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MC97GQ
31st July 2012, 07:46 AM
Good morning all,

I need some advice regarding a snapped exhaust manifold stud. It is the top stud on No:1 cylinder and it is broken off flush with the head, I am thinking of trying to fix it today as I am sick of the exhaust manifold leak, so I am trying to find out some information.

1. Is it better to try to get the broken stud out(drill and use easy out) or is it better to drill and tap a new thread.

2. What size thread are the original studs, I assume they are metric and are they left or right hand thread into the head.

3. Is there anything I need to be on the lookout for if I tackle this job.

Any tips, tricks and advice would be greatly appreciated.

Thanks

Mark

Bigrig
31st July 2012, 07:54 AM
Hey boss

I'm thinking easy out as drilling will put filings into the head - at least attempt the easy out as the first option ... others may know of tricks for this, but I did one on mine when the engine was out about 8 months ago and so long as it isn't seized, they come out ok.

Good luck with it.

97_gq_lwb
31st July 2012, 09:09 AM
Be careful not to snap the easy out off in their though as they are hardened and then you run into a big drama.
I have had a lot of success by getting a nut in place and welding the center to the existing thread and then undoing it the heat from welding it on helps as well.

BigMav
31st July 2012, 09:49 AM
Mate I had the same problem, same stud too, I used an easy out in the end with a lot of heat aswell. A right angle drill if you can get one is great to get in there. Also it probably goes without saying but centre punch carefully EXACTLY in the centre of the stud otherwise you will have dramas for sure. Good luck

Winnie
31st July 2012, 09:54 AM
When I got my extractors put on the exhaust guy told me that the studs were gonna snap, he said it's a very common thing with them, he said he just used an easy out with heat.

nissannewby
31st July 2012, 01:06 PM
Left hand drill bit also can work. As much of pain it might be take it for a run and get it warm then attempt this as it will make it easier to come out. Im with the others drill and easy out. They are only an 8mm rh thread easy enough to get a hold of if repair is needed. The other option if you can is to sit a nut over the top and tack it with some weld then you may be able to just wind it out.

Morton
31st July 2012, 08:01 PM
if you're worried about shavings when doing any drilling, punch the centre for a mark, cover area to be drilled in a little vaso & all shaving are caught in the mixed, simply wipe clean on completion of drilling, not really an issue in this case.

FYI
Same technique applies to drilling asbestos but use shaving cream, works a treat & is legal

MC97GQ
31st July 2012, 08:39 PM
Hi guys,

Well the day turned to crap, I thought I would perform a simple operation, turns out the head is shot.

But you have to look on the bright side, the weather is crap down here, so no work for the moment, so if the trucks gotta be off the road it couldn't be a better time.

Manifold turned out to be warped as well(explains the massive exhaust leak), so getting that decked.

Wasn't how I hoped the day would work out, but at least I can sort out a few niggling issues.

Thanks for all the replies, I will keep you posted.

Mark