mazfg Posted May 25, 2017 Share Posted May 25, 2017 Whilst on the drive, engine running, if I push hard down on the clutch I get a rumbling sound. It stops if I let up the pedal slightly? Doesn't do it every time but wondering what this might be? Only seems to happen with a hard push towards the end of travel?If the clutch is engaged I do have a different rumble sound which I guess is the release bearing. It's a NOS part as was the clutch when it went in. Quote Link to comment Share on other sites More sharing options...
garyf Posted May 25, 2017 Share Posted May 25, 2017 Worn Thrust Washers maybe? Quote Link to comment Share on other sites More sharing options...
Spider Posted May 26, 2017 Share Posted May 26, 2017 Quoted from garyf Worn Thrust Washers maybe? +1 Best to check crank endfloat, eliminate that as a source of the noise first, otherwise it will be gearbox out and in again only to find the noise still present 🙁 Also if you have excessive endfloat it is better to get it sorted sooner rather than later as it can ruin the crank and at worst the block as well. Quote Link to comment Share on other sites More sharing options...
glang Posted May 26, 2017 Share Posted May 26, 2017 If you get a noise with the pedal released and gearbox in neutral it'll be gearbox bearings. Its very common and could be either/both the needle roller bearings of the input/main shaft or layshaft. Gearbox oil level is important and they can last quite a while if treated gently but could eventually fail badlly..... Quote Link to comment Share on other sites More sharing options...
mazfg Posted May 26, 2017 Author Share Posted May 26, 2017 Quoted from glang If you get a noise with the pedal released and gearbox in neutral it'll be gearbox bearings. Its very common and could be either/both the needle roller bearings of the input/main shaft or layshaft. Gearbox oil level is important and they can last quite a while if treated gently but could eventually fail badlly..... I've just had the main bearings changed on the gearbox..but wasn't too happy as I think the needle bearings for the layshaft weren't?? Quote Link to comment Share on other sites More sharing options...
glang Posted May 26, 2017 Share Posted May 26, 2017 Depending on who did the work I think you have a claim as usually changing the layshaft spindle and its needle rollers plus the input shaft caged bearing is the first thing to do. Those bits are always included in gearbox overhaul kits. Quote Link to comment Share on other sites More sharing options...
mazfg Posted May 26, 2017 Author Share Posted May 26, 2017 Quoted from glang Depending on who did the work I think you have a claim as usually changing the layshaft spindle and its needle rollers plus the input shaft caged bearing is the first thing to do. Those bits are always included in gearbox overhaul kits. Don't think he got an overhaul kit..just bearings 🤔 . Quote Link to comment Share on other sites More sharing options...
glang Posted May 26, 2017 Share Posted May 26, 2017 Ive put some gloop in mine (non overdrive) to try n make it last a bit longer but it'll have to come out at some stage and I just hope neither the layshaft gear nor the mainshaft bearing surfaces will have been damaged.... Quote Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 26, 2017 Share Posted May 26, 2017 simple test , if you press the pedal with it in a gear when stationary and theres a noise its throwout or thrusts as the gearbox and clutch disc will not be rotatingif you sit with it idling and you press firmly to engage a gear without declutching the syncro should baulk the change but the drag applied will quieten any backlash clatter ..... any gearbox will go quieter if you try this its normal , its the racket set up by all the gears having backlash , some triumph boxes had the 3 springs on the front lay thrust washer to absorb some of this clatter.Pete Quote Link to comment Share on other sites More sharing options...
glang Posted May 26, 2017 Share Posted May 26, 2017 Ok I'll try that second test with fingers crossed Gearbox has done 67k from new Quote Link to comment Share on other sites More sharing options...
daver clasper Posted May 26, 2017 Share Posted May 26, 2017 Not sure about mainshaft bearing surface, but Mike Papworth re did my layshaft gear bearing surface.I think it was a remanufactured/new layshaft that caused the problem as G/B had not done that many miles since a previous rebuild. It was rebuilt with a good, used layshaft.Dave Quote Link to comment Share on other sites More sharing options...
mazfg Posted May 31, 2017 Author Share Posted May 31, 2017 Checked for endfloat and it's rock solid when clutch depressed. Quote Link to comment Share on other sites More sharing options...
