Does anyone know what is involved in fixing this problem?

 

The engine is a small port 4age. I’ve only just brought it and apparently there was a problem with the old harmonic balancer key way having too much clearance. The harmonic balancer I have looks alright but I’m a bit concerned about the key on the actual crank. It looks a bit worse for wear.

 

I haven’t got the new balancer on yet as the key would need to be filed down a little I think as it’s hitting the balancer.

 

It looks kind of bent and worn so I’m thinking it would just get worse until it brakes.

Never ever ever file down the woodruff key.

 

Spend a few bucks and go buy a new one.

 

Its that shape and size for a reason as it holds the timing gear pulley onto the crank.

That's some nasty corrosion. If you're lucky you'll be able to get the timing gear off the crank. WD and some pullers... I don' think the old pry and tap with a hammer will work there. Then with some vice grips you might be able to pull the key out of the crank with any luck. Toyota should have the part number for a new key with any luck.

Ok just learnt that the key is actually removable :y:. Sounds like it will be all good then.

 

Thanks a lot.

Be very careful removing it.

 

I remember a thread a while back on Toymods where the nose of the crank sheared off a 4AGE whilst driving down the freeway. I think it might have been Hen. And from memory it was a smallport.

 

Yes, here is the thread.

Just found this article that’s interesting

 

One pic shows a 4ag crank with a bigger key way milled into the crank for a bigger key.

 

here

Yeah, be very careful with the way that you remove the old key and install the new key. Clearance and fit are very important here.

 

Also, what type of harmonic balancer are you going to run? A stock toyota balancer or aftermarket?

 

I decided to machine the second row(power steering) off my stock balancer as I figured I didn't need it.

 

I then later purchased a nice shiny aluminium crank pulley, and was planning to run with that until someone informed me (I should have thought of this myself :D)

 

that the aftermarket pulley would change the rotating mass of the crank, and could potentially cause big problems.

 

I then had to source another new stock pulley to keep everything factory..

Yeah, be very careful with the way that you remove the old key and install the new key. Clearance and fit are very important here.

 

Also, what type of harmonic balancer are you going to run? A stock toyota balancer or aftermarket?

 

I decided to machine the second row(power steering) off my stock balancer as I figured I didn't need it.

 

I then later purchased a nice shiny aluminium crank pulley, and was planning to run with that until someone informed me (I should have thought of this myself :D)

 

that the aftermarket pulley would change the rotating mass of the crank, and could potentially cause big problems.

 

I then had to source another new stock pulley to keep everything factory..

 

 

 

So you’re only going to run the stock harmonic balancer. Not an after market crank pulley.

 

Then I’m guessing you can’t run a harmonic balancer and an after market crank pulley like this…

 

T3 Crank Pulleys

 

 

I see they have double row too

 

I kind of know what a harmonic balancer does but need to do some more research. Don’t even have a workshop manual for the 4age yet so…

 

Yeah this is the balancer I got with the engine. It was not attach but I’m guessing it’s stock Toyota.

Looks stock to me. Also handle it carefully as the edges chip of easily.

 

I am no expert but I would have thought altering mass on the front of the crank would be no different to altering mass on the rear of the crank (flywheel)?

Yeah - I am running a stock standard harmonic balancer.

 

 

I am no expert either with these things, but last time I was out at Road and Track in Ipswich talking to Terry I showed him some images of my detailed engine

 

with the T3 crank pulley on it, and he said I should take it off, or risk doing some damage to the crank/bottom end.

 

 

From what I understand those machined aluminium crank pulleys are more for racing purposes where weight reduction is crucial and everything will be balanced with the engine.

 

Those aftermarket pulleys are a one piece unit, and don't have the rubber damper in the middle that is the whole purpose of the harmonic balancer - to prevent resonant vibration in the

 

crankshaft that can be quite damaging to the bottom end.

 

 

I didnt want to risk it for something that I didnt know too much about, and in my case would be for purely aesthetic purposes, but realistically is not that visible in a KE10 4AGE setup,

 

as the radiator sits pretty darn close to the engine in my car.

 

 

My original stock harmonic balancer was a double row setup, and after I got it lightened it looked the same as the one in your photo. The stock toyota one I have now has 2 rows.