As I continue my crawl through the valley, I have decided to hire a welder to attach a nut or a shaft with head to the broken steel bolt above (This bolt is one of the 5 attaching the water pump on an 04 XJR.). I have come to this conclusion after so many thoughtful posts by so many of the great guys on this excellent forum. Thank you, thank you, thank you!

If you have first hand knowledge of this process, please alert me as to any potential snares to be avoided or procedures to help assure success.

My list includes: Make sure the welder is competent and knows the risks of too much heat melting or distorting the aluminum.

Should I be concerned with issues like preheating the aluminum to prevent thermal shock? Should I insist on TIG because, I read, it is easier to focuse the heat onto the subject than others? I assume that the welding will be "pulse welding"? Any guidance needed on specifying the filler rods used? I suspect the welder will know what to use in joining steel to steel?

I decided to do this procedure first because, if it fails, I have options that I wouldn't have if I bored...

Does anyone with knowledge of the steel used in the bolt have any guidance as to how to specify what steel should be welded to it! I like the idea of a smaller shaft with a head or a welded nut? Since the broken bolt is a 6M would a 5M be to large? In other words, what do you think the ideal would be?

Thanks & best,

Steve S.

 

Only a few suggestions from fighting broken bolts?

Use a left hand drill bit to drill a hole in the broken stub. Sometimes this alone will grab and remove the bolt.
Yes welding a nut can work but with no stub this might prove difficult to do?

Have you showed this to a welder to get his opinion? I do think TIG would be better.
I would place a nut over the broken stud and then fill the hole in the nut with the welder set on a high setting. As you said fast intense heat will be best and with Aluminum all around the broken stub you want to try and limit how much heat is put in the surrounding area's.

But the stud is 90 degrees from vertical so just holding the nut in the right position for welding can be a chore. Possible that the welder will need a second set of hands to hold things so maybe you could help out?
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I will certainly volunteer a second set of hands. I wouldn' miss this!

 

Just stay TF out of the welder's work area and let him do what he already knows how to do best.

Pay him well. Partly so he doesn't try to take YOUR JOB as 'payback'.


Or take a full multiple-thousand hour formal apprenticeship for your certification testing.

Just that "binary" a choice. It's QTY ONE bustid bolt. Not an HY100+ nuke sub pressure hull.

"Mission type orders" as taught to about-to-become "loo-tenants":

NEVER tell a Combat Engineer Sergeant HOW to do a thing.
Tell him only what, where, and when a given thing must happen.
Even if it is thought to be impossible.

Then get TF out of his way while he just gets it DONE.
Regardless.
It's what Combat Engineer Sergeants and their teams DO!

"Micro-manage" that proven system, the last sound you hear may be the seared remains of yer **** passing through what's left of yer shattered skull at PETN detonation velocity.


Human expertise in civilian life works exactly the same way.

It ain't that welder's "first rodeo". **** him off at your own risk.

Don't presume to tell a Grandmother how to do ..whatever the Hell she pleases to do . .with eggs, either.

Just smile and thank her for a delicious meal. She, too "had more than one option" in her kitchen.
"Eggs, over easy" ain't the same as "Eggs, Easy-Off"

 

Degrese the area and let him at it. Dirt is the enemy of welding.

 

Steve:
Suggest don't weld.
Carefully drill it out. Use top quality HSS bit and cutting fluid. LH bit is great, if you can find high quality LH HSS bit. Cheap bits will work harden the broken cap screw.
I would use 1/8" bit and square easy out. If this fails, use slightly larger bits until you can start a tap to clean threads. I've removed many, many broken fasteners over the years. Trick is to properly center bit and drill square, using best quality drill bits and slow drill speed.
Welding runs high risk of ruining aluminum timing cover, IMHO...

 

The problem is always drilling the broken stud/bolt dead centre.
In this case if you have the old pump body it will have mounting holes that line up with the tapped holes in the block.
One will line up with the broken bolt. If it is M6 you make a sleeve to fit that mounting hole, probably around 6.2 OD.
Drill the sleeve about 2mm or 2.5mm and that will be for the pilot hole in the broken bolt.
Fit the pump body back on the engine and you can drill dead centre using lots of lube and open it out later.
Helps if you have a lathe to make the sleeve. Chinese lathes pretty cheap and you might find a friend or neighbour has one.

 

As a follow up, hopefully you get the old bolt out and the threads are still good enough.
If the threads are dubious refitting with a bolt is not a good idea.

a) Better to think about a stud in the block. Use a long bolt and cut it to suit.
Loctite have products that will set that stud in a damaged thread so we will all be dead and buried before it fails.
Just in case you cannot get the stud square, go for a slow setting Loctite which allows you to fit everything back together and bolted square before the Loctite fully cures.
If things are not quite square you could drill out the pump mounting hole a bit to compensate.

b) Worst case the threads in the block are trashed. This time drill out the thread square as you can with a 6mm or close size drill.
Make a stud from a bolt which as an unthreaded shank. That shank has to fit the hole with a few thou clearance. Once again fit it with an appropriate Loctite product. If in doubt I think you can phone the Loctite hotline, they are probably happy to tell you all about what they can fix.

 

Threaded - or knurled - is better, actually.

And Araldite 1258 A/B - specifically engineered for the purpose - gives Loctite "stiff competition".

https://www.freemansupply.com/datash...ldite/1258.pdf

 

IMHO, if to drill bolt out and chasing threads with tap do not produce desired results, helicoils is the next best thing. As long as intial hole drilled staright. For adhesive to work, the cure temperature have to be above operating temperature. 100C is too close for comfort.

 

Another vote for Heli-coil if the threads get trashed.
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Welder just left. Very decent fellow. He said as much as he thinks he can do anything and as much as he hates to dissappoint, he thinks that welding right on the gasket might do more harm than good. RichardJags, Hisport, and Big Guy, Koska you're on.

Candidly, I don't think that the bolt made much difference. WP has been leaking about 1/4 cup every three or 4 weeks; hasn't changed since the bolt broke.

I need to remove the pictured fly wheel. It appears to be two bolts. Is there anything more to it? Assuming one doesnt break, I will put together the boring strategy.

 

Actually, it is not just 2 bolts. the #15 axle bolt has to come out first because one of the the #8s needs more room. The axle bolt seems kind of hard to turn; any secrets?.