450B diesel 207D removing front crankshaft retaining nut tips and tricks

[jasonmo450b]

I'm trying to fix a engine oil leak which appears to be coming from my timing cover above the injection pump. My rubber in the engine mounts deteriorated and let the front of the engine drop down and had both the hydraulic pump and alternator rubbing.... what has me held up now is the retaining nut with the square bore on the front crankshaft pulley. We tried a impact and also applied some heat and didn't budge it yet. Everything i read and everyone I have spoken to indicate is a standard rotation thread...
We are probably going to borrow a torque multiplier and/or bigger breaker bar. I appreciate any tips and tricks folks can send my way!!

 

[jasonmo450b]

 

[jasonmo450b]

 

[Delmer]

Bigger impact, or bigger/shorter hose, if you can't bring the compressor closer, then make a tank with a 3/4 hose about 3' long to a 3/4 or 1" impact for something like this. Filled with a small hose hooked up, and you get a second of power, then wait for it to stop whistling and it's ready to hit it again.

Alternate back and forth, some times it's easier to tighten a bolt a bit to break it loose, no idea why but it works.

 

[Dave Neubert]

Get a 3/4 impact it will take the nut off

 

[Coy Lancaster]

Hit the nut with a 4lb engineers hammer, block the engine form turning and use a 3/4" breaker bar. Some probably put loctite on nut at one time in the past. A good 3/4" air wrench will help also.

 

[kshansen]

I hesitate to use an impact for something like this as often the "nut" is a soft steel item and the square drive can strip out if it takes more that a short burst of the impact. If you do use the impact and it turns say 1/4 turn and is still turning hard it probably has be lock-tited.

If it is lock-tited, the "blue stuff"a bit of heat will work wonders, don't have to get red hot just something around 350-400ºF should do the trick. Even if someone went crazy and used red lock-tite 550ºF will let it turn pretty easy.

 

[jasonmo450b]

Thanks guys I have a multiplier borrowed I plan to try over the next couple days. We tried some heat last weekend but may have been too bashful with it.... Also got in touch with the last guy that had it apart but he couldn't remember details on the crank pulley.

 

[jasonmo450b]

OK, just got a chance to work on this again and succeeded by getting a MAC brand impact adapter 3/4" to 1/2" and borrowed a 3/4" drive breaker bar with "extension" added to handle......we snubbed the ring gear on flywheel and it popped free......turned rest of way off with just fingers.....now I need to strip it further down and hopefully will see where and why the timing cover is leaking engine oil.

 

[jasonmo450b]