Annoying knock from camshaft front pulley area

[David Stepney]

Commenting on Howard's post, I have no problem with Loctite in its various guises, provided it is used wisely. Indeed, a number of modern chemical products help us in keeping our elderly cars on the road. For instance, the inner race of the rear main on my own car is secured to the crank with a blob of Loctite Bearing Fit, as it was at best a good push fit on the end of the crank, as the original bearing had spun. Fortunately, the replacement bearing is of the 'crowded roller type, so, if I have to minister to the bottom end again, pulling the outer race will cause all the rollers to fall out, so i could still get the crank out and sort out any recalcitrance on the part of the inner race on the bench.

Most Loctite materials also weaken with heat (about 300C if memory serves me correctly), but you need a really good plumbers brazing torch (like a Rothenberger or similar) to get enough heat onto a flywheel.

My own experience with Loctited flywheels was from many years ago, when I had my special. In my youthful enthusiasm, I loctited the flywheel to the end of the crank, and, subsequenty, when I tried to remove it to reline the clutch, managed to pull the thread out of one of the threaded holes in the flywheel that supports the flywheel puller. You can imagine the fun I had getting the flywheel off after that!

[Howard Wright]

Agree entirely David.

As an example of when Loctite 660 would have been useful is when I built the engine of my first special. Exuberance and ignorance caused the flywheel to be lapped up until it was hitting the cam bearing  . What is more exerting uneven pressure during lapping caused a huge run out, a recipe for a loose flywheel within 500 miles!

Cheers

Howard

[Lowbarn]

Good garage session this morning.
Engine out again.

Should be a couple of pictures attached.
Flywheel nut nut came off very easily and the flywheel came off With it?
I thought they’d were supposed to be very tight?

Anyway clutch looks new and no play in the crank bearing.

Interestingly there is no oil thrower and the back of the flywheel seems to be touching to outer casing of the bearing.

I’ll get a new key and nut tab tomorrow. Might try loctiting the nut retaining tab to the flywheel as the one I took off couldn’t be moved round by hand.
Not sure about putting grinding paste on the crank taper. I cannot see how I would keep it out of the bearing.
           

[Howard Wright]

Hi Lowbarn

I would be very tempted to take off the retaining plate and test fit the flywheel. I can’t remember if there is room to get a feeler gauge between flywheel boss and race but if not put a small dab of plastercine  or blue tack between the flywheel boss and the bearing race.  The reason for this is to ensure that when you tighten the flywheel nut you still have a little room to ensure the flywheel pulls up hard against the taper. You should still have a little blu tac between the flywheel and race indicating the space you have for the taper to pull up. 

Ideally the oil thrower has tiny dimples that can flatten as you tighten up the nut allowing full engagement of the taper and also holding the thrower. However if you don’t have the thrower it is possible that the original engine builder was happy to trust the modern lip seal.  Others may comment on leaving the thrower out but I think any gap between flywheel and race may allow the inner race to move and it may spin on the crank journal later down the line.

I wouldn’t use grinding paste with the bearing in place. As mentioned before a light smear of Loctite 660 will do the trick.

Cheers

Howard

[David Stepney]

I think that you may have found the problem. The boss on the flywheel is contacting the rear bearing before the taper has gripped. As  Howard, suggests, make sure there is clearance between the boss and the bearing inner race. Plastigage is the stuff to use for clearance in inaccessible places.

I wouldn't worry too much about using grinding paste with the crank in situ. You will only need the lightest smear of paste on the taper, but make sure that you have got that clearance between the flywheel and the bearing. Once you have, I would trial fit the flywheel, tighten it and check the fit before going much further; from your photos, the taper faces don't look too bad.

If the boss need taking down, the best way is with a lathe, but I have filed them in the past. It depends whether you can file flat.

[Terrytuned]

The new keys allways sit too high with the flywheel fitted there should be clearance between the top of the key and the keyway, I don't use a lockwasher as they are too soft just just do nut up tight with locktite. (tight is 150ft lbs) Terry.

[Colin Reed]

HI,
Looking at the retainer plate it looks new reason I ask is the flywheel is rubbing on the oil seal as well so when you get the depth for the flywheel right I think you will need to skim rear of flywheel  for clearance of the seal.

Colin 
NZ

[Lowbarn]

Thanks once again for the advice Gents.

I measured up best I can last night and the flywheel definitely gets very close to touching the bearing and certainly does touch the face of the seal.
Not convinced it’s tight on the taper at that point either.
I also noticed that the nut tightens before reaching the end of its thread.

I’m going to remove the bearing carrier this morning and try to see if the flywheel actually tightens onto the taper or the bearing face.

At least I’m feeling more confident that I’ll get the car to Morton now.

Regards,
Richard.

[JonE]

The new keys allways sit too high with the flywheel fitted there should be clearance between the top of the key and the keyway, I don't use a lockwasher as they are too soft just just do nut up tight with locktite. (tight is 150ft lbs)  Terry.

Terry - which loctite would you be using here - one for heat release or something just with some threadlock? Are you suggesting that the lockwasher might be cause for loosening flywheels because of them gradually 'moving' with pressure?

[David Stepney]

HI,
Looking at the retainer plate it looks new reason I ask is the flywheel is rubbing on the oil seal as well so when you get the depth for the flywheel right I think you will need to skim rear of flywheel  for clearance of the seal.

Colin 
NZ

Well spotted Colin. I missed that!. Looking at the photos closely, you can see it.