300E 2.6 1990 with Sheard Crank shaft key.
 

Hi guys,

I'm looking at the above car and the crank shaft key has sheard because the large bolt came loose that holds it on the crank.

I have a couple of questions,

- Has any one got a pic of the hub that slides onto the crank behind the harmonic balancer ? I think mine has worn out as it rocks on the crank shaft. Part of the key is still wedged in the groove. Might be able to compare the groove to mine before I order any parts.

-Has any one got a pic of the end of the crank in good condition ? From what I can see it is in good condition, the groove is there for a key and looks good. No burrs, etc.

-Is the hub part of the balancer or can it be purchased separatly ?

Thanks in advance.

Josh

If the key sheared and the balance and pulley moved from where they are supposed to be fixed to the crankshaft while the car was running, it would almost certainly have bent a few valves at the very least.
At worst, there could be quite a bit of severe damage including bent rods, cracked/damaged pistons, etc.
Obviously you can't turn it right now to find out if it moves freely.

Also, if the crank bolt came loose, You can be pretty sure that it had been worked on recently, probably by someone not skilled in good shop practices (proper torqueing) and not very thorough.

If you're looking at this car to buy, I'd be VERY skeptical.

The lower chain sprocket has its own keyway, the pully has its own additional key , so if the engine runs and sounds normal its probably ok , the hub is available seperately, you will most likely need the new key , new hub, but you need to check the crank it could of worn the keyway too big, in which case your going to need a new crank

It's only going to be a project car so I've cut my losses and brought it.

I'm going to have a closer examination tomorrow, so Ill post some pics of the key way on the crank (on first look it looks ok).

I've cranked it over and it sounds fine, so that's one hurdle jumped over.

More to come.

Nulu - You're absolutely right, the pulley only runs the drive belt/accessories, the timing chain is a separate affair.
My bad!, sorry for the incorrect response kiwi-bloke.

No Problem.

Had a closer look and the key way is largley intact. There is a tiny chip in the centre of the keyway.

I propose I will get a second hand harmonic balancer / hub as it looks like the current one is damaged. I can get one for $50 NZ so its not a major cost.

If this proves to not fit properly, I have two options.

Second hand crank - just getting avaliblity and price locally.

OR

Engine swap - Can get one pretty cheap.

My question is, in terms of effort is change the engine, or the crank more involved?

From what I can see and engine swap is straight forward, the crank swap is not.

Sounds about right. How plentiful are spare parts / wrecked cars over there in NZ?

Wrecked cars are pretty easy to source in the main cities. You just need to know where to look.

For instance I've seen a couple of engines for 500 to 800 NZ dollars.

What would be involved in a swap?

-Unbolt engine mounts
-Unbot bell housing
-disconnect earth straps, fuel delivery lines, electrics....


Anything else ?

UPDATE
 

New (Used) Balancer and hub arrived today.

Checked it out, slides over the front of the crank and sits pretty snug.

Doesn't fit Really Really tight as I've read else where, but it definatly doesnt have any play once on there.

Also had a quick compare of the keyway vs the new key. The new key would fit pretty tightly in there.

My only concern thus far is, that at the back of the keyway, there looks to be a chip.

Did'nt get around to pulling the rad out last weekend, so I'll add some pics once I get to it.

Weather has been absolute rubbish!

Progress
 

I've pulled the Evaporator ?? (part of the air con) to get good access to the crank.

next question is, how do I put in the key ? Obviously I know where it goes, but it wont push in by hand ? Do i need to tap it in with a hammer or such forth ?

I've confirmed there is a small scrape near the back of the keyway - but it looks as though the key will fit tight.

Also, in terms of the evaporator - didn't really know what I was doing with this, so i bleed out the gas using the "small valve" and then just disconected it. When replacing is it as simple as recharing the AC ?

Hi
not unusual for Woodruff type keys to be a tight fit, you don't want them wobbly! A few light taps with a drift should seat it, any more and it may be time to check it with a micrometer - I have used a stone to hone them in on bike engines. Minor chips in the seat shouldn't be a problem as long as everything goes in straight

cheers!

Thanks Ill give it a try this weekend.

Has any one got a picture from the front of the crank ?? IE - of the oil seal.

I'm not sure if mine looks correct.

Hope someone can help

I recieved the car with the balanacer removed. When they removed it - would the oil seal have to have been removed with it ??

I think it has been removed but I'm not sure what it looks like with it installed

ANd last question - can the crank bolt be used more than once ??

Turns out there was a burr on the front edge of the keyway. The part that I thought was chipped is actually intact.

I've filed down the burr and it look set for a good fit. There maybee some slop - but we're talking like quarter to half of a mm.

On a side note, i dropped the key into the sump, so Ill try and fish out with a magnet tonight.

Josh

Ordered a new crank seal.

Questions left are :

Is the crank bolt a stretch bolt ? Can it be re-used ?? Who has reused theirs?

What is the torque value for the crank bolt ?

I thought I'd update this for future Searchers. Installing Harmonic Balancer on M103.

This is the process I followed:

Drain Radiator.

Remove Fan shroud.

Disconect Radiator hoses, trans cooler hoses.

Remove Radiator.

Remove Aircon.

Remove fan and pully. Use the small hole in back to lock, or a pair of vise grips. (Later for me)

Clean up crank nose - used a small box file to remove burrs on the key way. It was burred where the old key have broken and spun. Luckily the damage was minor.

Checked that key was a tight fit, there was no play, but it would fall out.

Replace Main seal. Pry the old one out with a screwdriver. Install a new one using a block off wood with a hole in the centre for the crank to pop through. Tap the seal in.

Place the Key in the slot.

Start sliding the hub over the key. The key will try and push out the back.

Once the hub is half way over the key, tap on with a block off wood. Its a damn tight fit.

Put main crank bolt in to hold hub on. 300NM is the value used to tighten. From what I have found out the bolt isn't a stretch bolt. I reused and have has no issues after several hours of running.

I locked the crank by using a 3 mm rod through the teeth in the ring gear at the torque converter.

I inserted and used a jack to hold it against the ring gear.

Bolt balancer to hub.

Bolt pulley to balancer.

Replace Fan pulley, fan.

Replace fan belt.

Install Aircon.

Install Radiator.

Install Shroud.

Fill Radiator.