Noise from gearbox/clutch. Gpw

[Jeff Glasser]

Help! When the clutch pedal is let almost up after engaging first gear with engine running there is an loud 'graunching' noise. It goes as soon as you move off. It doesn't do it after you've driven on, nor does it do it when warm. I've heard thrust bearings make a screeching sound when dry, but that is usual when the clutch pedal is pushed down. There is no sound when pushing the clutch pedal down or letting it up if it's not in gear. Anyone had this problem?

[Pete Ashby]

Is this a new build or has the problem suddenly developed?

Pete

[Jeff Glasser]

It's a relatively new problem Pete, probably caused by lack of use. Restored a few years ago but only done a very low mileage. The sound is similar to a U Boat Klaxon!! (Stop laughing at the back there)

Jeff

[Pete Ashby]

Could possibly be a dry pilot bush in the fly wheel Jeff. 

I had that once on a jeep I did some years ago it had the same symptoms you describe, I solved it by jacking up the back end of the jeep a put one very very light squirt of WD40 onto the input shaft and left it over night on the blocks to let the WD40 creep down the splines and shaft towards the bush next morning took the truck off the jacks and problem was solved but do not over cook this or the WD40 will drip off the shaft and contaminate your clutch lining........not good 

Pete   

Edited October 1, 2018 by Pete Ashby
missing word

[Jeff Glasser]

Pete, thanks for that, I have my suspicions that it might be that as I'd never heard a thrust bearing make the noise in question. Is what you refer to called a 'spigot' bearing? I assume that to do as you suggest access is gained via the bell housing inspection plate?

I apologise for my lack of knowledge on these matters but I spent most of my working life repairing and painting motor vehicles, clever people did the mechanical stuff! 😊

Thanks again. 

Edited October 2, 2018 by Jeff Glasser
Removed e-mail address

[Pete Ashby]

3 hours ago, Jeff Glasser said:

Pete, thanks for that, I have my suspicions that it might be that as I'd never heard a thrust bearing make the noise in question. Is what you refer to called a 'spigot' bearing? I assume that to do as you suggest access is gained via the bell housing inspection plate?

 

Yes that's right Jeff on the jeep it's a plain sintered phosphor bronze oilite bush this type of bush should be soaked in clean engine oil over night then drained and wiped before fitting and reaming to size.

The sintered bronze is porous and absorbs a small amount of the oil if the bush was not oiled and/ or reamed to fit and/or has dried out with standing or a combination of all three it will drag on the spigot of input shaft and set up a god almighty wail as the clutch is let in when everything warms up the bush will probably expand just enough to let the shaft run free in extreme cases it can appear like clutch drag so that you are unable to get a clean gear selection as the primary shaft will keep turning with the flywheel even with the clutch down.

As you suggest go in from the top of the bell housing do not use ordinary oil it's too viscous and will just fly off the shaft when it turns and get all over the clutch plate,  use something like WD40 and don't fire hose it in,  be very circumspect with the application  and leave the truck jacked up nose down for at least 12 hours before trying to start it. 

Let us know here on the forum how you get on,  or if you find it's something else entirely come back and tell us what is was,  this sort of information is of use to all of us when trying to sort out these irritating problems.

Pete

Edited October 1, 2018 by Pete Ashby

[Jeff Glasser]

Thank you Pete for explaining that to me. I definitely believe by your descriptions that you've hit the nail on the head. I shall get this looked at using this knowledge as soon as possible and will report back my findings on here. Here's hoping for a good result.

Thank you again. Best regards, Jeff'.

[Jeff Glasser]

Hello Pete, 

I expect you thought I'd fallen off the radar! sorry about that. I did as you suggested ie jacking it up and giving the splines a gentle shot of WD 40. It stayed like that for about a fortnight until I could let it down again having not been at all well with chest problems. Anyway, today it was pleasant enough to get out to the garage and try the jeep up and down the drive. Sir, I owe you a drink as said jeep was silent when letting the clutch up (several times) You can't know how good this made me feel as I'd resigned myself to taking the engine out to remedy the fault. I hope it solves the problem, but if it does it again at least I'll know a cure even if temporary. Thank you again. I hope others can benefit from this knowledge.

[Pete Ashby]

Well done Jeff thanks for coming back with the result always useful to know the outcome of this sort of problem,  pleased you have had a positive result  

It's a good example of trying the easy to do stuff first before getting into the hard core rip it all apart phase. 

regards

Pete

[Jeff Glasser]

Yes, thanks again for your help. I had asked many 'knowledgeable' people about the problem over the last two years to no avail. I posted the original question  more as a last resort. 

I hope our paths cross one day.

Jeff