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Crank bolt problem


Les Henson

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I've been trying to remove the 42mm head crank bolt on a 2.5 N/A diesel for about a week now with no luck.

I have tried:-

Socket and breaker bar under off side chassis rail, flick the starter - it just makes a whining noise, but the bolt isn't having it. Put a fully recharged heavy duty battery on with no luck either. Wired 2 batteries together to make 24 volts and it still didn't budge.

The starter is a relatively new item, so I know it's ok.

I put a piece of angle iron in the flywheel teeth and tried leverage with a length of scaffold tube on the breaker bar, nothing doing. The flywheel took a chunk out of the angle iron.

I got hold of the correct locking tool today and broke it!

There's no way that I can think of of undoing the bolt and I have to remove the timing cover to inspect the timing belt and possibly replace the injector pump.

I have always used the breaker bar or flywheel lock with angle iron, and have always been successful, but I really can't think what else to try.

Apart from fitting a V8, or replacing the engine, does anyone have any ideas what else might work?

Les (in desperation) :(

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if you have tryed every thing else , i would remove rad, and drill it out , and replace with new bolt ,

would only have to remove the head and i think it will probably wind out for you , bits and bobs like bolts arent thet dear from landrover either , good luck :)

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are you turning in correct direction?

Damn! I knew there was something I was doing wrong :D

Not too keen on drilling the head off, the presence of locktite or whatever might make removal of the remains equally difficult. It would have to be a big drill bit too. Not sure what the diameter of the bolt shaft would be, about 18mm or thereabouts?

Les.

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Damn! I knew there was something I was doing wrong :D - Guessed you might have sussed that one :rolleyes:

Not too keen on drilling the head off, the presence of locktite or whatever might make removal of the remains equally difficult. It would have to be a big drill bit too. Not sure what the diameter of the bolt shaft would be, about 18mm or thereabouts?

Les.

Is there room to mig weld a chunky bar to the head? often the heat from welding will help and with a chunky lump of steel on there, easier to undo. Only problem Les is that you only have gas welding available? :D

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And, being you, I suppose you leave a gap between the breaker bar and chassis before you flick the starter? So the starter can gain a wee bit of momentum before it goes bang? Yeah, silly me... :rolleyes::)

Making sure that the breaker bar is not flexing? If you come over, you can borrow my spanner with a 2" wide handle. :)

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First time I took it off my old 300tdi, I too tried all the above.

What finally fixed it was my torque wrench (much less bendy than a breaker bar), sleeved in a bit of tube to protect it and letting it swing from the steering box to the chassis on the starter. I think the extra shock was enough to break the loctite. If you are really lucky, the engine might fire at the right moment to give it an even bigger kick.

Si

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Soak readily in a diesel/parrafin mix for a while, give it a good going over on the end with an airchissel and then get it glowing and try the starter?

Or

Hack the front of the engine off with a stihl saw :ph34r:

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Thanks for some of your suggestions (and comical replies from a predictable few <_< ) I don't have the heavy gear some of you suggest. The vehicle is out on the road, so I'm a bit limited as to what I can do. I can wheel out the small oxy gear and apply plenty of heat, so will try the heat/shock load method.

Les.

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Thanks for some of your suggestions (and comical replies from a predictable few <_< ) I don't have the heavy gear some of you suggest. The vehicle is out on the road, so I'm a bit limited as to what I can do. I can wheel out the small oxy gear and apply plenty of heat, so will try the heat/shock load method.

Les.

Even though I have a really heavy duty 3/4" air gun, sometimes these bolts just plain refuse to be undone.

For these very special occasions I use a sligtly different setup from the other methods described. You will need to positively lock the engine from moving. This can be done by bolting a suitable piece of steel to the crank damper - this way the engine i positively locked, and you can still access the bolt.

The pulleys can be unbolted from the crank damper. Then find a suitable lenght of flat steel (10mm thickness will do). Drill two holes using the unbolted pulley to measure from. Then grind the flat bar between the newly drilled holes, so the flat bar can be bolted to the damper pulley. Then - using a piece of strong chain - tie the other end of the flat bar to the chassis rail.

Then find a suitable socket and a 3/4" breaker bar and two meter pipe, whereafter the problem can be easy overcome using brute force! If the long pipe is impractical, just use a shorter pipe, but place a jack under and slowly lift.

Never seen a bolt which wouldnt come undone using above method.

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If the starter is struggling, it might be worth removing the injectors as well as giving the bar a bit of a run up to the chassis.

If there is thread lock on the bolt, some heat should sort it out, just don't go mad ;)

CAn't think of anything else that hasn't already been suggested.

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I have found that a windy gun works best. Last time on the V8, i was hanging off a 3ft bar (100kg of pure fat :rolleyes: ), but the windy gun got it off no probs (didnt even need to block the flywheel as its the little shocks that free the bolt.

A bit of heat would not hurt either, that usually the magic ingredient.

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