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I know this has probably been beaten to death, and yes I have searched every single post on the subject, but I am in the process of replacing my tensioners/chains, and am stuck at the removal of the harmonic balancer bolt. Using the appropriate holding tool, and a 24mm socket with e breaker bar and a 4' extension, the bolt slowly began to undo with all the might I could muster. After undoing the bolt approx half a turn, I removed the 48" extension and began unwinding the bolt with just the breaker bar, it still had at least 120ft lbs resistance. This resistance increased the more I tried to undo the bolt, until after approx a full turn the resistance increases to such an extent that I am afraid of snapping the bolt. What's the deal here. The bolt has "broke loose", and in theory should now remove relatively easily. I have tried tightening the bolt again, and loosening again, thinking it may loosen it up, but no luck. I had soaked it in WD40 and PB Blaster. When I try to undo it just gets harder and harder to turn, until it takes so much effort I am afraid of snapping the bolt. I have not tried an impact wrench yet because I am afraid of snapping the bolt, as I cannot understand why there should be so much resistance AFTER the bolt has been broken lose. I cannot think why or what is causing this resistance. Anyone else had this problem, and any ideas? It's frustrating because getting this far has been very easy, and I'm spending more time on this stupid bolt than the actual job!
Spray it with the PB Blaster while out as far as you have it, ....re-tighten it, but not tightly, ..back it out again, ..spray again, ..re-tighten again, repeat one more time...let sit for awhile. That will help you remove scaling on the threads and get the penetrate into the inner threads to soak in deeper. Read the can, it tells you to apply solid raps to the bolt. In your case use your socket on it and apply some hammer blows. This is to loosen the scaling.
...btw, is that a 3/8" drive? If so, you need 1/2" to get proper torque.
Spray it with the PB Blaster while out as far as you have it, ....re-tighten it, but not tightly, ..back it out again, ..spray again, ..re-tighten again, repeat one more time...let sit for awhile. That will help you remove scaling on the threads and get the penetrate into the inner threads to soak in deeper. Read the can, it tells you to apply solid raps to the bolt. In your case use your socket on it and apply some hammer blows. This is to loosen the scaling.
...btw, is that a 3/8" drive? If so, you need 1/2" to get proper torque.
HighHorse, Thank you for the input. Yes, it is a 1/2" drive, and a impact-grade socket. And I have been tightening, and loosening, and spraying with PB blaster for the last 3 days! It is really hard to get any hammer blows in with the radiator in place, and I am reluctant to remove it as I assume i will lose transmission fluid, and I don't know how to replenish.
Trans line removal is somewhat easy and easy to cap. Take a sandwich bag, laying flat, cut it in half, sealed bottom to opening and get a couple rubber bands or zip ties. Now when you take the lines off you put the pocket corner of the bag over the end of the line and put the rubber band or zip tie around it to prevent drippage. Undo one line at a time, after removal you'll probably get a bit of drip, put a towel or piece of cardboard under the area and cap off.
There's an old trick we used to use, but I don't think you can get into it enough to do such. If you have a torch, heat up the bolt pretty well, take a candle stick and work it around the threads as far down as possible and while still hot, wrench it out. The wax acts as a flux lube and when it starts getting hard to turn, you just need to heat it again and apply wax. But, like I said, this situation really doesn't apply well for this situation.
There's an old trick we used to use, but I don't think you can get into it enough to do such. If you have a torch, heat up the bolt pretty well, take a candle stick and work it around the threads as far down as possible and while still hot, wrench it out. The wax acts as a flux lube and when it starts getting hard to turn, you just need to heat it again and apply wax. But, like I said, this situation really doesn't apply well for this situation.
Heating the bolt was my next move, but I'm cautious about the rubber content of the harmonic balancer. I'm still puzzled as to why the bolt should get harder to turn after being "broken loose', especially as tight as it is getting, it is "solid". . Is it the locktite that it still holding the threads in some sort of way, and surely it shouldn't be strong enough to cause such resistance?
Heat, a damp rag on the pulley and warm it up. The threadloc used is holding it. The new bolt already has it applied, a blue coat if I remember correctly.
I've always used impact wrench on that screw. The contact twisted from an extension is more likely to cause the bolt to snap.
I agree, an impact is probably less likely to snap the bolt than extreme twist from an extended pry bar, I guess I'm just shy about both, I don't need a snapped off bolt in the crankshaft!
Originally Posted by Sean B
Heat, a damp rag on the pulley and warm it up. The threadloc used is holding it. The new bolt already has it applied, a blue coat if I remember correctly.
I can only think you are right about the threadloc still producing resistance on the bolt, I'm surprised how much resistance, I thought once it broke loose it would be fairly easy to remove from then on. Why they need to tighten a bolt to 275ft lbs AND lock it with threadloc beats me, Surely it doesn't have that much torque affect on it as it "only" turns the waterpump/alternator/power steering pump/AC pump.
