My jag mechanic and I were fitting a new front seal to my 2001 XK8, I have never seen a bolt in so tight!!!...after gently pushing on the large bar the bolt Sheared!!
I have no idea how to remove part of the bolt that is so tight any suggestions would be very welcome.
Looking on youtube they all seem to suggest drilling a hole in the bolt and using a tool to reverse turn the bolt so it undo's...but this bolt is in there so tight I cannot see that working???
I have attached a picture of the sheared bolt it may be good to know how much is left still in the crankshaft??
Has anybody had this problem before and how did you solve it?
I am pulling my hair out at the moment trying to fix this problem...I REALLY need your advise....Thank you

 

The only way I've ever removed a snapped bolt is by drilling a hole in it and using an easy out. Try squirting some WD40 or thread lube on the remaining threads to help ease removal. Good luck.

 

You have taken the tension off the threads so it won't be as tight as originally. Drilling and easy out is the way but drilling a central hole is the problem. You may have to turn up a guide for the drill

 

The thread locking compound used on the bolt may still be present and THAT is going to be a problem.
When I worked at the dealer I had a bolt that was galling the threads when I was trying to REMOVE the bolt.
I finally got it out and after talking with Jaguar Tech Line, they wanted me to replace the crankshaft!!!

I wanted NO PART of that fiasco!
I fashioned a 'tap' from a used bolt by cutting grooves in the threads with a cut-off wheel and carefully went in the crank a little at a time.
The thread locking compound clogged the 'tap' and some metal was scraped out but I got the hole cleaned.
Put a new bolt in and tightened everything up. FIXED.

You are going to have to get a hole DEAD CENTER and keep enlarging until the threaded pieces 'crumble' inside the crank.
Retap the threads ('chase' them) and try a new bolt.

I wonder if you could over-size the hole and 'heli-coil' to the correct bolt size? if the threads are too damaged.

All this will be easier if the engine was out of the car and you can look at the hole 'straight-on' instead of working on it above or below.
Good Luck. (I don't envy you)

 

If you take your new seal out you could put some heat on it to destroy the loctite .
If the worst comes to the worst replace the seal and weld the pulley into place . You can always grind it off in future ....that should inspire you to do it right and not to buy cars from me !!

 

Counting the threads it looks like you have about 3/4" of the bolt left in the crankshaft. If it were me I would remove the timing cover to heat the shaft with my acetylene torch where the piece is in the crankshaft. I don't like heating the shaft with the cover in place. The cover is aluminum and can warp or melt easily. I know it is a lot of work but if you break an easy out off in the crankshaft you will be in a worse condition. The bolt is torqued to 380nm.

Best of luck to you.



Best of luck

 

If you use an oxyacetylene torch you can get a very small flame and go straight in onto the end of the bolt ...you done need it that hot 150 deg C will shift it

 

Hmm. Scarry...

Did you say a mechanic did this?
Will they eat all costs of what comes next?

How deep inside the shaft is the remnant?

Anyways,,, I don't know if you've done this already BUT remove everything you can and need to give yourself the best possible vantage for ANY work you do. And don't take the chance of doing ANYTHING until you do...give yourself right room.

That means the items already mentioned, all of the cover, the balancer, the rads, oil cooler hoses, etc etc, even the hood. The front large one piece front end.

I recently pulled the engine out of a naturally aspirated xk8 and honestly, it wasn't that bad at all. There is NO headache in the pull engine process that would compare to the pain of having to get a new engine - or replace to the crankshaft - which doesn't seem like an option at all. Too costly.

Pull the engine? It's honestly not that bad.

 

Breaking off any kind of a reverse thread easy out is a dangerous dangerous proposition...

If a hole large enough can be drilled out and a good strong bolt could be welded into RHAT hole that might be an option....? That way you would have something to put a socket on and slowly turn as you HEAT with a torch burning out the loctite...backing it out.

Sheared bolts are the worst. Captain Obvious here, smh
Good luck!

 

Also,,, did y'all have the bolt turn AT ALL before it gave?

