• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

Replace Exhaust Manifold Studs?


Bronco648

Active Member
Joined
May 23, 2019
Messages
414
Reaction score
102
Points
43
Location
Chicago-land, Illinois
Vehicle Year
2011
Make / Model
XL
Engine Type
2.3 (4 Cylinder)
Engine Size
2.3
Transmission
Automatic
2WD / 4WD
2WD
Tire Size
15"
The studs on my exhaust manifolds have seen better days (I'm talking about the studs that hold the Y pipe to the manifolds, not the bolts that hold the manifolds to the heads). There's a nut right where the stud meets the casting. At this point, is there any chance that they will simply unbolt? The manifolds are from Oklahoma and are not that rusty.

Or, am I better off running a die over the threads to clean them up and get new nuts?

Lastly, is there any chance you could cut new threads by going one size smaller (say M8 to M7) if the thread pitch was the same?

TIA
 


Uncle Gump

Token Old Guy
TRS Event Staff
TRS Forum Moderator
Supporting Member
VAGABOND
TRS Event Participant
Joined
Sep 17, 2018
Messages
13,700
Reaction score
13,159
Points
113
Location
Ottawa IL
Vehicle Year
2006/1986
Make / Model
Ranger/BroncoII
Engine Size
4.0L SOHC/2.9L
2WD / 4WD
4WD
My credo
Lead follow or get out of my way
Heat them up good... quench the stud with some PB... they will most likely come out.
 

Bronco648

Active Member
Joined
May 23, 2019
Messages
414
Reaction score
102
Points
43
Location
Chicago-land, Illinois
Vehicle Year
2011
Make / Model
XL
Engine Type
2.3 (4 Cylinder)
Engine Size
2.3
Transmission
Automatic
2WD / 4WD
2WD
Tire Size
15"
Heat them up good... quench the stud with some PB... they will most likely come out.
I do not have an oxy/acetylene set-up. Would MAP gas work or isn't that hot enough?
 

Uncle Gump

Token Old Guy
TRS Event Staff
TRS Forum Moderator
Supporting Member
VAGABOND
TRS Event Participant
Joined
Sep 17, 2018
Messages
13,700
Reaction score
13,159
Points
113
Location
Ottawa IL
Vehicle Year
2006/1986
Make / Model
Ranger/BroncoII
Engine Size
4.0L SOHC/2.9L
2WD / 4WD
4WD
My credo
Lead follow or get out of my way
I think that would work...
 

Bronco648

Active Member
Joined
May 23, 2019
Messages
414
Reaction score
102
Points
43
Location
Chicago-land, Illinois
Vehicle Year
2011
Make / Model
XL
Engine Type
2.3 (4 Cylinder)
Engine Size
2.3
Transmission
Automatic
2WD / 4WD
2WD
Tire Size
15"
This is what they looked like when new, good luck.
I didn't realize they were two different sizes. :unsure: Maybe running a die over them would be a better idea. @AndyB. Do you know the thread size and pitch by any chance?
 

AndyB.

Active Member
Joined
May 26, 2014
Messages
465
Reaction score
137
Points
43
Location
Cincinnati, OH
Transmission
Automatic
M10x1.5 was the closest match I had, but it wouldn’t chase these cleanly.
 

Bronco648

Active Member
Joined
May 23, 2019
Messages
414
Reaction score
102
Points
43
Location
Chicago-land, Illinois
Vehicle Year
2011
Make / Model
XL
Engine Type
2.3 (4 Cylinder)
Engine Size
2.3
Transmission
Automatic
2WD / 4WD
2WD
Tire Size
15"
M10x1.5 was the closest match I had, but it wouldn’t chase these cleanly.
Hmm, OK. With a pitch gauge I was able to determine that the pitch was 1.5 and M10 is the only thing that fits, diameter-wise. Why would these studs be something special/weird (rhetorical question)?

Edit/Update: I ended up trying an Irwin/Hanson M10x1.5 hex die. Like @AndyB. said the threads did not clean up like new but they're certainly better than they were. I'll be using new flanged Stover (thread distorting lock) nuts and that should work just fine. Don't forget that these are 38 year old studs and most are rusted beyond use. I consider myself lucky that they cleaned up and are usable.
 
Last edited:

4x4prepper

Active Member
Joined
Feb 2, 2015
Messages
507
Reaction score
215
Points
43
Location
Atlanta
Vehicle Year
1985
Make / Model
Ford
Transmission
Manual
> I was able to determine that the pitch was 1.5 and M10 is the only thing that fits, diameter-wise.
> Why would these studs be something special/weird (rhetorical question)?

google:
"Are m10 and 3/8 the same?
That said, they are very close, the 3/8" bolt is about 0.019" smaller and the pitch's are very close so the 3/8 -16 bolt will thread in the 10mm x 1.5 but the 10 x 1.5 bolt will not fit the 3/8 but.."


But, to make it worse, they are probably pipe thread 🙃

> At this point, is there any chance that they will simply unbolt?

I suppose there is a chance. When I have had to remove them, for various Fords, I have had to grind them flat and drill them out, and then use regular grade 5 or 8, 3/8" bolts in their place. My expensive stud removers get little use on exhaust systems.

There are aftermarket gizmos that will clamp your exhaust on using the remainder of the stud. If the threads are too loose you can always try copper leaf. Or have an exhaust shop tack weld on a new stud over the old one.
 

Bronco648

Active Member
Joined
May 23, 2019
Messages
414
Reaction score
102
Points
43
Location
Chicago-land, Illinois
Vehicle Year
2011
Make / Model
XL
Engine Type
2.3 (4 Cylinder)
Engine Size
2.3
Transmission
Automatic
2WD / 4WD
2WD
Tire Size
15"
They seemed to clean up OK with the M10x1.5 hex die. I haven't tried to hook up the Y pipe but it might work out OK. We'll see.....
 

Sponsored Ad


Sponsored Ad

Staff online

Member & Vendor Upgrades

For a small yearly donation, you can support this forum and receive a 'Supporting Member' banner, or become a 'Supporting Vendor' and promote your products here. Click the banner to find out how.

Truck of The Month


Kirby N.
March Truck of The Month

Recently Featured

Want to see your truck here? Share your photos and details in the forum.

Follow TRS On Instagram

TRS Events

25th Anniversary Sponsors

Check Out The TRS Store


Sponsored Ad


Sponsored Ad

Sponsored Ad


Amazon Deals

Top