Jason81NA,82RBtt Posted April 1, 2009 Share Posted April 1, 2009 I'm needing some advice on getting a broken exhaust stud from the head of a l28 while the engine is in the car. I've never had any luck getting the drill bit to stay centered, most of the time the stud doesn't break evenly enough to get a good start. Any advice would help. Thanks. Quote Link to comment Share on other sites More sharing options...
WizardBlack Posted April 2, 2009 Share Posted April 2, 2009 I'm needing some advice on getting a broken exhaust stud from the head of a l28 while the engine is in the car. I've never had any luck getting the drill bit to stay centered, most of the time the stud doesn't break evenly enough to get a good start. Any advice would help. Thanks. Post a pic if you can? Use a punch to start the bit spot. Quote Link to comment Share on other sites More sharing options...
freakshow Posted April 2, 2009 Share Posted April 2, 2009 Which stud broke off? On mine the front stud broke off. I drilled it out, and retapped it to the next size up stud. Get yourself some double tipped drill bits. They stay centered way better than the cheap ones, or hit it with a punch. I strongly suggest tapping out to the next size up stud. When I reassembled my intake/exhaust the rearmost stud started to bend over, so i drilled and tapped it to the next size op stud. It wasnt real hard to do, and nissan left a lot of room for error with thier design, just try to keep the drill very straight. If its one of the middle studs, I dont know, get some pb blaster, let is sit overnight, and drill it out and try some easy outs. I dont remember, but maybe they can be upsized too. Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted April 2, 2009 Share Posted April 2, 2009 Assuming it is broken off below the surface try this. Get a gasket and a piece of 1/4" flat stock about 3" x 6" (I'm guessing at the needed size here). Lay the gasket on the stock and carefully mark holes where three bolts go through (including the hole with your broken stud). Drill two holes to exact size (I think it's 8mm). Drill the hole for the broken stud to 1/8". Bolt that plate to the head and use the 1/8" hole as your drill guide. It will help center the drill. It also helps if you use a double point bit as they have less tendency to 'walk'. Use progressively larger bits to clear the stud out. You should be able to save the threads with just a tap. Quote Link to comment Share on other sites More sharing options...
FlatBlack Posted April 2, 2009 Share Posted April 2, 2009 My P79 had two broken studs in it when I put it in the car the first time. I just wanted the car back together, so I waited until I pulled the head for a new head gasket to fix the broken studs. I'm not sure if this is the 'proper' way to do it, but I helicoiled both studs, and I have not had an issue with them. No exhaust leaks at all. I was also worried about expanding the hole, but there was enough metal to do it. Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted April 2, 2009 Share Posted April 2, 2009 Helicoils are great and timesets are excellent, even if you're not repairing damaged threads. Quote Link to comment Share on other sites More sharing options...
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