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opethmike
11-27-2017, 04:12 PM
I am presently parting out my old PRV as I am putting an LS into my car. I've dealt with some pretty stuck on crank pulley nuts on all sorts of cars, including DeLoreans, but nothing so diabolical as this.

My 1,200 lb/ft impact wrench won't budge it. I bent a six foot breaker bar cranking on it. I've tried both said impact and breaker bar after MAP gas torching the nut for several minutes, but still to no avail.

Any suggestions for getting this thing off of here?
Josh
11-27-2017, 04:21 PM
longer breaker bar!
opethmike
11-27-2017, 04:42 PM
...that's what she said?
jangell
11-27-2017, 05:22 PM
longer breaker bar!

I wedged a screwdriver into the flywheel to keep the engine from rotating while I used a 6' pipe on the end of my wrench to force off the main pulley nut. I actually bent my flywheel before I got the nut off. Just a warning about using a bigger breaker bar.

I did not try heat at first, because I thought I'd damage the gaskets or something because I forgot how good of a heat sink the metal would be. I tediously cut off the nut with a Dremel and a series of cutting discs, finally got bored, hit it with a MAP torch, at which pint it spun right off. I did put some cuts on the threads of the shaft, but nothing that compromises how well a new nut holds the pulley in place. But opethmike already tried heat, so I'm not sure what to suggest. I'd leave cutting as a last resort.


On an unrelated note (and not to sidetrack the thread), I'm probably going to be bothering both of you in the coming weeks about EFI conversions, as I finally plan to turn the key on my 3.0L PRV/Megasquirt/EDIS conversion on Saturday. I think I have everything set up properly... I'll start a thread once I start having problems. :)

-- Joe
dn010
11-27-2017, 08:12 PM
Try to hit it with more heat, longer duration.


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David T
11-27-2017, 08:13 PM
A big part of getting that nut loose is to hold the crankshaft VERY solidly. if you don't have the special tool that locks the flywheel with a section of teeth you need to make one. Then the shock of an impact wrench will not get absorbed by something holding the flywheel and flexing. A longer breaker bar doesn't apply the shock necessary to break that nut loose.
Josh
11-27-2017, 10:43 PM
On an unrelated note (and not to sidetrack the thread), I'm probably going to be bothering both of you in the coming weeks about EFI conversions, as I finally plan to turn the key on my 3.0L PRV/Megasquirt/EDIS conversion on Saturday. I think I have everything set up properly... I'll start a thread once I start having problems. :)

-- Joe

I look forward to it!
vwdmc16
11-27-2017, 11:29 PM
I also had lots of issues with my pulley nut. 3/4" drive vreaker bar with 5ft extention. Also used a mapp gas torch. It was a full hour ordeal.
sdg3205
11-28-2017, 01:59 AM
The key is to only ever torque it finger tight to begin with.
PJ Grady Inc.
11-28-2017, 04:01 PM
The key is to only ever torque it finger tight to begin with.

Correct the manual says torque to finger tight....then "Torque to 135# with Loctite"!
Rob
sdg3205
11-28-2017, 04:48 PM
Lol. I'm glad no one thought I was serious.
PJ Grady Inc.
11-28-2017, 05:02 PM
Lol. I'm glad no one thought I was serious.

You just never know!!!!
Flash66
11-28-2017, 07:49 PM
Had a similar issue. Just stay on that nut with your impact for as long as it takes. It'll finally break free. Took me 30 minutes or so on and off with the impact. Be persistent!

Really no need to brace the flywheel using the impact. Just when I was about to give up, BZzzzzzzz it came off!
PJ Grady Inc.
11-28-2017, 09:01 PM
Had a similar issue. Just stay on that nut with your impact for as long as it takes. It'll finally break free. Took me 30 minutes or so on and off with the impact. Be persistent!

Really no need to brace the flywheel using the impact. Just when I was about to give up, BZzzzzzzz it came off!
Impact gun, torch heat, and patience will crack the most stubborn of nuts at "the end of the day"!
Flash66
11-28-2017, 09:04 PM
Impact gun, torch heat, and patience will crack the most stubborn of nuts at "the end of the day"!

Right on! Btw turn your compressor PSI as high as the regulator will go. 90psi will not get the job done. Set mine at 150psi and buzzed that bitch off. As Rob said, Patience is the key.
opethmike
12-04-2017, 04:06 PM
5 minutes straight of MAPP blow torch, 150 PSI on the compressor aaaaaaand - nothing.
5 more minutes of torching, breaker bar with 12 (!!!) foot pipe aaaaaand - nothing.

WTF now, lol?
eight8toy
12-04-2017, 05:30 PM
I swore a lot at mine, that helped. Also did you soak it with PB Blaster? I remember using the heat so long the back of the pulley started smoking. Took me several days of frustrated attempts before mine finally gave way with impact gun, keep at it!
sdg3205
12-04-2017, 05:57 PM
Did you use thread locker Mike?
dn010
12-04-2017, 06:00 PM
You can drill some holes in the nut to get some PB at the threads but you risk damaging crank threads. Same with cutting it off with a cut off tool/discs.


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Bitsyncmaster
12-04-2017, 07:11 PM
Do you know someone with and oxygen/acetylene torch? The higher heat can get the nut heated faster without heating the crank that much.
David T
12-04-2017, 08:23 PM
Do you know someone with and oxygen/acetylene torch? The higher heat can get the nut heated faster without heating the crank that much.

I agree you will get a lot more heat with an acetylene torch and an impact gun has a lot more shock than a breaker bar. You can try hitting the long pipe and breaker bar with a hand sledge but it isn't as good as an impact gun.
nullset
12-05-2017, 12:09 AM
5 minutes straight of MAPP blow torch, 150 PSI on the compressor aaaaaaand - nothing.
5 more minutes of torching, breaker bar with 12 (!!!) foot pipe aaaaaand - nothing.

WTF now, lol?

What's the rating on your impact gun?
opethmike
12-05-2017, 01:15 AM
What's the rating on your impact gun?

1,200 lb/ft
DMC-81
12-05-2017, 02:38 AM
5 minutes straight of MAPP blow torch, 150 PSI on the compressor aaaaaaand - nothing.
5 more minutes of torching, breaker bar with 12 (!!!) foot pipe aaaaaand - nothing.

WTF now, lol?

You might as well try this:

-Heat the nut a bit, only the nut, not the shaft.
-Melt some candle wax into the threads. With the nut hot, the wax should be drawn into the threads
-spray some WD-40 or equivalent on the shaft
-Hit it with the impact wrench.
-Repeat if necessary

The idea is to lubricate to threads with the the wax and create a temperature differential with a hot nut and a cooler shaft so that the nut expands slightly on the shaft. I did this successfully on my rusty exhaust hardware.

I modified the procedure from this source: https://www.youtube.com/watch?v=KFdFsfSAuyc

Good luck.