 

try a bolt buster and an air chisel. maybe even weld a new head onto it

in fact a bolt buster makes this job easier no matter what

 

How many threads are visible and intact within the Crank? Is it none - did the bolt shear flush with the hole entrance ?
I was just comparing the bolt lengths and wondering how deep the failure is.

 

All good questions....I wanna know too.

 

I would use a magnetic induction tool to burn the bolt out. There are commercial one that will vaporize the bolt and the ones you can buy from Harbor Freight that will heat it to very high temps and facilitate removal.

I have used a commercial one to remove a broken screw from an irreplaceable throttle body. It burned the broken bolt right out of the aluminum and didn't damage the threads.

 

I meant to mention that not many places have induction equipment. I live in a huge shipyard town (Newport News Shipbuilding) and machine shops here are sophisticated. It was no problem to get this done. In a smaller area, you might have to send the part out.

 

Thank you all for your suggestions.

We had almost managed to undo the bolt before it sheared off, we are going to try to drill it out next weekend and fit the new bolt in.

Regards, David ( ex Nuneaton lad now in Orlando)

 

The continuing saga!!!!!!
We managed to drill a hole in the original bolt, and measuring the broken bolt against the new bolt (see pictures) It looks like about 4/5 threads are holding the bolt inside the crankshaft?
So we decided to tap out a 3/8 inch thread into the trapped bolt and screw in a new 3/8 hardenedd bolt to hold the harmonic balancer on (and hope for the best!)

However as we were tapping out the 3/8 thread the Tap Broke!!! Now we had part of an original bolt, I would say 4/5 threads and an 3/8 tap stuck inside the crank! (see pictures)

Now we had the worst situation possible....so I started to drill out the tap with a diamond hole saw? (see pictures) after 3 days drilling I now have a 3/16 hole in the original bolt plus bits of the 3/8 tap.

I put a square Mayhew Pro 37332 Screw Extractor inside the hole to try and remove the bits of the tap remaining....NOTHING< could not turn the tap at all. So removed the extractor.

So this weekend we are going to try to remove the tap, big bar, heat etc....then retap a 3/8 hole for the new 3/8 inch bolt.

Question: will a 3/8inch bolt hold the harmonic balancer off with only a few threads, plus gobs of Loctite???
Worst case condition if we have to try to drill out original bolt can we tap new threads into hardened crankshaft? my jag mechanic says NO we cannot tap the crank!

Any suggestions PLEASE before I lose my mind totally.
Many Thanks, David

 

slather loctite 660 on the crank surface i guess

 

Please tell me that y'all have put a ton of heat on that to burn the thread locker already??? Anyways, yeah, scary...

Looks like the TOP of the bolt is flush with what is actually the end of the threaded section of the crank??? The other hole is just the hole at the end of the crank, not threaded and larger than the OD of the bolt, correct?

Ok... Although it's somewhat deep inside the larger unthreaded section of the crank end (larger than the OD of the cut out in the crank shaft that I'm guessing is about what, a half inch deep) tell your mechanic to (gravity is not going to be on your side) and try an pool some weld material down into that hole!!!on top of the bolt...

The molten weld material will also form around the nooks and crannies of that sheared tap, which is a good thing, maybe...?

use a welder with shield gas, a long stretch of .030 wire extending out of the nozzle of the welder so it will be arching on the BOLT head way down in there. Several short bursts,,, hot! with gas feed! and begin pooling material in there using a short length of right sized copper tubing to direct it and keep it OFF the walls of the unthreaded section but ON the bolt top...

Use a section of copper pipe that is just SMALLER than the diameter of the bolt so as not to get material on the seam between the crank and bolt. Y'all will HAVE to figure out a way to best center it on the bolt head for the first couple blasts. And maybe a copper tube inside of a copper tube inside of a copper tube. Layer them!?

The heat will also fry the red thread locker that is what most likely caused this problem in the first place...

Once you have built up enough material,,, weld a LARGE bolt to the top of the material and give her a whirl...

That's all I can come up with.
This is an F'd up situation.
​​​​​​​Captain obvious here.

 

Thank you very much for your help and I will show your instructions to my jag mechanic!