsg can be very common  and agree its caused by the diaphragm fingers skidding on the new throwout

if it growls  foot on its a bearing problem  if the tweets stop with a one finger   light press on the pedal its the skidding 

you can add a spring to increase contact or wait and with use the grg frees up and the noise stops 

Pete

Hi Pete, I have had this since replacing broken clutch lever arm.  Do you have a link / part number for a suitable spring?

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sorry no   its a very diy  supply   even a lenght og bungy cord  would work 

did youre thow out  have wear dimples in the groove ??

and i guess it will be a thin 15mm thick brg  not the 19mm it should be  this all upsets the angle of the arm on the bearing and can pitch it on its sleeve

the solution is move the anti  rotation pin or ding  in the carrier  and add a washer under the spherical pin   these little changes can make a lot of difference 

got some pics if needed 

Pete

 

 

 

 

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10 hours ago, Papa Smurf said:

Hi Pete, I have had this since replacing broken clutch lever arm.  Do you have a link / part number for a suitable spring?

Has it had a nice long run on a hot day to get the bearing up to temperature and its grease runny? Some WD40 squirted in it might have loosened it up so it spins instead of skidding...

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2 hours ago, johny said:

Has it had a nice long run on a hot day to get the bearing up to temperature and its grease runny? Some WD40 squirted in it might have loosened it up so it spins instead of skidding...

Yep, has been like it for a year now. It’s more rattly than budgie noise, so I think it’s more loose than some others. Have been putting off the interior strip down to get to the slave cylinder…

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3 hours ago, Pete Lewis said:

sorry no   its a very diy  supply   even a lenght og bungy cord  would work 

did youre thow out  have wear dimples in the groove ??

and i guess it will be a thin 15mm thick brg  not the 19mm it should be  this all upsets the angle of the arm on the bearing and can pitch it on its sleeve

the solution is move the anti  rotation pin or ding  in the carrier  and add a washer under the spherical pin   these little changes can make a lot of difference 

got some pics if needed 

Pete

 

 

 

 

I am sure you have seen more of these than I have hot dinners but I have posted on here before about this.  see photo of the old throw out lever that suffered a bizarre failure in that the pin connecting the rod from the slave seemed to fail, the end of the con rod then rubbed on the release lever and eventually punched through the back of the release lever (all prior to my ownership).  I replaced release lever with one bought from eBay.  My suspicion is that the geometry of the new release lever is ever so slightly different to the old one (they looked the same to the naked eye) and this is why I have a rattle.

68EF1FE7-75B9-401F-B8CF-DE3167E9F089.jpeg

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Yes  sorry some of what i said was 6cyl    but the pivot point and geometry  of throw out and all the angles they have to move through is often 

very wrong by design   the pins in the throw out groove should follow the centre line of the support tube , any misalignment will try to pitch the brg on its sleeve/tube 

it is common on so many cars as wear takes place that the arc of movement does not follow the centreline 

on the 4 cyl i guess the only way to add some loading is to beef up the spring inside the slave cylinder 

Pete

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7 minutes ago, Pete Lewis said:

Yes  sorry some of what i said was 6cyl    but the pivot point and geometry  of throw out and all the angles they have to move through is often 

very wrong by design   the pins in the throw out groove should follow the centre line of the support tube , any misalignment will try to pitch the brg on its sleeve/tube 

it is common on so many cars as wear takes place that the arc of movement does not follow the centreline 

on the 4 cyl i guess the only way to add some loading is to beef up the spring inside the slave cylinder 

Pete

Anything that fixes it without having to take the gearbox out again is a win in my book!

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It could be rattle from the gearbox itself as I believe the laygear can do this. Do you get the noise when driving as well? If not something you can try is to push lightly on the gear lever from neutral to 4th, clutch engaged with engine on idle but car stationary. You have to be careful it doesnt suddenly go into gear😳 but the idea is the synchro ring starts to transmit torque to the laygear and the noise its making stops....

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5 minutes ago, johny said:

It could be rattle from the gearbox itself as I believe the laygear can do this. Do you get the noise when driving as well? If not something you can try is to push lightly on the gear lever from neutral to 4th, clutch engaged with engine on idle but car stationary. You have to be careful it doesnt suddenly go into gear😳 but the idea is the synchro ring starts to transmit torque to the laygear and the noise its making stops....

I will try but think it is the clutch lever because looking under bonnet I can see the clutch lever pivot pin dancing around in time with the rattle..

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unsympathetic  clatter from gear backlash at idle is very normal Jonny's test is the way to go ,  on some of the gearboxes they added 3 springs to the front layshaft thrust washer 

fitted in holes in the gear case  as a means of adding a bit of drag you will only find them if you remove the clutch hsg.

if the throwout is dancing you may have some diaphragm finger runout making things worse 

Pete 

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  • 5 months later...

Very delayed update (nightmare getting time to work on this…).  Think have finally resolved this issue.  

Pulled gearbox and reassembled lever arm pivot so it has lost its “slop”.  

Also replaced slave push rod and noticed the new one was a few mm longer than the old one.

Final part was to find some 40mm washers on eBay that could be put under the throw out bearing to push the front of bearing out a bit (link for these below).  After much measuring of bearing face relative to bell housing front face and clutch fingers relative to back plate of engine I went with 4 x 1mm thick washers.

The 20 miles or so covered since then seems to have suggested this has worked.  Reasonable clutch action and no rattling clanking or squeaking…

some photos below…

ebay link for washers: https://www.ebay.co.uk/itm/224326415431?var=523117972356

53EC7F0C-3100-428B-A9D4-D565D46BDC65.jpeg

0530C2F6-85CB-4FD4-BDE5-908BC7DCA902.jpeg

3A188033-5F67-4F64-B7AF-83E155D0B543.jpeg

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yes certainly 6cyl brgs are often only 15mm thick not the 19 mm of the originals 

but i dont know if that also happened on 4 cyl brgs. as ive not had to dabble /measure them 

but your fix seems to confirm a thinner brg is around us .

geometry and actuation of clutches is often poorly engineered and less than accurate by design 

triumph were not good at this , one reason many moderns have a concentric slave so everything remains in alignment 

its not easy to do this and would be an expensive option 

im sure there are ones on offer by specialists in taking your wallet 

Pete

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