The impact wrench is acceptable for removing that bolt.

Thank you for your response. I tried the Impact wrench.

Crank bolt wont budge using impact wrench at full power - 390 ft lbs!

Could it be left handed thread?

Factory manual plus 2 aftermkt manuals have no mention of left handed thread.

None of local Toyota dealers have bolt in stock - 3 day order item - which would resolve left-handed thread

question. Bolt was out in 2000 when timing belt was changed by Toyota dealer.

If some misguided person put thread-locker on bolt, any suggestions for removal?

I have propane & acetylene torches. Suggestions for amount & technique?

Thanks for your help!

You have a weak impact wrench or not enough air. When was the last time the impact was oiled ? A good wrench with proper air should snap off a 1/2 inch bolt clamped in a vice.

The bolt is not left handed thread, it is a normal "lefty-loosey". VBG.

It's likely that it has corroded to the pulley, and of course could have started this last job on the tight side. A stronger impact gun would pull it (or possibly break it, but not likely) The worst case scenario includes crankshaft thread damage that is binding the bolt to the crankshaft. I do not advise heating this, because its the crankshaft that you need to heat, and not the bolt and that will change the crankshafts temper, damage the oil seal (front crank seal) and lots of bad possibilities amount from that.

Some people rely on starter torque by wedging a socket on a breaker bar against the floor and hitting the key. Attempt that at your own risk, the chances of allowing the crank pulley to turn on the crank key-way and cause further damage has to be recognized.

My husband, Bob, drilled a .062in hole through the flange which is forged integral with the bolt, injected penetrating oil, let it sit for a day, applied air impact wrench- no effect. Repeated this three or four times with a day's penetration time each - still no effect. This hole does not enter the shank of the bolt.

He has now fabricated a suitable tool. 4 ft long steel bar with close fitting pins which fit the holes in the damper/pulley. Impact-grade socket plus impact grade extensions allow breaker bar with pipe extension outside the fender-well.

Initial attempt with this rig did not budge the bolt.

Measurements from the new bolt, which he bought, show it to be a 16mm bolt. The head is marked 8, which the Toyota manual cross-references to class 8T. The specified installation torque for this bolt is 181 ft-lbs per the Toyota manual. He assumes that a significant part of that torque is between the outer edge of the forged-to- the-bolt flange which is what contacts the pulley and the pulley. Flange diameter is ~1 1/2 to 2in.

That same torque/friction will exist when attempting to loosen the bolt. Therefore, much of the torque being applied to remove the bolt, isn't being transmitted through the shank of the bolt to the threads. The present plan is to support the fixture which holds the pulley, put a suitable weight on the pipe which extends the breaker bar, and let it sit for a day or two to see if the assumed thread locker creeps over time. He's at a loss how to make a good estimate as to how many ft-lbs to apply by that long lever.
Naturally, he's worried about twisting off the bolt.

He also now has access to a larger air compressor at a different location which we can bring over.

Suggestions, comments, and ideas requested and welcomed.

Bob has appreciated your previous comments on this matter.

Got the bolt out today! After having soaked it with a penetrating oil for a few days, we set it up with a 200 ftlb load for 24 hours to no effect.

Took the static load off, pushed on it with a long lever arm and Snap! it came loose & Bob could unscrew it with his bare fingers.

The contact area between the flange on the bolt and the damper is much wider than he would have expected from the design of the bolt and is not in the recessed area of the flange at all, but extends about 3/8" inward from the inner edge of the recess.

This area showed heavy score marks from where it was rotated against the damper. Once the bolt was out, the damper came out with no more than hand pressure, no corrosion on the shaft or the bolt.

No visual evidence of any loctite on the threads of the bolt.

He has a new bolt from the dealer that came coated with some loctite type material.

The water pump for sure is the cause of our problem. There was an large amount of play in the shaft but no coolant leak through the seal.

That's the story. Thanks for your earlier comments. They were helpful.