alright quite a while back my exhaust got smashed by a huge rock and when i got under the car i noticed a bolt was missing on the passenger side. so i go to tighten it up and all of a sudden the bolt falls out with most of the threads and the pipe wasnt even close to flush. so since then i have bought some heli coils and have straightened thet pipe. now the guys at the parts place said i needed a special tap. is he lying to me, and has anyone done a heli coil on exhaust. its a 10mm by 1.25pitch bolt. im going crazy not being able to drive my car. also all i know about the coils is whats on the box,

 

770-3025

M10x1.25

Metric

Thread

Repair

Inserts

Yes, special size drill bit and tap for doing a Heli-coil. Drill out hole, tap in threads, insert Heli-coil, install normal bolt into new threads.

but what size hole and tap pitch

You need a special Heli-coil tap, its not a standard size.

crap! the kits are like 60 bucks.

10 mm is close to 7/16'' right? cant you just drill out the heli coil a little bit, then put in a 7/16'' bolt after you tap the heli coil to 7/16''?

 

 

 

 

 

~Josh~

no, heli coils are like little springs.

I used the 7-16th on mine, worked like a charm, use 7/16th bolts and you'll be good to go.

crap! the kits are like 60 bucks.

Last time I got a heli-coil single-size kit (a year ago?) it was only about $20. Do you have the install tool, or did you just buy a package of coils?

 

11mm x 1.25 might be a better choice then 7/16th inch. Approx same size as 7/16ths, same size and pitch as head bolts, and keeps it metric (I hate mixed-standard vehicles).

I also found that 7/16th is an odd size. Home Despot doesn't have then and the ones at the autoparts stores are often too short. Solved it by buying one that was 3 inches long and hacking it down.

I also found that 7/16th is an odd size. Home Despot doesn't have then and the ones at the autoparts stores are often too short. Solved it by buying one that was 3 inches long and hacking it down.

Are you talking about it being an odd size for bolts??? If so, not around here. :-\

see, i have the coils i just didnt buy the tap or install too because i figured i could use the bolt to install it and the tap would be some normal size. guess i will have to save my money, man my subaru hasnt been going for like 2 months now, its driving me crazy.