And then it went bang!

[TR4A1965]

So,

 

I had the issue wth my dynamator not charging and that was due to it getting fried as it was next to the header.

 

I found my fan belt had a massive split in it and replaced it at the same time as well as fitting a replacement cooling fan as we had lost a blade on ours. Dynamater was replaced.

 

Today, enjoying a foot to the floor moment there was a loud bang. About 1 minute later the ignition light came on.

 

Fearing a bust fan belt I headed for home.

 

The fan belt had come off.

 

So a refit was started. The belt had twisted inside out.

 

All replaced and straightened out the engine was started (Extra coolant etc)

 

The belt was thrashing around. Turned off the engine and noticed the lower fully had a big chunk missing out of it.

 

We found the missing bit as I went back to the point where it happened (Pictures show the issue)

 

So

 

1: My pulley - looks feeble - should I get some form of uprated one and if so what?

 

2: The fan belt fitted tightly on the pulley wheels and I put this down to the fact that it was all a bit raised and tight down to the teeth. Should I get a narrower belt?

 

Best.

 

Paul.

 

Edited August 28, 2017 by TR4A1965

[Geko]

First your 6-blade fan then the pulley? Looks like something is wobbly. I would check the fan extension, the big bolt and... the woodruff key

[Paul J]

Hi Paul

The paint is also missing from the bottom of the vee in the area of the missing pulley section, has the belt been bottoming out in that area for some reason. Could have suffered belt slip and heat in that particular area.

Paul

[Lebro]

I would recommend the narrow belt solution, together with an electric fan improves things no end .

 

Bob.

[TR4A1965]

Paul, Stef, Lebro thanks.

 

Electric fan not an option - traditionalist.

 

I wondered if I had a week pulley and a too wide fan belt??

 

Just thought?

 

Best.

 

Paul.

[RobH]

What belt were you using Paul , you say the belt was tight - too tight maybe? What do you mean by 'down to the teeth'?

 

The standard pulleys may not be massively thick but they have worked OK for 60 years for many people, so must be strong enough for the job. Perhaps Stef has a point about something being out of line - a cyclic load could have caused fatigue failure maybe. Looking at the first image you posted, the bottom of the broken bit around the circumference of the pulley appears a bit rusty - while the vertical edges of the break are clean and obviously recent. Possibly a crack which has been there for a while and growing perhaps?

[MRG1965]

Hi Paul, I had a similar issue 2 years ago, but I luckily noticed a ticking noise when pulled up at a motorway exit on the way back from Lemans, luckily was only 2 miles from home, but feared it was a cam follow shot. But in my case it was the inner half of the crank pully split about 1/3 around, but still in one piece, looked like metal fatigue in my case. Considered welding up or a replacement, but went with a norrow belt conversion and an electric cooling fan, much better in modern traffic, very happy with the belt conversion and fan.

 

Mark

[AndyR100]

if you want to keep most of the original-look why not keep the regular fan but swap to a narrow-belt conversion.

...... Andy

[Fireman049]

Narrow belt every time!!

 

Tom.

[TR4A1965]

Sounding like a narrow belt conversion is the way forward?

 

Best.

 

Paul.

Edited August 28, 2017 by TR4A1965

[stillp]

Hi Paul

The paint is also missing from the bottom of the vee in the area of the missing pulley section, has the belt been bottoming out in that area for some reason. Could have suffered belt slip and heat in that particular area.

Paul

It would be bottoming though wouldn't it, with the side of the pulley missing in that area.

 

Looking at the first image you posted, the bottom of the broken bit around the circumference of the pulley appears a bit rusty - while the vertical edges of the break are clean and obviously recent. Possibly a crack which has been there for a while and growing perhaps?

Maybe somebody was a bit rough levering the pulley off sometime in the past?

 

Sounding like a narrow belt conversion is the way forward?

 

I'd just replace the standard pulley, unless you want a narrow belt for other reasons..

 

Pete

[Hamish]

Looking at the fracture points the bottom fracture on the radius looks to be a little rusty. Thus may have been on the way out for a while. The belt tension may have "worked" this crack open or flexed it on every rotation thus the wearing on the bottom of the v and the rest breaking away.

Replacing with new should fix it but don't over tighten the belt.

 

Luck that the high speed flying shard didn't do more damage like rad or bonnet.

[TR4A1965]

Just spoken with the Tr Shop and have decided narrow belt.

 

I'll fit it before the weekend and see how it goes?

 

Thanks for all the advice.

 

Best.

 

Paul.

[littlejim]

Why does the width of the belt affect how long the belt or pulley lasts??

[Nigel C]

"Electric fan not an option - traditionalist."

 

Please let me know where you're buying the 1965 petrol from then.................

[RobH]

Why does the width of the belt affect how long the belt or pulley lasts??

"Electric fan not an option - traditionalist."

