BMW 320cD (E46) - Can't loosen crankshaft pulley bolt

sleepysniper

Hi folks,

Crankshaft pulley on my car, E46 320CD (M47n engine), needs replacing. However, I am having an issue loosening the crankshaft pulley bolt. I've read about multiple methods online about doing this but none of the methods I tried seem to work for me. So far I have tried:

-car in gear, brakes applied, then turning the bolt anti-clockwise with a breaker bar + cheater bar. This doesn't work as the crank still turns (I'm assuming due to slack between the engine/transmission). Also heated the bolt and tried the above, same result.

-got a manual impact wrench (my battery powered impact wrench doesn't have near enough grunt for this) and tried hitting it several times on multiple occasions with a lump hammer, also tried it with heat - no movement

-tried heating the bolt and cooling it immediately with a freezing/cooling spray then hitting it with the manual impact wrench and lump hammer combo - still no movement

I am aware of the jamming a screwdriver or similar into the flywheel to lock the crank and then jumping on the breaker bar method but I am a bit hesitant to try this as I can envision either a flywheel tooth breaking or the screwdriver tip breaking and disappearing into the depths of the bellhousing.

I am also aware that BMW sell a special tool for locking the crank but don't want to shell out for this item that I will only use the once. Even then I am not entirely convinced it will work. The teeth for holding the tool don't seem the most robust - I accidentally hit one of the teeth when attempting to tap the bolt with the lump hammer and it snapped off. I have also seen instances of the tool ripping these holding teeth off, so I'm doubtful they will withstand ~400Nm of turning force.

Any other suggestions? Can some one at least confirm it is a standard right handed thread on these bolts and loosens by turning anti-clockwise? I have read conflicting information online regarding this, some engines seem to be standard thread others are reverse threaded. I get its a really really tight bolt (approx. 400Nm tightening torque) but I'm getting no movement whatsoever on this bolt and I am wondering if I am even trying to loosen it in the correct direction?

Whocare

sleepysniper wrote: »

Hi folks,

Crankshaft pulley on my car, E46 320CD (M47n engine), needs replacing. However, I am having an issue loosening the crankshaft pulley bolt. I've read about multiple methods online about doing this but none of the methods I tried seem to work for me. So far I have tried:

-car in gear, brakes applied, then turning the bolt anti-clockwise with a breaker bar + cheater bar. This doesn't work as the crank still turns (I'm assuming due to slack between the engine/transmission). Also heated the bolt and tried the above, same result.

-got a manual impact wrench (my battery powered impact wrench doesn't have near enough grunt for this) and tried hitting it several times on multiple occasions with a lump hammer, also tried it with heat - no movement

-tried heating the bolt and cooling it immediately with a freezing/cooling spray then hitting it with the manual impact wrench and lump hammer combo - still no movement

I am aware of the jamming a screwdriver or similar into the flywheel to lock the crank and then jumping on the breaker bar method but I am a bit hesitant to try this as I can envision either a flywheel tooth breaking or the screwdriver tip breaking and disappearing into the depths of the bellhousing.

I am also aware that BMW sell a special tool for locking the crank but don't want to shell out for this item that I will only use the once. Even then I am not entirely convinced it will work. The teeth for holding the tool don't seem the most robust - I accidentally hit one of the teeth when attempting to tap the bolt with the lump hammer and it snapped off. I have also seen instances of the tool ripping these holding teeth off, so I'm doubtful they will withstand ~400Nm of turning force.

Any other suggestions? Can some one at least confirm it is a standard right handed thread on these bolts and loosens by turning anti-clockwise? I have read conflicting information online regarding this, some engines seem to be standard thread others are reverse threaded. I get its a really really tight bolt (approx. 400Nm tightening torque) but I'm getting no movement whatsoever on this bolt and I am wondering if I am even trying to loosen it in the correct direction?

Change one only last year on 320cd 2005 my method was a braker bar and socket and use starter motor to loosen it

Whocare

sleepysniper wrote: »

Hi folks,

Crankshaft pulley on my car, E46 320CD (M47n engine), needs replacing. However, I am having an issue loosening the crankshaft pulley bolt. I've read about multiple methods online about doing this but none of the methods I tried seem to work for me. So far I have tried:

-car in gear, brakes applied, then turning the bolt anti-clockwise with a breaker bar + cheater bar. This doesn't work as the crank still turns (I'm assuming due to slack between the engine/transmission). Also heated the bolt and tried the above, same result.

-got a manual impact wrench (my battery powered impact wrench doesn't have near enough grunt for this) and tried hitting it several times on multiple occasions with a lump hammer, also tried it with heat - no movement

-tried heating the bolt and cooling it immediately with a freezing/cooling spray then hitting it with the manual impact wrench and lump hammer combo - still no movement

I am aware of the jamming a screwdriver or similar into the flywheel to lock the crank and then jumping on the breaker bar method but I am a bit hesitant to try this as I can envision either a flywheel tooth breaking or the screwdriver tip breaking and disappearing into the depths of the bellhousing.

I am also aware that BMW sell a special tool for locking the crank but don't want to shell out for this item that I will only use the once. Even then I am not entirely convinced it will work. The teeth for holding the tool don't seem the most robust - I accidentally hit one of the teeth when attempting to tap the bolt with the lump hammer and it snapped off. I have also seen instances of the tool ripping these holding teeth off, so I'm doubtful they will withstand ~400Nm of turning force.

Any other suggestions? Can some one at least confirm it is a standard right handed thread on these bolts and loosens by turning anti-clockwise? I have read conflicting information online regarding this, some engines seem to be standard thread others are reverse threaded. I get its a really really tight bolt (approx. 400Nm tightening torque) but I'm getting no movement whatsoever on this bolt and I am wondering if I am even trying to loosen it in the correct direction?

It definitely anti-clockwise to loosen it well it was on my car anyway 320cd 2005

sleepysniper

Whocare wrote: »

It definitely anti-clockwise to loosen it well it was on my car anyway 320cd 2005

Thanks for the info, I tried the starter method but didn't work. I ended up locking the flywheel teeth with a chisel and managed to break it loose using a 3/4" socket drive, a cheater bar and a lot of effort!