Snapped head stud and alternator mount

[colinthefox]

Now it's a long time since I messed around with a petrol engine, and I've never seen the inside of a 1.9 WBX till last weekend. So I'm looking for a bit of advice from someone with more experience............

Anyway, I'm rebuilding a friends "cooked" 1.9 wbx, it came to me with one head stud snapped right at the top, and the nut rattling around inside the rocker cover! I got all the other nuts off without mishap, so i've got just the one stud to renew.

Is there a favoured method of removing these broken studs, or is it just a question of getting a grip and unscrewing it from the casing. I don't want to end up with a scrap casing if I can help it.

The reason the engine overheated is that the studs holding the alternator bracket had snapped, and the bodged repair put the alternator pulley out of line and at an angle, shredding the fan belt. Someone had previously tried to drill out both the studs, and has left the casing beyond repair, or fitting new studs, in that area. This looks like it might be a regular problem, cos those studs really don't look up to the job at the best of times. Is there a regular fix for this problem? I was going to design a new alternator bracket to use some of the other tapped holes and fixings around that area.

[Ian Hulley]

Is there a favoured method of removing these broken studs, or is it just a question of getting a grip and unscrewing it from the casing.

A mate has done several by welding a nut onto the stud ... getting enough heat down the stud into the base to 'crack' the joint.

Ian

[Bigjcc55]

As Ian says above, or I've used an impact stud extractor, got it off flea bay.
Gave the top of the studs a good clout with a hammer then used the extractor, I had both halves de studded in about 15 minutes.
The studs weren't completely rotten which helped.

[colinthefox]

Thank you both for the advice.

Ian. Yes I had kind of anticipated something involving a welder.

Bigjcc55. Funny you should mention giving them a clout. When removing the head nuts, I was worried about winding the tops off the studs. I found it helped to give the nuts a tap while turning them quite gently. The nuts let go when hit, but were very reluctant without the impact.

[colinthefox]

Pleased to report a good outcome. Thanks again.

Cut the stud off nice and flat at the top. Heated casing locally up to 100C and a bit. Ran oil down the stud to cool it and lubricate. Gripped stud with stillsons. Sharp taps on the end with a small hammer while turning, and hey presto, out it came.

Next question. Do I need to seal the new thread with anything to prevent coolant getting in? Or just bung in the new stud?

Also managed to drill out one of the alternator studs, and it's not a total write-off, but pretty scabby, so I need some advice on Helicoiling, as I'm a Helicoil virgin. Are the kits on fleabay any good, or is there a better way to buy the gear?

[Bigjcc55]

I was recommended by elite just to fit the studs dry.

[infidel]

I was recommended by elite just to fit the studs dry.

that's all well and good, but if you ever need to remove those studs, you are in for a beating.

why not put a spring washer under the nut?

[itchyfeet]

I was recommended by elite just to fit the studs dry.

that's all well and good, but if you ever need to remove those studs, you are in for a beating.

why not put a spring washer under the nut?

Head stud nuts are torqued and have a sealant to stop water leaking you can't use a washer

I have seen silicon used but personally id use dirco

[kevtherev]

I was recommended by elite just to fit the studs dry.

agreed
they are torqued down

dang..you is quick mr feet

[kevtherev]

take a look at time-sert.
alternative to helicoiling and imho better