Rear Exhaust Broken Cover Bolt Removal

[Okie2ee]

Looking for recommendations on how to repair the broken bolts that hold the rear exhaust joint cover.......................plan at present is to remove the the cast iron exhaust manifold pieces and then try to drill out broken bolts and extract them...........any suggestions based on past experience would be greatly appreciated...........thanks

 

[02GF74]

My 2 tips, which others are free to disagree, from experience are:

1. Clamp the item securely in a drill press, using a hand held drill is likely to end up snapping the drill bit in the bolt which is even harder to extract. (I belive FM said this recently)
2. Avoid using extractors, again if they snap, as recently posted, the task becomes even harder. Instead get the drill centred as best you can, and drill in increasing drill diameters until the last drill is same as the bolt minor diameter, then using a scriber, pick out the thread or run a tap.
3. Apply heat.

 

[Okie2ee]

Thank you.............basically followed the same procedure but did not bother to jig up the part in order to hold it firmly in place and aligned with the drill bits...................hand drilled a hole thru the bolt and then went to the drill press and finished drilling an oversized hole in the casting............did manage to break off two small drill bits but was able to work around, caution on drilling is very important................I found that trying to center punch the bolt was damn near impossible, there's probably some special machinists device out there to do that.................holes weren't straight, but I planned on installing a stud...............bought 10X24x2 1/2" machine screws and installed them with the head on the threaded part of the casting..................installed the covers on the screws for alignment and the brazed the head of the screws to the casting...............now I have to fabricate some special threaded nuts to fit inside the recesses in the covers..............may not be pretty but will paint it black and probably won't show..................at least I won't have this problem again..............should have been a stud from the factory.................I applied heat with no movement at all of the bolt

 

[one2dmax]

Probably easier to get another one that doesn't have a broken bolt! I have a few good ones on hand. Email me at [email protected]

 

[johnissan]

Yes it is easier to get another part to do your job!...but because i'm very egoist i alwayw looking the hardest way to fix things!...in this senario i always drill this parts with a very quality 5.5 mm drill slowly . Make then new 6x100 metric thread and use a new allen screw! And if you don't to open the aluminium cover to put the bigger allen screw you can use a hand drill to hold the screw and with a metal shaper you can do the head of the allen screw smaller!
That is how i use to do my life difficult!
Sorry for my English...i'm from Greece.

 

[Okie2ee]

This is what I ended up with..............


Next step is to trim the 10x24 studs down and add chrome acorn nuts which are on their way............the small sleeves were made from brake line..................so far so good................

 

[johnissan]

Yes something like that as well....why not!...and with the chrome acorn nuts will look pretty!...

 

[Fire-medic]

Try a soda blaster to make those exhaust shields sparkle! The bicarbonate of soda is good for getting into pits in chrome, to clean 'em-out. It should remove the paint too. Home Depot for the 12 lb bags, $9 ARM & HAMMER:Arm and Hammer Arm and Hammer 12 lbs. Baking Soda Pool Cleaner-01192 - The Home Depot It's cheaper than the HFT 50 lbs. bag.

15 lb. Portable Soda Blaster (harborfreight.com) $100

40 lb. Portable Soda Blaster (harborfreight.com) $130

Soda Blasting Media - 50 Lbs. Medium Grade (harborfreight.com) $43

 

[Okie2ee]

Thanks for the suggestion on soda blasting and where to get it.............didn't realize Home Depot carried it..............I have small portable sand blaster and have considered trying soda blasting...............I was involved with soda blasting in the manufacturing of medical needles and it works well......................the covers do need a loving touch to make them look nice again................

 

[Fire-medic]

Thanks for the suggestion on soda blasting and where to get it.............didn't realize Home Depot carried it..............I have small portable sand blaster and have considered trying soda blasting...............I was involved with soda blasting in the manufacturing of medical needles and it works well......................the covers do need a loving touch to make them look nice again................

Soda blasting is a good choice for oxidation/deposits or gunk on things like carbs, chrome, and anything that you don't want patterned from the blasting. On chrome headpipes or canisters, it gets into the pits and cleans 'em out well.