 

 

The width of the belt of course should have no effect on longevity of the pulley, but the original wide belt is very stiff and may need excessive tension. Fexible wide belts are available which perform just as well as the narrow ones.

 

An electric fan can be concealed on the front side of the radiator if you use a pusher configuration. Hardly visible through the grille.

[PYU940F]

NIgel C

That was a bit harsh. We are all traditionalists. even you, to a certain degree otherwise we would not buy and enjoy cars from a different era. I tend to be in the camp of minimal change otherwise it just becomes a modern car looking like a 60's one.

Each to their own

 

Simon

[Nigel C]

yea I hear you... but there's just some things we cant avoid out there these days and fuel/heat etc is some of them. We do need to adapt and modify or using our cars on a day to day basis becomes very difficult.

[TR4A1965]

Too funny. You have to raise the engine on a TR4A to change a fan belt. Not so with a narrow belt conversion. I'm learning the hard way.

 

Also, traditions for me is about the aesthetic not the pain. Hard to separate the two?

 

I am a narrow belt convert. I still respect other religions.

 

Best.

 

Paul.

[PYU940F]

Nigel C

All I seem to read about are people who modify: Alternators, narrow belts, electric fans, high torque starters, stage 2 cams etc etc, the list goes on and on and the stories of overheating, rough running, unreliability just go on and on. Lift my

bonnet and it is just as it left the factory in July 1967, even down to an unmodified head. I do not overheat, my pulleys

do not fracture and my belts do not break. Please tell me: what am I doing wrong?

 

Simon

[littlejim]

Why does the width of the belt affect how long the belt or pulley lasts??

"Electric fan not an option - traditionalist."

 

 

The width of the belt of course should have no effect on longevity of the pulley, but the original wide belt is very stiff and may need excessive tension. Fexible wide belts are available which perform just as well as the narrow ones.

 

An electric fan can be concealed on the front side of the radiator if you use a pusher configuration. Hardly visible through the grille.

I skipped the narrow belt bit, remember now the gap at the bottom to the chassis makes it hard/impossible to get out/in as has been described. Put in the electric fan.

Went the whole hog and got rid of the water pump and put in an electric water pump.

[Nigel C]

back in the land of the living.....

Simon, you're definitely not doing anything wrong by the sounds of it! I guess mine is compounded by being wrapped up nicely in a GRP tea cozy

[TR4A1965]

Narrow belt kit now fitted - see picture.

 

Was it easy to do - no.

 

Whole process took a day (8 hours).

 

So it seems all good so far but I do need to take the TR for a good run to confirm.

 

Getting the pulleys off was the toughest job.

 

Here's the procedure I followed.

 

Radiator has to come out. Front air cowl has to come out. Then you loosen off the dynamo.

 

1: Remove the dynamo pulley with a hub puller and replace.

2: Remove the water pump pulley with a hub puller

3: To remove the lower pulley you have to take the fan off. Then you have to remove the dog bolt. It was called a dog bolt as it took the hand crank but on a TR4A this does not exist as it is just a bolt. Once the bolt is out you can then use a puller to remove the pulley. It is important to note Top Dead Centre on the pulley and replace with the new pulley and mark. accordingly. TDC is marked on the pulley by a drilled hole. It is mentioned n the workshop manual.

 

 

 

I found some good advice on the TR3 forum on an older post repeated here below and bought a pipe wrench. I can't imagine trying to do this job without it.Great bit of kit.

 

 

"Working from memory, yes, you do need to remove the fan. Mark it so that you can replace it in the same location.

Then, you need a large pipe wrench to hold the fan extension hub and apply the torque to the dog bolt with a long extension.

Sounds bizzare, but I was told by a long-time mechanic who worked on the originals that that's how they did it at the factory, and you can see the pipe wrench marks on the original extension.

Anyway, I followed his advice, and it worked like charm.

On reinstalling it, use the pipe wrench again to hold the extension as you tighten the dog bolt. It's important that the timing mark be correct when you reinstall the crankshaft pulley, so it would be useful to follow the shop manual or Haynes for the full procedure.

It's not complicated, but the manual will point out the points to watch.

Don't overtighten the stud holding the timing chain tensioner spring - it's very easy to strip. "

 

 

[Geko]

Then you have to remove the dog bolt. It was called a dog bolt as it took the hand crank but on a TR4A this does not exist as it is just a bolt.

 

 

 

Hi Paul, looks good, re the dog-swine bolt, on my 4A 66 it was a dog bolt but the first thing i did upon removal is to grind out the dog bit and reshape the flats to a 27 mm hexagonal so as to allow a hex socket to fit in tightly without risking to round the flats

Edited September 6, 2017 by Geko

[Paul J]

Hi Paul

I have also gone the thin belt route, initially though I had problems with belt slip, the belt was adjusted as tight as I thought necessary but still the belt under load would slip. Aerosol belt grip has cured the problem. Interested to know if anyone else had similar problems, I put it down to the polished alloy finish on the vees.

Paul