Hi Richard If you are suffering from a rattle take a look at RPI Engineering website and read what they say about LT77 and R380 gearboxes, if yours is a plus 8 it will have one if these is after 95 it should be a an R380 but may depend on what Morgan had on its shelves at the time. Anyway I believe, from what RPI say, that both these gearboxes have a conical bearing at the end of the main shaft that is carefully shimmed when built. There are 2 issues, if Ep80 or ep90 (ATF) oil has been used it causes premature wear of the conical bearing then allows the main shaft to move and gears to not engage properly and then whine or rattle, rhe other is it is not a great design idea and is a weakness. They recommend Castrol Syntrans Multivehicle 75W-90 Fully Synthetic MTF (Replaces SMX S 75w-85) I suspect the act if pressing the clutch is putting rearward pressure of the main shaft forcing it back in the bearing an making them align better.
I think it would be worth giving RPI a call as they are experts on v8's and transmissions, and could save a lot of time, effort and money, especially as you have the engine/gearbox out. They should be able to tell you the amount of free play tolerance on the main shaft and how to check it. I hope this helps. My noise has strangely completely disappeared, I have done a test run in all gears and listened very carefully and nothing, I will continue to monitor carefully, I am going replace the oil with the SMS-X as I do not know what is in mine and want to get the best from the gearbox. Regards Adrian On 22 Jul 2012, at 10:55, Richard Smith <[email protected]> wrote: > We have spoken before on here about various noises, one of which was a rattle > which disappears when slight pressure is put on the pedal. I think this might > just come from simply free play in the cable, having now taken my engine out, > can see nothing, or feel nothing, wrong with the thust bearing. > > Richard S > www.british-red-sportscar.co.uk > www.greystones.co.uk > www.unstonegreen.co.uk > www.mogpix.com > > > > -----Original Message----- > From: Martyn J Culling [mailto:[email protected]] > Sent: Sun 22/07/2012 10:23 > To: mogtalk2 > Subject: RE: [mogtalk2] Thrust bearing noise? > > Addendum > > I remember now, my first car had a failing thrust bearing. Made a dreadful > screeching noise when hot, but never failed to operate. > > Eventually replaced the whole clutch as I was sick of the noise and > convinced it would all fall to bits. > rgds Martyn > > > > > > From: Martyn J Culling [mailto:[email protected]] > Sent: 22 July 2012 09:24 > To: mogtalk2 > Subject: Re: [mogtalk2] Thrust bearing noise? > > > > Adrian > > I know you said thrust bearing - and I replied in that vein but actually now > I think about it, my failure was a pilot bearing. But both thrust and pilot > bearings are both inside the clutch and are both operating when you press > the clutch pedal and failure of either is a similar repair job. > > My bearing was wreaked. The rollers had made a bid for freedom and jammed > the gearbox shaft to the crank. I was shown some of bits by the garage; I > think they thought I'd find the tale hard to believe! > > Do you know a good mechanic? The first sensible step is asking the opinion > of someone who a) has good hearing and b) has plenty of experience of that > engine. > > I've got a feeling the problem may not be the pilot or the thrust bearing at > all, may even not be that significant, but I'd definitely be looking for a > good second opinion from a good mechanic. > > Mileage is not really a clue. As rule, both pilot and thrust bearings last a > good long time and while failure is uncommon, a failure at 3000 miles as I > had, can occur. > > While I can't remember the exact amounts, the cost of my bearing was about > 80p, and the labour £80 (it was years ago...). > > For those who are uncertain of what bearing is what, the pilot bearing is > the bearing between the gearbox and the crank - the one you have fun > engaging when you put a clutch back together and a thrust bearing is the > bearing that presses on the clutch diaphragm to release the clutch. > > rgds Martyn > > > On Jul 21 2012, Adrian Slade wrote: > > Hi Martyn > > Was the one piece crank with main shaft due to the bearing failing and then > no clutch? > > Mine is very odd as it was a knock, knock and then nothing, and as soon as I > reversed no noise at all, and since then having driven 20 miles it is still > silent. I am a little worried by this. The car has only done 24k miles and > the clutch feels fine, the only thing I can think of is the bearing has > dried out at some point and is starting to fail. What do you think? > > Regards, > > Adrian > > Sent from my iPad > > On 21 Jul 2012, at 16:15, Martyn J Culling wrote: > >> Adrian >> >> From personal experience - be careful. My crossflow thrust bearing made a > noise, and less than 1000 miles late I had a one piece crank and gearbox > main shaft. >> >> Over 100 miles from home, on a motorway, on a bank holiday Saturday, I > pulled into a service station and could not change gear. RAC man managed to > find a garage to fix it, and really, the price for a big job on a Saturday > was a bargain. Plus I could carry on and do another 300 miles and go on my > holiday - just made arrival many hours late. >> >> rgds Martyn >> >> On Jul 21 2012, Adrian Slade wrote: >> >> Hi >> >> Just got trusty Rosie (plus 8) out for a run to Sidmouth with she who must > be obeyed in passenger seat. Got 200 yards and then funny nocking noise, > initially I thought oh no a stuck valve, the I noticed clutch depressed a no > noise, ah ah! >> >> So I stuck it into reverse moved back a bit to turn around an then into > 1st and the noise had gone. So I moved forward and back and still no noise, > so great. We continued on our journey at up to 60 and all was fine there and > back. >> >> So now I am home this is praying on my mind a bit, I cannot detect any > noise from the gearbox, or the nocking noise, so my initial thought is a > small stone might have got into the clutch workings am putting it into > reverse freed it out (not sure if there is external access holes for this to > happen). >> >> Has anyone else experienced anything similar, or is it a sign of a failure > looming possibly? >> >> Regards, >> >> Adrian >> >> Sent from my iPad >> >> >> ------------------------------------------- >> View posts on The Mail Archive >> http://www.mail-archive.com/[email protected]/ > [http://www.mail-archive.com/[email protected]/] >> >> Modify Your Subscription: https://www.listbox.com/member/? > <https://www.listbox.com/member/?&;> & >> Powered by Listbox: http://www.listbox.com >> View posts on The Mail Archive > http://www.mail-archive.com/[email protected]/ >> Modify Your Subscription > > > > ------------------------------------------- > View posts on The Mail Archive > http://www.mail-archive.com/[email protected]/ > [http://www.mail-archive.com/[email protected]/] > > Modify Your Subscription: https://www.listbox.com/member/? > <https://www.listbox.com/member/?&;> & > Powered by Listbox: http://www.listbox.com > > View posts on The Mail Archive > http://www.mail-archive.com/[email protected]/ > > > > <https://www.listbox.com/member/?&; > 5> Modify Your Subscription > > <http://www.listbox.com> > > > > > > > ------------------------------------------- > View posts on The Mail Archive > http://www.mail-archive.com/[email protected]/ > [http://www.mail-archive.com/[email protected]/] > > Modify Your Subscription: https://www.listbox.com/member/?&; > Powered by Listbox: http://www.listbox.com > > > > > ------------------------------------------- > View posts on The Mail Archive > http://www.mail-archive.com/[email protected]/ > [http://www.mail-archive.com/[email protected]/] > > Modify Your Subscription: https://www.listbox.com/member/?&; > Powered by Listbox: http://www.listbox.com > <winmail.dat> ------------------------------------------- View posts on The Mail Archive http://www.mail-archive.com/[email protected]/ [http://www.mail-archive.com/[email protected]/] Modify Your Subscription: https://www.listbox.com/member/?member_id=22459785&id_secret=22459785-4a39ddf8 Powered by Listbox: http://www.listbox.com