Spider Posted May 31, 2017 Share Posted May 31, 2017 Quoted from mazfg Checked for endfloat and it's rock solid when clutch depressed. It will be as the clutch is pushing the crank forwards. Now release the clutch and push the crank back towards the gearbox and measure how much it moves. A dial gauge is best for measuring, I use the front pulley as a reference and a pry bar behind pulley to move crank forwards and backwards. Feeler gauges can be used behind the pulley to measure the endfloat (on a GT6 in my case), can also be done by an experienced eye. I suspect that from your symptoms that the end float is probably okay, but best to check your working from a solid base to start with, and if it was excessive best repaired sooner than later. Quote Link to comment Share on other sites More sharing options...
glang Posted May 31, 2017 Share Posted May 31, 2017 Not sure what you mean about 'rock solid when clutch depressed'. I would check endfloat of the crank without touching the clutch and just pull the crank fanbelt pulley back n forwards. You might have to do it with the engine hot as then it should move more freely or use some sort of lever to get it to move then it should give you an idea of the play. It should be minimal but if you want a number you'll probably need a dial gauge...... Quote Link to comment Share on other sites More sharing options...
Dogsbody47uk Posted June 1, 2017 Share Posted June 1, 2017 Quoted from glang Not sure what you mean about 'rock solid when clutch depressed'. I would check endfloat of the crank without touching the clutch and just pull the crank fanbelt pulley back n forwards. You might have to do it with the engine hot as then it should move more freely or use some sort of lever to get it to move then it should give you an idea of the play. It should be minimal but if you want a number you'll probably need a dial gauge...... I believe the tolerance is 6 to 14 thou. My Vitesse was 18 thou. New standard size thrust washers solved that. Quote Link to comment Share on other sites More sharing options...
mazfg Posted December 19, 2017 Author Share Posted December 19, 2017 Well having removed my clutch I think I've found the rumbling cause... As I said that when I push right down I get a noise of something catching...seems it's the friction plate springs..judging by the marks as can be seen. I guess that extra travel causes it to stick and rub?Last thing I changed was my slave cylinder..before the gearbox went back in....maybe too much travel now....https://ibb.co/iUkSvR Quote Link to comment Share on other sites More sharing options...
glang Posted December 19, 2017 Share Posted December 19, 2017 Its strange that the rub marks on the springs in the pic are on the flywheel side of the friction plate as if theyve been rubbing on the flywheel and I wouldnt expect that to happen with the pedal depressed if fact just the opposite..... Quote Link to comment Share on other sites More sharing options...
mazfg Posted December 19, 2017 Author Share Posted December 19, 2017 Quoted from glang Its strange that the rub marks on the springs in the pic are on the flywheel side of the friction plate as if theyve been rubbing on the flywheel and I wouldnt expect that to happen with the pedal depressed if fact just the opposite..... Maybe the extra travel causes it to push and catch on the 4 bolts that hold the flywheel in??What happens if it's put in the wrong way round out of interest? Quote Link to comment Share on other sites More sharing options...
glang Posted December 19, 2017 Share Posted December 19, 2017 But when you press the pedal it releases the force on the friction plate so if anything it should move away from the flywheel. It was in the right way round wasnt it? Quote Link to comment Share on other sites More sharing options...
mazfg Posted December 19, 2017 Author Share Posted December 19, 2017 Quoted from glang But when you press the pedal it releases the force on the friction plate so if anything it should move away from the flywheel. It was in the right way round wasnt it? I hope so...it all worked ok..other than the noise when pushing further down.? I'll have to have a look again now .... Gearbox is still out so a quick job to check! Quote Link to comment Share on other sites More sharing options...
glang Posted December 19, 2017 Share Posted December 19, 2017 see if you can find any other contact marks on flywheel or pressure plate Quote Link to comment Share on other sites More sharing options...
mazfg Posted December 19, 2017 Author Share Posted December 19, 2017 Just taken it off...no tell tale marks on flywheel or pressure plate? Correct orientation...so not sure what's been happening here? Quote Link to comment Share on other sites More sharing options...
glang Posted December 19, 2017 Share Posted December 19, 2017 hmmmm, what was the result of the end float check on the crank - did you find movement without it being excessive? Quote Link to comment Share on other sites More sharing options...
Pete Lewis Posted December 19, 2017 Share Posted December 19, 2017 if the clutch disc was fitted the right way round ( the wrong way is likely to foul the flywheel bolts and give permanent drive) then to get the fingers or on a coil cover the release arms to contact the disc springs as shown, there is too much slave travel, so a thought is have you got the right sized master and slave diameters fitted ??Pete Quote Link to comment Share on other sites More sharing options...
glang Posted December 19, 2017 Share Posted December 19, 2017 Its just that those marks on the springs are on the flywheel side (unless the springs can spin round.....) so as it looks like the disc was installed correctly shouldnt have been made by any part of the pressure plate Quote Link to comment Share on other sites More sharing options...
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