I guess I'll try the heat, and the impact, and see what happens.
I guess I'll try the heat, and the impact, and see what happens.
I don't think the threadlock can hold the bolt so hard, even though it is the red one (pre-applied to the bolt). It is more likely that the bolt was overtightened and stretched deforming the threads. I would go very slowly with a lot more penetrant/lubricant. Heat should help - try heating it up and back the bolt out as much as you dare then let it cool down. Heat up again, see if you can back the bolt a bit further, cool down and so on (with lots of penetrant in between).
This picture should show how the threads are actually filled with loctite.
I've removed dozens of these things and heat directly on the bolt head gets this stuff soft enough to remove the bolt. It binds as it comes out otherwise.
The high torque setting is for both Supercharged and NA units.
I don't think the threadlock can hold the bolt so hard, even though it is the red one (pre-applied to the bolt). It is more likely that the bolt was overtightened and stretched deforming the threads. I would go very slowly with a lot more penetrant/lubricant. Heat should help - try heating it up and back the bolt out as much as you dare then let it cool down. Heat up again, see if you can back the bolt a bit further, cool down and so on (with lots of penetrant in between).
I am trying the heating, turn a little, cool down, turn a little, spray with PB, heating, turn a little method. I am getting some progress, but it is very slow, maybe a quarter turn each time with about 100ft lbs resistance. But at least it is progress.
The bolt is 1 5/8" long, and approx 12 tpi, and I'm getting about 3/4 of a turn per day, so I should be done sometime in April!
This picture should show how the threads are actually filled with loctite.
I've removed dozens of these things and heat directly on the bolt head gets this stuff soft enough to remove the bolt. It binds as it comes out otherwise.
Well said, Sean. The Loctite "bunches up" as you back the bolt out, actually increasing the resistance.
Originally Posted by Carnival Kid
I am trying the heating, turn a little, cool down, turn a little, spray with PB, heating, turn a little method.
You're right to be concerned about the rubber core of the harmonic damper, but all that metal in the reluctor/damper core, crankshaft and timing cover form a very efficient heat sink, so you can apply more heat than you think directly to the head of the bolt.
I've found that using MAPP gas is often more effective than propane because it has a higher combustion temperature and will get the bolt hot more quickly and thoroughly before the heat has a chance to dissipate into the surrounding metal.
The Loctite "bunches up" as you back the bolt out, actually increasing the resistance.
all that metal in the reluctor/damper core, crankshaft and timing cover form a very efficient heat sink, so you can apply more heat than you think directly to the head of the bolt.
Looking forward to your victory cheer!
Don
My concern levels are very high at this time, and I appreciate all the advice and encouragement, I'm just hoping that it is just the loctite causing all this, and that I don't end up with a mauled/stripped crank thread.
I had this same thing happen to a 4.0 V8 just out of factory warranty. I finally got the bolt out but there was some metal in the bolt threads. I called Jaguar Tech Line and was advised to consider replacing the crankshaft.
I did NOT want to go through the procedure of matching the bearings etc.
The customer would not want to pay the repair bill I'm sure!!
I cleaned the old bolt and cut grooves along the length of the bolt to fashion a TAP and ran it into the crankshaft end several times to clean the threaded hole.
A new bolt from the parts dept and the pulley went back on properly!!! (hooray)
I had this same thing happen to a 4.0 V8 just out of factory warranty. I finally got the bolt out but there was some metal in the bolt threads.
I just installed a new crank pulley bolt on my engine (SC), which came with red pre-applied threadlock. What puzzled me was the specified torque of 375NM whereas I found, in the bolt tightening charts, that the torque for M16 x 2.0 bolts of Grade 10.9 (like the crank pulley bolt) should be 280NM. I understand that some extra torque should be added for the friction under the large bolt head but going to 375NM seems excessive (and risky). Anyhow, I torqued it to about 320NM (afraid to go higher) and I am sure it will hold well. Perhaps the 375NM can, in some cases, cause damage to the thread.
that bolt is unnecessarily tight. has anyone ever broken the bolt? i feel like that would be next to impossible. I took mine out with a 28" pry bar. And yes it was still tight even after breaking loose!
It is not difficult, you don't pull it all the way. Once you pull the pulley a small amount (1 mm or less), just hit it back with a plastic hammer and it will come loose. You may have to repeat a few times, pull-hit, pull hit (just like hot-cold).
It is not difficult, you don't pull it all the way. Once you pull the pulley a small amount (1 mm or less), just hit it back with a plastic hammer and it will come loose. You may have to repeat a few times, pull-hit, pull hit (just like hot-cold).
I had to use a crank pulley puller thing I rented at autozone... there's screw holes in the pulley that you can put long bolts in with this puller.
only thread the bolts into the pulley a SMALL amount (i'd say 4-5 threads of depth is sufficient). If you thread them too far you will crack your timing cover
03-04-2018, 07:43 PM
Crank pulley bolt
