What have I done?

[Dave Herrod]

Aagh!

 

I Finally got the gearbox, re-built overdrive , prop shaft and back axle in.  started up and pressed the clutch down;  what a racket!

 

It seems that, as soon as the thrust bearing comes into contact with the release springs, I get a load "tinging" noise . (could be "ting" or a "ding" actually).

 

I assume that something in the release mechanism has come adrift when I was reinstalling the box and is now catching on the rotating clutch assembly, but can't imagine what.  Obviously it all has to come out again (oh joy) but I would be grateful if anyone has had this sort of problem before could let me know what caused it.

 

I have a J type saloon gearbox with a diaphragm clutch and cover plate.  All clutch components new last year and working perfectly before I pulled the gearbvox to remove the OD.  

 

Dave

[Dave Herrod]

All has now been revealed!

 

I discovered that the noise was due to one or more of the bolt heads on the front of the flywheel catching the profiled face of the plate that closes off the lower edge of the gearbox.  Obviously there is a tad too much end float in the crankshaft which allows it to move just too far when the clutch is pressed in.  The reason it didn't happen before is that the cover plate had never been fitted; perhaps I now know why.

 

I only discovered this because I couldn't think how anything in the release mechanism could be causing the noise that I was getting. Therefore, before pulling the gearbox, I sat down and thought very carefully of everything that might move .  (unfortunately not before I'd taken off the propshaft, clutch cylinder and all of the gearbox bolts though!

 

The moral; you never get nowhere if you're too hasty?

 

Dave

[jonlar]

Obviously there is a tad too much end float in the crankshaft which allows it to move just too far when the clutch is pressed in.

Dave, does that mean the crankshaft has to come out - is it the same problem as 6s experience with the thrust washers?

[marvmul]

After the sump has been removed, the thrust washers of the crankshaft can be replaced with the crankshaft (and engine) in place in the 4 cylinder TR engine, I suppose in the 6 cyl. TR engine also.

[rudi]

Are you sure there is too much end float? Maybe the fly wheel is just touching the cover plate because this one is dented? I had this experience after replacing the box and starter. I straightened the cover plate because it was bulged. Turning the engine made a horible noise. Now I know why it was bulged, but not after I have searched a day or so for the reason and after taking out the new starter and calling to the supplier that this one was rubbish because it didn't fit my flywheel. :blush:

[Dave Herrod]

Glad to hear that I'm not alone. It is possible that the plate is slightly distorted.

 

I haven't checked the end float yet and ,working on the ignorance is bliss approach, I'm not going to at the moment! I know that the engine is somewhat worn, leaks oil from most of the oil seals, and probably deserves a re-build next winter.  However, in the meantime I am going to get the car back on the road and use the bl**dy thing!

 

The scouring on the back of the cover plate is actually very slight and in only one place, so I will probably install it with washers as spacers between the plate and the gearbox along with a bead of sealant.  Not very satisfactory from an engineering point of view, but at least I know what I've done and will attend to the underlying problem later.

 

Dave

[CP62]

Dave,

 

It really wouldn't be hard to dress the plate out a little so that it didn't interfere with the ring gear bolts.  If you support the plate around the marked bit (wood on a flat workbench or a partly open vice would probably do it) and then tap gently with a smallish hammer, you will move it a little - enough to stop the noise.  

 

I know it all sounds very imprecise, but once you've tried it you will find steel is quite forgiving.  Start with very gentle taps and check the shape frequently, building up the weight of the taps gradually until you see change occurring.  Once you have moved the offending portion enough, simply refit - no need for washers and sealant.

 

All the best with it,

 

CP62

[Andy Moltu]

I haven't checked the end float yet and ,working on the ignorance is bliss approach, I'm not going to at the moment!

It's not tricky to measure & if the end float is excessive it's easy to address before too much damage is done.

If it's OK then it's only cost a few minutes with a dial guage (More faff & time consuming with feeler guages)

[Dave Herrod]

Thanks for the advice guys.  Andy has now shamed me and i will have a go with the dial guage.

 

Dave

[Nigel Lay]

Hi Dave,

Just to add my twopennysworth I had exactly the same with TS952, the only thing was I put everything together, ran the car up and then fitted the closing plate. I wonder if the bolts holding the closing plate are slightly shorter. I know the endfloat is within spec as I rebuilt the engine myself (perhaps I should say 'it should be within spec!!).

Sorry for late reply, other things getting in the way. TS952 WILL be on the road this year.

Nigel.

ps Will you be going to Powderham this year?

[Dave Herrod]

Nigel,

 

I won't be going to Powderham, but hope to go to the International for the first time ever.  (see my post in the general forum)  The logistics are quite complicated as I have to somehow transport the rest of my family and a caravan to Shepton Mallet first on the Saturday.  

 

Dave

 

Dave

[Don Elliott]

When I re-built my gearbox last summer, I pulled off the flywheel and changed the pilot bushing that fits in the back end of the crankshaft.  When it was all back together again, I immediately noticed an improvement in the clutch action as the former pilot bushing was a bit worn with 80,000 miles on it since I had last replaced it in 1990.

 

It now runs a lot more axial, ie like new.

 

I doubt that the thrust bearings are causing any problems.  They are not like in the TR6.  They are like half moons located about half way along the crankshaft.

 

It's possible that the noise is coming from a worn cross shaft or the bushings where the slave cylinder rod actuates the lever for the throw-out bearing.

 

Don Elliott, 1958 TR3A, Montreal, Canada

[Nigel Lay]

Hello again Dave, may see you at the national. I want to go this year as I missed it last time but the wife will be not long out of hospital so we will see. Glad the car is back in one piece. Will catch up with each other one day - Nigel

[jonlar]

I doubt that the thrust bearings are causing any problems.  They are not like in the TR6.  They are like half moons located about half way along the crankshaft.

Hi Don, this is the same as in the 6 cylinder, but they're at the rear of the crankshaft, near to the flywheel, does that make a difference to how they wear and fall out?

[johnsilver]

Hi all, yep, had the same problem, after doing clutch mod, turned engine on, she fired instantly,terrible racket so switched off, after investigating, found it was closing plate on gearbox, interesting thing is previous owner had fitted it back to front, i refitted it the correct way but did not notice the distortion so hence the racket, after a bit of panel beating all was well. I did notice after taking a few measurments there is very little clearence between flywheel and plate so any distortion to the plate will result in the racket we all seemed to have experienced.

John.