Thread: 1996 Deisel - Broken crank shaft

if youve cooked a head or been running dodgy oil then yes you can cause fatigue damage to the crank, all it takes is a hairline crack in the bearing surfaces (or a main journal loose or a big end loose) of the crank and every time a torque impulse is put through the crack widens, very very slowly at first and the more quickly untill there is more crack than crank and then snappo, done crank.

IMHO the most common cause of crank failure in the TDiX00 is lack of Preventative maintenace with regards to the harmonic balancer.

If the timing has gone advanced then the diesel knock is very destructive and could result in a snapped crank but there would be plenty of other damage as well.

If the engine had "hydro-locked" to a stop as part of the head going or for any other reason the crank had run out of true thats also a fairly major contributing factor.

The other common cause of crank failures in ANY diesel engine is incorrectly machined radii at the journal ends where they meet the counterweight. Unlikely to be a problem in a 1996 build IME, but if you had said your disco was a 1998/9 then I would've agreed it was a fatigue induced poor machining issue as I have seen 4 now in that age group fail. None of these cranks had been touched since the vehicle was manufactured.

Possibly if the timing was extremely advanced and the detonation knock was a LOT noisier than what you have experienced prior to the belt being changed, then that could hasten its demise, and also the timing can be out enough on the camshaft to cause the valves to kiss the pistons, that increases engine noise, harshness and leads to a lack of power.

After the crank broke, what was the procedure for autopsy? Has anyone been able to do a thourough post destruction examination yet?

JC

As to repairs -

If your other half can do the spanner work - then a replacement engine is not that expensive. Nor is it that hard - if you have a workshop manual.

Parkridge auto wreckers (Loganlea) had a 300tdi Disco in their yard not too long ago - and they are do-it-yourself wreckers so they don't charge like wounded bulls.

Having been through crankshaft replacement ( damaged nose of crank), I can say that doing it engine out of the vehicle is the way to go. If you have the space to do that - the rest is easy.

and once youve found the engine Ive got the gear to whip and engine in and out if you need it..

You can buy a stroker kit (2.8) with new crank, rods, pistons, rings and bearings for around $2800, all you would need is a bore job to suit and you're in business again, Regards Frank.

Originally Posted by Kerry11

.............. Hubby argues that we've had the head, timing belt, hoses, ABS sensors replaced so we should keep it. But I wonder if it will be the clutch to go next....etc....etc. The car just isn't worth as much as we spend on it. Even though it really is in goo nick.
........

Kerry

the usual thing will be to replace the clutch before installing the repaired/replacement engine - so that's one saving already

Originally Posted by Kerry11

Hubby argues that we've had the head, timing belt, hoses, ABS sensors replaced so we should keep it. But I wonder if it will be the clutch to go next....etc....etc. The car just isn't worth as much as we spend on it. Even though it really is in goo nick.

Kerry

ROFL....

didnt even read that bit properly the first time, allow me to put that in perspective for you...

One of my vehicles if I was ever to pay for a full tyre replacement with balancing (hell even if I only bought the minimum 4 and bought decent rubber) Id be spending more on it than I paid for it. Filling it From empty at discount fuel priced servos would cost more than half what I paid for it. Yet Im about to pull it down to the chassis, galv that, graft on more tanks, winches, rebuild the engine, gearbox, diffs, suspesnion, rewire it, add an air compressor and maybe even fix the cab leaks.

Ok I probably wont go and fix the cab leaks, I'd have to buy new door tops for it and lets face it, its not worth that much.

Thanks everyone for your replies. I feel like I'm trying to read French though. I have no clue as to what most of that meant...but I will show hubby and he can try to decipher it for me.

I'm not sure if he can do that sort of work on the car himself, but he has a mate who might be able to help him........but that's a big maybe.

So, I've read all the responses through a couple of times and I'm sorry to admit that I still don't understand, but as I said I will get hubby to read it through.

Do you think it had anything to do with getting the timing belt replaced? There was no problem with the car before the replacement, we just did it as a matter of regular maintenance. I'm a bit annoyed with the mechanic because he kept the car from early Monday morning and was still working on it when we went to pick it up at midday the following Saturday. I was worried that he did a rush job at the last minute and made some mistakes. He was test driving it at 1pm while we waited. Within 48 hours, and far from home, we felt that things were not right but couldn't quite think what it could be.

Originally Posted by justinc

T

After the crank broke, what was the procedure for autopsy? Has anyone been able to do a thourough post destruction examination yet?

JC

Same mechanic as mentioned above has had the car for a full 7 working days before even looking at it. He rang today to say the crankshaft is broken, but he's still not sure what other damage there might be. I'm not quite sure what to expect in terms of damage and $$.

I really appreciate all your advice so far.