crank chewed out

[DilboBaggins]

G'day guys, we have a 1999 2.8lt turbo diesel patrol and the harmonic balancer key way broke and chewed up the crank. So id say we need a new one :/ im in perth (wa) and am trying to find the cheapest one, has anyone had this problem and got a new cheap crank? If use have please message me where or comment. Cheers

[DilboBaggins]

Or would it be worth getting it grinded down and welded? What is the reliability of this if anyone has done it? Cheers

[happygu]

I dunno and I hope I am wrong, but I think you may struggle to find anyone with a good second hand one, as it seems to be one of the weak points on the 2.8.

I think you would be best chatting to a toolmaker/fitter & turner, to see if they can weld it and grind out a new keyway and ask how much ...

[DilboBaggins]

Well I rang nissan, they quoted 2k, so I rang patrolapart and they said they have good second hand ones for $500 so I rang an engineering joint and they said they should be able to fix it for $250-$300. Im not keen on the idea of a second hand one because it could be the same problem. I need to know what the reliability of it will be if I hand it over to an engineer

[DilboBaggins]

Ive been reading some other threads and some say you can drill two hole behind and through the balancer and put high tensile metal in the holes but the holes have to be smaller then the washer on the main bolt so that you dont have to replace the crank or keyway. Has anyone done this successfully? Cheers

[happygu]

Dilbo,

There are a few repair methods, and this will depend on the amount of damage sustained.

When I used to work in the family business, we used to repair keyways on the main shaft on giant brake presses which hold the massive flywheels ( of which there would be massively more strain on the keyways than a harmonic balancer, but the repair depended on the amount of damage, and we probably had less damage than yours ), and we would use different methods depending on the repair.....

Let a machinist ( fitter/ toolmaker ) take a look if you can, and they can advise.

The cheapest method would be something like JB Weld, but I wouldn't want to rely on this long term if I was going into the middle of nowhere....

Welding and re-grinding is long term, but you can run the risk of the heat distorting the shaft.

Re-slotting the keyway, or widening the keyway on the shaft and pulley can sometimes be an answer too.


I have heard of someone welding the harmonic balancer onto the shaft directly, and although this will work, it wouldn't be my preferred option, as you then make it unserviceable for main seal repairs and the like.

A bit of food for thought for you....

[DilboBaggins]

I have photos of the damage but cant seem to find out how to post them from my phone. Ill have a chat to a engineering joint and see what they can do. Would they be able to fix it whilst still in the engine? Or would it have to come out? Cheers mate

[Avo]

you'd think it would have to out because of the heat would stuff the seals I think mate.and trying to get in there and do a good job.

[happygu]

If Patrolapart have good second hand ones, it may work out to be a good option, as i would think the crank has to come out anyway if you choose to repair - depending on the level of repair required........

If you have to take the crankshaft out, you can pull apart with the engine block in chassis, but you have to separate the engine and transmission to remove the crank and check bearings for wear or damage, and this can be difficult in car.

It is much easier to assess and replace components on an engine stand......

[DilboBaggins]

Thanks for that guys, ill ring the engineering place tomorrow and see if one of them can come have a look or ill just send some pictures. The troll will have to go to a mechanic as I dont have the necessary tools unless anyone in perth wants to lend me a engine crane thanks again guys, ill post more info tomorrow