TR2/3/3A Loud scraping sound in clutch area

[GTP1960]

this loud intermittent scraping sound occurs when the car revs past about 1600-1800rpm.
Scraping sound occurs in or out of gear.
clutch in or out.
but not at idle.
not sure about higher rpm's.
sounds like it is in the clutch area.
Transmission oil level ok
(TR6 type A OD tranny)
engine oil level ok.

sounds something like a lawnmower blade skimming over something it shouldn't.

any advice appreciated.

 

[Geo Hahn]

Since it occurs with the clutch in I would be looking for something interfering with the engine or flywheel.

My prime suspect would be the sheet metal inspection plate at the lower end of the bell housing. Easy to remove and see if the noise goes away.

They can sometimes be a too close of a fit - may even be able to install them backwards with noisy results.

 

[mrv8q]

Wonder if something is interfering with the fan? I had a funny noise a while back that turned out to be the coolant overflow hose tangling with the fan. Just a thought...

 

[charleyf]

If you are sitting in the car your ability to locate the source of the noise is pretty slim. If you can put it up on a lift and safely get under it while it is running you will improve your chances of finding the source.
Charley

 

[GTP1960]

Wonder if something is interfering with the fan? I had a funny noise a while back that turned out to be the coolant overflow hose tangling with the fan. Just a thought...

I replaced the mechanical fan. Only have a electric now.

however I will check the alternator shaft fan & the timing chain more closely.
it definitely sounded like contact caused by something spinning.
I have been reluctant to re create the event:
once I increase the rpm's to the point the noise occurs I shut it down.

I guess I'll need to run it until I can locate it exactly.
(& get mentally ready for a tear down.)

 

[CJD]

Since it occurs with the clutch in I would be looking for something interfering with the engine or flywheel.

My prime suspect would be the sheet metal inspection plate at the lower end of the bell housing. Easy to remove and see if the noise goes away.

They can sometimes be a too close of a fit - may even be able to install them backwards with noisy results.

+1. Easy to check too.

 

[GTP1960]

Since it occurs with the clutch in I would be looking for something interfering with the engine or flywheel.

My prime suspect would be the sheet metal inspection plate at the lower end of the bell housing. Easy to remove and see if the noise goes away.

They can sometimes be a too close of a fit - may even be able to install them backwards with noisy results.

any step-by-step instructions on tranny removal (or YouTube) out there?
i haven't done that in 30 years.

also if I am removing the transmission should I be doing any other PM?

thx.

 

[Geo Hahn]

...if I am removing the transmission should I be doing any other PM?...

Just to be clear - the inspection plate I suggest you remove does not require removal of the gearbox.

Item 62 in this illustration:

Just 4 bolts holding it on there, as I recall 2 of them also secure the clutch slave bracket.

I'll confess - I drove for years w/o that shield in place. Not suggesting this is a good idea but noting you should be able to take a test drive w/o it and see if the noise persists.

 

[GTP1960]

Thanks for posting that diagram.

i guess I was invisioning an inspection plate to look something like a vin # plate with words like "inspected by Joe" on it.

 

[CJD]

The plate is stamped steel, and can easily get knocked inward if you run over anything that gets kicked up. The middle top of the plate has a lip that only clears the back of the crankshaft and flywheel by 1/4" on a good day, so any damage will allow it to scrape and make a nasty loud noise.

Once you have cleared that cover as a cause, then we can look at more invasive possibilities. But no need to worry about pulling the tranny...yet!?!

If you remove the clutch cover and still hear the noise, the second possibility is to look inside the area covered by the cover to look for metal parts that broke off the clutch, the clutch release mechanism, or the starter motor. They would fall into the bottom of the bell housing and be very obvious.

Bar any problem there, the next will be to have someone rev the motor while you look in the engine bay to localize where the sound is coming from. Valve train would be my 3rd most likely guess. 4th would be the chain tensioner on the front of the motor. These problems can still be fixed with the engine and tranny in place. Any clutch problem cannot.

 

[GTP1960]

After working the accelerator from under the hood, & trying to localize the sound, I'm thinking the scraping noise may be from the water pump.
though it only has about 1000 miles on it (a five vane TRF, I think) & it's not leaking.

no noise at idle
but sounds painful at about 1800rpm.

when a water pump goes bad can it make a grinding/scraping sound?

i was using a stethoscope, but it was inconclusive to my ears, just transferred the sound thru the housings.

 

[Geo Hahn]

For a test you can remove the belt and (briefly) run the engine - see if the noise goes away with the water pump out of the loop.

Yes, they often make noise as a precursor to failure -- but another nearby source of noise is the timing chain tensioner.

 

[GTP1960]

Well I found the problem.
it is the main crank pulley. I had replaced it with a Moss vibration dampener type two years ago.
Completely wallowed out & wobbles on the shaft.. I hope my drive shaft is made of tougher stuff.

BTW: thanks for the advice Charley, Geo & everyone.
it lead me to the problem.