w124 crank bolt removal

[imbck666]

Hi all,

Just a quick one really..

Dropped a bit of plastic through the gap where the duplex chain is in the timing chain cover and now i cant hand crank the engine... The plastic has siezed it, so need the timing chain cover off asap.

To take it off I am aware that I need to take harmonic balancer etc off but I need that fat crank bolt off first..

Now the question is, can I take it off with a long breaker bar or do I need an impact wrench? Do I need to heat it up?

The factory manual says its torqued on to 300nm (220 ftlbs)!

Any help would be appriciated

 

[carat 3.6]

You need to use an impact gun normaly, it is very hard to stop the engine turning when you use the breaker bar. If it's like the m103 it will be tight!

 

[Dieselman]

Lock the crank at the flywheel, put a well fitting socket on the bolt, fit a breaker bar and use a pole to whack the bar down to shock the bolt free.

 

[imbck666]

would I need to heat it first?

 

[imbck666]

And is it reverse thread or just anti-clockwise like opening a normal nut?

 

[Dieselman]

Normal thread, don't heat it.

With the flywheel well locked you might undo it anyway, I can do about 250 lb/ft with my foot blocking a bar to stop a hub turning.

 

[grober]

Steel scaffold pole slipped over the breaker bar if you can "borrow" one.

 

[sagesingh]

Steel scaffold pole slipped over the breaker bar if you can "borrow" one.

if you cant find a scaffold bar, try the bar on the jack, mine is just large enough to fit over the breaker bar to extend it that little bit further.

 

[Will]

Impact gun (air or cordless) would be much easier!

 

[kth286]

Impact gun (air or cordless) would be much easier!

Is there space with Radiator in situ on 4 cylinder ?


I replaced my crank oil seal on 95 320 6 cylinder coupe with Rad in place and used a length of tube over the braker bar, and it worked well.

Space is very limited, but made aluminium sheet cover to protect Rad fins.

Fortunately I had a torque wrench that allowed proper tightening of crank bolt and had a locking device for flywheel.

 

[Will]

Is there space with Radiator in situ on 4 cylinder ?


I replaced my crank oil seal on 95 320 6 cylinder coupe with Rad in place and used a length of tube over the braker bar, and it worked well.

Space is very limited, but made aluminium sheet cover to protect Rad fins.

Fortunately I had a torque wrench that allowed proper tightening of crank bolt and had a locking device for flywheel.

You'd definitely have to remove the radiator at least, but that's only a five-ten minute job and as the OP has the car stripped for a CHG replacement I guess it's already out.

The modern cordless impact guns are amazing, I've had one of these for a while now and haven't come across anything it won't spin off:

CTU6850, Impact Wrench, Cordless, 18 Volt, Slide-on Battery, 1/2" Drive (United Kingdom)

620ft lb of breakaway torque, so a 220ft lb crank nut should be quite easy

Will

 

[Will]

Duplicate.

 

[panason1c]

I have the same snap-on impact gun (as above), amazing bit of kit, highly recommended.

 

[BlackC55]

I have both an air and battery impact gun from Snap-on. Both on 1/2" drive and both the best they do. Neither will normally touch a crank pully bolt. Use a breaker bar. It works everytime.

 

[imbck666]

Hi,
purchased an impact wrench (cordless) with 450lb breakaway torque and tried for ages to get the nut off but it wont budge..
Full charge 5 cycles on battery to get it up to performance and the wrench just wouldn't get the nut off!
What do I do? Help

 

[carat 3.6]

Where in london are you?

 

[imbck666]

SE london (Southwark) SE1

 

[carat 3.6]

If I can find it, I have a "crank breaker" tool around here somewhere, that might help you out.

 

[imbck666]

Wow, I would really appreciate that!

 

[carat 3.6]

Send me a pm with your address and phone number, and I'll see what I can do.