How to lock a crankshaft.

[Bellow]

As per title. I have to remove the bolt on the crank's nose and need to secure the crank against turning. Normally, put it in gear - but it's an auto.
Does anyone have a demon method for holding the crank? Is holding it at the ring gear (after starter motor removal) the only possibility? And, if so, what do you use to lock the crank? (Not sure just jamming it with a screwdriver will work for me as I'm working alone).
Any ideas, tips?
TIA.

 

[amazighman]

You can put a pry bar again the flexplate (flywheelf for autos) teeth .
There is usually a hole somewhere around bell housing to insert a locking pin or similar.
Alternatively you can try this from Halfords..
Laser Flywheel Holding Tool

 

[IanW]

The flywheel locking tools generally require that the gear box has been removed.
What the OP requires is the 'Crankshaft Harmonic Balancer Holding Tool'. This locks the crankshaft pulley while providing access to the bolt.
I've used homemade versions on the Audi 90 with great success - the crankshaft pulley requires removal to change the timing belt.

If you do use one of these tools, I'd be interested to know how you got on. The harmonic balancer on mine is starting to show signs of wear, and will need replacement in the next year or so.

Ian.

 

[Bellow]

Use of a locking tool further complicated by starter having bolts at 90 degrees to usual.

Impact wrench is the answer it seems - then crank doesn't need locking.
I've ordered a cheap (£25) 240V one viewing this as a one-off job and whatever it does after that as a bonus.

 

[amazighman]

A powerful impact should shift it...

 

[Bellow]

A powerful impact should shift it...

I found a YouTube vid of a guy doing the same job. Impact wrench rattled the bolt out in seconds without the crank moving at all.
The once I have used an impact wrench was to remove the steering wheel centre nut/bolt on my W123. Nothing else shifted it until the impact wrench rattled it free. They have their uses. Be interesting to see how the cheap and cheerful electric one works. For now, it only has to remove the bolt and then re-torque it.
ToeKnee (via PMs) has been helping me with other aspects of the job. He knows these engines better than anyone else I know - and it's not even an MB.

 

[Deleted member 126969]

I’ll second the rattle gun solution. Often relied on drilling the crank nut on an Alfa V6 engine to get them off, but last time, on recommendation, I got a MachineMart mains impact and it made very short work of it, no lock required. Found many more uses for it too of course.

 

[Bellow]

I’ll second the rattle gun solution. Often relied on drilling the crank nut on an Alfa V6 engine to get them off, but last time, on recommendation, I got a MachineMart mains impact and it made very short work of it, no lock required.Found many more uses for it too of course.

You're not joking!
Made it look as if the bolts had never been tightened.
I don't intend using it for everything - I've always preferred hand tools - but as back up, for £25, hard to regret that purchase.

 

[ToeKnee]

Glad that job has been done. Good luck with the removal now!

 

[Bellow]

Glad that job has been done. Good luck with the removal now!

Guessing that was the easy bit!
Just away to re-space the holes on a Mini flywheel puller and hopefully get the balancer off soon. More of a concern is if the 2'' long 7/16'' set screw for a refit tool is going to be long enough. From the photo of the removal tool you posted, I counted the threads and knowing the TPI count deduced 2''. Soon find out I guess.

 

[ToeKnee]

Two inches will be tight, if you think how thick the balancer is the bolt needs to be at least that thick, plus enough to screw into the crank plus enough to get a washer on and a big nut to wind it in. I've never measured it but I'd have thought at least 3"? Talking of washers, you'll need a pretty thick one at least bigger than the crank nose diameter/damper hole.

 

[Bellow]

Two inches will be tight, if you think how thick the balancer is the bolt needs to be at least that thick, plus enough to screw into the crank plus enough to get a washer on and a big nut to wind it in. I've never measured it but I'd have thought at least 3"? Talking of washers, you'll need a pretty thick one at least bigger than the crank nose diameter/damper hole.

Getting a 7/16'' bolt longer than 2'' was a struggle. I opted to try the 2'' one as available on short time scale (arrived today). I only got the pulley off today so haven't properly seen the thickness of the balancer. Or deduced completely refitting but I had in mind (loosely) to use my puller as a washer given its central bolt is large enough (OD) to allow the puller to easily fit over 7/16'' and use 7/16'' washers to bridge the hole (so to speak).
Off to modify the pullers - simple re-drill of three holes. Stroke of luck that the Mini puller has its three bolts the same thread as the L31's pulley three.

 

[ToeKnee]

Thinking about the tool link I sent you, only the very end of the tool is 7/16unf, the rest is a lot thicker to give better purchase when fitting the damper, hopefully you didn't calculate the length required by measuring the tpi on the thicker part?

 

[ToeKnee]

Also, you can buy 7/16unf studding in various lengths to make a tool rather than use a bolt.

 

[Bellow]

Thinking about the tool link I sent you, only the very end of the tool is 7/16unf, the rest is a lot thicker to give better purchase when fitting the damper, hopefully you didn't calculate the length required by measuring the tpi on the thicker part?

I though I noticed it was different over its length. I used the whole length to calculate 2''.
Once I have gauged how 'tight' it is during removal, I'll have a better idea of what to expect for refitting. Your point about studding is noted.

 

[Bellow]

Also, you can buy 7/16unf studding in various lengths to make a tool rather than use a bolt.

Long bolts are easily obtained. Set screws (ie threaded entire length) longer than 2'' are harder to find. I went with the set screw as its head would be useful without having to lock two nuts together.

 

[MissyD]

Reported

 

[Bellow]

The harmonic balancer is now removed. Not too bad once it started moving. Timing cover all but removed - stuck to the protruding sump so tomorrow (weather permitting) I'll go underneath the critter and see the extent to which the sump has to be removed. Next on the list is sorting out bolt/set screw length for re-fitting the balancer. Some progress then. And on removing the balancer - I was rewarded with a view of a timing cover split down the middle.

 

[Bellow]

It's in bits - so thinking about putting it back together. Sump gasket is ripped so organising a new one. Do I need gaskets for the water pump - or sealant (eg, Dirko)?

Still a bit confused re refitting balancer. Once it was moving (during removal) it wasn't too tough to remove and that was with everything stone cold (outside). I'm guessing refitting will be helped by the crank being just as cold but the balancer being quite warm (CH radiator warm). Heynes manual refers to using the retaining bolt to refit it but if it's tight to go on, I'd rather not stress the crank threads by winding on them. Looking at the puller I used, its bolt was only protruding 22mm when the balancer freed from the crank. The puller was bolted flush with balancer and I used a set screw to have its head on the same plane. By my reckoning, the balancer only 'grips' the crank over a length of 22mm. At that, I can just about get away with my 2'' long setscrew - plausible?

 

[ToeKnee]

I've tried various different ways to get the balancer on and the correct tool is the way to go although I have known of people having good success with threaded bar, large washers and winding it on with nuts as we've previously discussed. Personally I wouldn't use the crank threads to wind on because if they get damaged then you might not be able to get the crank bolt in and although it seems superfluous it is important to have that bolt there.