Belve making horrible screeching noise

db · Post by db » Mon Oct 17, 16 4:48 pm

This does not sound good

Last time out I drove it a couple of hundred miles with no issues. I played a bit but never caned it or used the nos.

I just took it down the drive to go pick up the kids from school and as I'm creeping along the driveway it starts squealing like the fanbelt is slipping.
I pulled out onto the road with a little more throttle and the sound suddenly became a horrible metallic screeching, very loud!
Back in the garage now, I need to investigate so what's the most likely cause do you think?

If I turn it over by hand it sounds like a metal - metal squeak. The engine seems to turn ok.
I'll go pull the plugs now and turn it again.
I'm thinking either clutch/ flywheel, or maybe it's turned a crank shell?
Do I drop the gearbox or the sump first?

Blue · Post by **Blue** » Mon Oct 17, 16 5:20 pm

I assume you've taken off the belt to eliminate the alternator and water pump?

Pete · Post by **Pete** » Mon Oct 17, 16 5:51 pm

Get someone to depress the clutch while you turn it over as it may help diagnosis.

I think more research is needed. Alternatively video it and put it up on 'interweb and post a link here to it.

Dave999 · Post by **Dave999** » Mon Oct 17, 16 5:53 pm

if you had done a bearing on the mains the damage is done it just turns nicely, because it has already welded nasty mess all over the crank journal and that has ground a nice furrow into what's left of the shell

and your oil pressure goes and depending which main is knackered you start to destroy a couple of rod journals.

if its a rod it either knocks or it seizes bends and exits through the side of the block.

alternator aircon or power steering would be other candidates for squealing

Dave

Pete · Post by **Pete** » Mon Oct 17, 16 5:55 pm

If you spin a bearing (unlikely) you can still have good oil pressure so that is no guide....

Pete · Post by **Pete** » Mon Oct 17, 16 6:02 pm

My money is on a seized Alternator.

Dave999 · Post by **Dave999** » Mon Oct 17, 16 6:04 pm

do you run an oil slinger on the front of the crank
normally it is held away from the back edge of the timing cover seal by the boss of the balancer and is kept in position by a slot for the key

if the balancer moved forward the slinger can move about, wedge at a weird angle and its edge runs on the edge of the metal case of the crank seal in the timing cover.

but that tends to sound like mice being tortured.

if you put the slinger on backwards it can damage your timing chain, that too would make a noise.

so can any bearing behind your cam sprocket
or on a none supported sprocket the back of it wearing into the front of the block and the front driving into the timing cover, but only when the chain becomes baggy enough for cam float to become an issue

your timing would be all-over if this was the case cam and ignition

all based on hemi 6 fun you can have...but I'd imagine the v8s are similar in some way...dizzy runs off the cam doesn't it?.

db · Post by db » Mon Oct 17, 16 7:12 pm

Thanks all!
Fanbelt is off, squeal is still present.
Slack of me but in my flustered state I didn't look at the oil pressure. Now I daren't start it.
There's no top end damage I can see and the plugs are undamaged and there's no metal there that shouldn't be.

I'll try it with the clutch released next, then I guess it's off with the sump. Luckily that's easy with no K frame.

db · Post by db » Mon Oct 17, 16 7:50 pm

Noise still there with clutch released (turning the motor over by hand)
Next it's oil out, sump off

shovelheadrob · Post by **shovelheadrob** » Mon Oct 17, 16 8:24 pm

Is it the release bearing, check you have correct free play in the clutch linkage.

latil · Post by **latil** » Mon Oct 17, 16 8:29 pm

Not the starter staying engaged?

Mick70RR · Post by **Mick70RR** » Mon Oct 17, 16 8:32 pm

Has the crank damper slipped back against the timing cover. It happened to me with a stock original damper. It made a tinny metalic scraping sound. New damper fitted and all was well again.

db · Post by db » Tue Oct 18, 16 12:46 am

Thanks guys I'll look into your suggestions.
I've dropped the sump and windage tray and there's no sign of swarf or shiny bits in the oil.
It's all on hold for now for personal reasons but I'll get back to it asap.
Cheers

db · Post by db » Tue Oct 18, 16 6:45 pm

Damper is eliminated from my enquiries, as is the starter- now the sump is off I have a clear view.
Lying under it and turning it slowly, it sounds like it's around the flywheel or rear of the crank.

I'll get a second opinion before I dismantle further.
I do need to drop the gearbox to sort 2nd synchro so it's not wasted effort.

db · Post by db » Wed Oct 19, 16 5:31 pm

shovelheadrob wrote:Is it the release bearing, check you have correct free play in the clutch linkage.

Rob wins

I don't know if the missing retaining spring affected it or just bad adjustment but bearing is pretty seized.