tech quizzie (Exhaust Studs)

[darthsoob]

While investigating why my exhaust has gotten a might louder, I discovered to my dismay that I have somewhere along the way dropped one of the studs holding the exhaust pipe to the head. Question: before I have to resort to backing one of the other studs out for comparison, does anyone in the Soobie Universe happen to know what size the stud is, i.e. length, thread, grade, etc? Thanks All,

Brian

[asavage]

http://usmb.net/repair/?CurrentDirectory=FOLDER_3f29dd8b798ae3.96104436/&FileType=Article&File=ARTICLE_3f3c61f742ce63.72352405.art

 

and

 

http://usmb.ultimatesubaru.org/forum/showthread.php?s=&postid=35512#post35512

 

It's 10mm x 1.25

 

I didn't measure the length, because I took a sample in to the parts store. It's approx. 1.25" long overall. I may have one of the old ones in a box somewhere, if you need an exact measurement.

 

My receipt says "DOR 675-359" which is a Dorman part number (the orange metal cabinets you see in many parts stores are Dorman).

 

My parts store only had two in stock, and had to order the third one I needed. The helicoil set I had available, as well as the drill bit. Both are odd sizes.

 

I disagree with something in the USRM article: I did not need two inserts per hole, but then I was doing an EA82, not an EA81, so that may be the difference. Or, it may be that the author was using shorter inserts: they are available in many different lengths.

 

Also, a gotcha: you can't leave ANY of an insert above flush when you're done: that's a big no-no. Running a too-short insert in below flush is OK, though, but there's no advantage (unless you're ganging up inserts, like the USRM article's author). I had only one length of inserts available to me. In the past, I've carefully shortened inserts before inserting them. This time, I drilled the holes a tad deeper (about 1/8"), thinking that would be enough to run in the longer inserts, and then I ran the Helicoil tap to the very bottom (top? ) of the holes, and on two of the inserts, they still hung out of the holes about 1/2 turn. I used a Dremel tool to carefully cut into the side of the remaining insert, just below flush, then grabbed that last half-coil with needlenose and bent in back and forth a half-dozen times, breaking it off. Works fine. It's OK if the Dremel stone notches the head a little, it's not a sealing surface.

 

Alternatively, you could buy shorter inserts, or pre-cut them one coil shorter, which is what I would probably do, now that I know how close they are to (not quite) fitting in length.

 

I can get the size of the inserts I used, if you want. They're the default size in the kit, but our kit is probably several years old, and Helicoil may have changed the default size they supply.

 

The Helicoil kits do not come with the drill bit that you need. You will also want to use a drill angle adapter to keep the drill motor perpendicular to the head, or be very very careful when drilling the hole, to do it by sight and feel (which is what I did, because I couldn't put my hands on my drill angle adapter, it's in storage somewhere, I don't use it much). And one of my studs isn't quite square, but the holes in the exhaust flanges are generous, fortunately.

[darthsoob]

Thanks for the info, Al. Pointing out the repair manual items was a good read. I inspected the hole that the stud dropped out of and it appears to be "intact" and I can still see threads. Hopefully all I will need is the replacement stud. By the way, in what parts store did you find yours studs?

Brian

[asavage]

I bought mine at WestBay Auto parts, a small (eight store) regional chain in Kitsap county and Olympic Peninsula areas.

 

http://www.westbayautoparts.com/

 

But a lot of stores carry the Dorman products line. And, of course, a lot of different mfgrs offer metric studs.

 

I couldn't find one of my old ones, I must have actually cleaned up after that job But 1.25" long is pretty close.

 

You can look up that part number:

http://208.233.99.171/randb/buyerbrowse.epc?reset=ALL&categories=%20&category1=Threaded%20Metric%20Fasteners

That URL gets redirected to one with a cookie. Then, ignore the products listed, and from the red nav bar, choose "Part Number Search" and next page, type in "675-359". It'll tell you:

 

Item Number: 675-359

Description: Double-Ended Studs Class 8.8

Brand: SHOULDER

Application: 7mm

 

Attributes:

A : Thread Size

M10-1.25 : A

Thread Length : 21mm

B : Thread Size

M10-1.25 : B

Thread Length : 13mm

 

So, it'll tell you the thread lengths but not the overall length. Well, that's a computer for you.