M8 bolts crankshaft pulley removal - 200tdi

Hi all,

Need some wisdom on how best to remove the M8 bolts that hold on the front crankshaft pulley. I need this off so I can use the pulley holding tool to removal the M30 crankshaft bolt ... so I can do the timing belt replacement. They are very old that the heads are some what worn/rested. Will not budge with the small socket set due to the M10 socket size you need to use. Do I go hell for leather and use a impact driver with a M10 socket on it and see what breaks first. Or would using freezing spray help shrinking the bolts?

Any help and advice would be much appreciated.

Heat them up. Then use a 6 point socket and a long bar. Some penetrating fluid always helps. If heads rounded Irwin bolt removers are good.

I had a similar issue years ago, couldn't get an irwin on them so smashed a smaller socket on and that worked.
Replaced them with socket head bolts, stainless steel, still good 16 yrs later, had them off 3 times at least over that time, easy to do now.

Flossie said:

I had a similar issue years ago, couldn't get an irwin on them so smashed a smaller socket on and that worked.
Replaced them with socket head bolts, stainless steel, still good 16 yrs later, had them off 3 times at least over that time, easy to do now.

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Thanks for the heads up.... yep it’s so hard to get a socket onto these bolts.
For the replacement bolts was these Allen key key bolts you put back?

Has anyone managed to get a 1/2 M10 sockets on these bolts before? Used my small size M10 socket last night and the socket broke due to the force of trying to get it off.

AH-4x4 said:

Has anyone managed to get a 1/2 M10 sockets on these bolts before? Used my small size M10 socket last night and the socket broke due to the force of trying to get it off.

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Think I just used 3/8 drive 10mm sockets on mine, very important to only use single hex sockets, ie the 6 sided jobbies, avoid the 12 sided bi hex ones like the plaque.
Halfords sockets are pretty good for diy.

If you can borrow a battery gun they are excellent for the crank bolt itself.

As above, use penetrating fluid and soak [PlusGas is best]and then use heat [ideally MapGas] and gently crack the bolts. Try not to be too aggressive, you don't want a bolt to snap. Replace with A4-70/80 grade st/st bolts, thoroughly cleaning out thread and refit with copperslip or ceramic spray grease.

note: don't use Allen heads as they clog up with muck and there's less head to work with when undoing in the future.

I used a 10 mm impact socket with a bit of heat but still managed to snap one,
But once the pulley is off the broken one came out easily with heat and a vice grip/mole grip,
When the head sheared off it still left enough of the shank to undo,

AH-4x4 said:

Thanks for the heads up.... yep it’s so hard to get a socket onto these bolts.
For the replacement bolts was these Allen key key bolts you put back?

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Yes Allen head bolts.
As @v8250 says they can fill with mud
But mine don't as I don't really do sloppy deep mud stuff anymore but you just clean them out with a suitable instrument before going in all gung ho.
You can get little plastic caps to fit into them but it isn't necessary.
I would be reluctant to use heat, the damper behind has bonded rubber in its construction.

@Flossie, good point re damper rubber

@AH-4x4, inspect the damper vulcanised rubber when damper off. If old/brittle buy a new damper, they're not expensive and cause untold damage when they let go

So an update.... Good news bad news. 1 out of 4 bolts came off, the other three their heads are rounded off now. Can't get Irwin socket in there to try and undo it. Wish I never started now.
Any ideas guys on how to get these three bolts out in this very tight space?

Drill the heads off maybe?
Drop the sump and lock the crank with timber so you can undo the M30 bolt and remove the thing complete with the damper so you can work on it on a bench etc.?
Cut the pulley away until there is nowt left so you can get an irwin on it?
Don't know how much another pulley would cost.

Or weld something substantial to the pulley that will act as a locking tool so you can undo the M30 bolt?

Easier to undo the pulley bolt with the starter or an impact if you can fit it in there, and avoid all this trouble

Whatever you do them bolts will almost certainly have to come out as the damper will need a puller to remove, dont use a bar as you might break the timing case cover.
Why wont the irwins fit?
What is the engine in? I ask as def 200 has loads of room at the front, even more if you remove rad/intercooler package.

Kev12 said:

Easier to undo the pulley bolt with the starter or an impact if you can fit it in there, and avoid all this trouble

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Of course, forgot about the starter method

lynall said:

Whatever you do them bolts will almost certainly have to come out as the damper will need a puller to remove, dont use a bar as you might break the timing case cover.
Why wont the irwins fit?
What is the engine in? I ask as def 200 has loads of room at the front, even more if you remove rad/intercooler package.

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Irwin socket is too fat when I tried it, 1/2" drive mine are, do they do smaller/slimmer?
My damper comes off by hand but I know not all will.

Hi guys,

The engine is out of the defender the Irwin socket is just to wide to get it on the bolt.

To drill out the bolt heads any tricks of the trade out there? Any special drill bits to use? Not looking forward to it

AH-4x4 said:

Hi guys,

The engine is out of the defender the Irwin socket is just to wide to get it on the bolt.

To drill out the bolt heads any tricks of the trade out there? Any special drill bits to use? Not looking forward to it

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I'd be tempted to remove the sump and lock the crank that way, remove bolt and remove pulley and damper complete. Any small engineering place will get them out cheaply I guess.

Flossie said:

Irwin socket is too fat when I tried it, 1/2" drive mine are, do they do smaller/slimmer?
My damper comes off by hand but I know not all will.

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Mine are snap on, which are just rebranded irwins (I of cousre did not know that at the time!) but they are 3/8 drive, great bits of kit, get me out of trouble all the time.
I always grease my damper, yet still it needs the puller, no effort needed just seems to have to come off dead square.