Ridiculously tight crankshaft pulley bolt (91Polo)

[Tim]

Hi all

Struggling like anything at the moment with a crankshaft pulley bolt on my 91 Polo (1.3 AAV Engine)

Breaker bar wont touch it

450nm 240V Impact Wrench won't touch it.


Plan for tonight is to attack it with a longer bar (read scaffold pole). Rest the socket extension on an axle stand to support it and stop/limit sideways force on and slip the pole over the breaker for extra leverage.

I'm half expecting the breaker/socket/extension to snap (it's only 1/2" drive), but worried about snapping the bolt head off! Which would probably mean new engine


How tight should these things be, and it IS RH thread isnt it (anti-clockwise to loosen).

I'm locking it in 5th with the brakes on hard - once the flex/play in the box is taken up it locks hard.


I need to undo it to replace the oil seal!


Cheers!

Tim

[waveman1500]

Crank pulley bolts are sometimes like that! Good luck mate. Penetrating oil, impact and leverage are all your friends.

[stealthstylz]

I had the same problem with mine - ended up getting a mate to jam a chisel in the flywheel ring gear to lock it. I then put about 2 feet of extension bars on the socket (going through the hole in the inner wing) so that the end was outside of the wing and rested it on an axle stand with a bit of box section tacked on top to stop it slipping. I then put a 4 foot breaker bar on it and a length of scaffold pole and it came off. They're crazy tight, but once cracked you can undo them with your fingers.

Matt

[sasquar]

There are two things that never fail to get very tight crankshaft bolts undone, one is safe the other less so.....

1. A big windy gun, obviously only works if you have a big windy gun, and a compressor.

2. A large breaker bar and a flick of the starter.... Obviously, make bloody sure the engine wont start (take the plugs out - lessens the compression, makes it easier for the starter to turn the engine) and be bloody careful where you put the end of the breaker bar....... Seriously, if you're not careful, this could go very very wrong, however, if you are, it makes them a very easy job.....

[Tim]

Sasquar - windy gun isn't available, and Option 2 has been outlined a couple of times, but i'm not brave enough to try it whilst there may be other options available :-)

Matt - thats the general idea, apart from i can't get anything to stay in the flywheel (tried a chisel - keeps slipping). Brakes seem to hold it though. Was a bit worried about something breaking and ending up inside the bell housing as well!

[ejenner]

I have had a crank pulley bolt which wouldn't losen with the starter motor method. Saab tractors are tough to work on sometimes.

Something else I would recommend trying is to leave the engine idling for 1/2 an hour until it is well and truely cooking.

Then try and open the crank pulley bolt.

Good luck.

These days I use method number 1 posted above. Works every time.

[Tim]

Can't run engine as it wont hold oil!

Plus, it's partially in bits :-)

[Dez]

VW crank nuts are pretty much all like that in my experience.

matts method is best imho, as its also my method! having someone else there holding a chisel in the flywheel teeth does make a big difference over holding it on the brakes.

[RobinJI]

Yeah, get something wedged in the flywheel, my Scirocco's one was a pain too, windy gun wouldn't do it, and locking it in gear the play in the box absorbed most of the force being put through it. Screwdriver in the flywheel teeth and a big breaker bar got it in the end.

[Tim]

Struggled to get a chisel/scredriver not to slip, but will persevere.

Cheers all

[stealthstylz]

Have you taken the starter off it's easiest to jam on in there?

[Tim]

Yeah starter off

[murran]

take the spark plug out of no.1 get the engine so its past the tdc marks on the crank and cam about half way down the no.1 power stroke... feed in some soft rope into the cylinder to lock the engine up as you undo the crank bolt..... or in the same engine position try filling the cyl with gear oil and refit the plug to hydraulic it in the same way (might make a mess when you spin the engine over with the plugs out to get the oil back out! then smoke abit on start up!).....
or bob the sump off and stick a chunk of wood in the crank somewhere.

[dave21478]

Breaker bar and starter motor - works a charm.

I was wary the first tie I tried this, but nothing would touch the bolt.... impact guns, breaker bars with scaffold poles etc.... the more leverage I tried, the riskier things became of either the tool slipping and hurting me, or breaking something important.

Just put the socket on a std breaker bar and place it firmly on the bolt, leaving a few inches between the bar and whatever is going to stop it, whether its the ground of the lower arm etc. Disconnect whatever is needed to prevent the engine firing, and give it a turn of the key....works perfectly.

[Adam]

Did the one on the MR2 the other week to replace the pulley / change cam belt. Air impact gun wouldnt do it, was about to try the starter method but managed to get it to go by locking the flywheel with a screwdriver and using a 3ft scaffold pole on the 1/2" breaker bar. It went with a bloody scary bang! This method was made much easier by the inspection pit.

[Tim]

I've got a 10ft scaffold pole sat in the carport, ready and waiting.

Just need to find someone to lock the brakes/flywheel for me :-)

[bortaf]

Is this the pully with the 4 allen head bolts that hold it to the cambelt totther wheel behind?
had these before and had to borrow a commercial nut gun to get the dam thing off !!
for locking the brakes i have a "special" tool (cut down broom) to wedge the pedal down against the front seat ;D

[stealthstylz]

Yeah 4 allen bolts for the pulley, usually at least one already half rounded off lol.

[MrSpeedy]

Jun 28, 2011 17:40:10 GMT murran said:

take the spark plug out of no.1 get the engine so its past the tdc marks on the crank and cam about half way down the no.1 power stroke... feed in some soft rope into the cylinder to lock the engine up as you undo the crank bolt..... or in the same engine position try filling the cyl with gear oil and refit the plug to hydraulic it in the same way (might make a mess when you spin the engine over with the plugs out to get the oil back out! then smoke abit on start up!).....
or bob the sump off and stick a chunk of wood in the crank somewhere.

I would strongly advise against jamming the top of the engine, either by rope or hydraulically, as you risk bending the conrods.

Blocking in the crankwebs is a much better idea

Is the gearbox off ? If so, you could quickly make a locking tool to engage in the ring gear teeth and bolt to the bell housing, then get a 3/4" drive socket and breaker bar. 1/2" is working against you as it'll just bend and spring thus reducing the amount of effort actually reaching the bolt !

To expand on your socket/axlestand method, try a good fitting 3/4" drive socket and T-Bar. Support with axle stand.
Take one good sharp swing with a sledgehammer at the bar.

I've shifted many large (2 1/2" AF and bigger) using this method

[Tim]

Haven't got a 3/4" bar or tools, and i really don't want to buy anything else.

But yes, that does make good sense.