Seeking input before I jump into the abyss on this one. I have the entire front suspension pulled on my 2000 100 series. Rebuilding the wheel hubs, bushings, etc. at 374K
The infamous cracked-ticking exhaust manifold issues has been there for years and, while staring at the accessible manifolds, decided its now or never. Pulling the manifolds was not a huge challenge once all suspension stuff is out of the way. Got both out and only the passenger side front port showed a crack similar to what others have posted here. I was expecting worse but for a California-based car, the manifolds are in very good shape and the internal runners were very clean. Got it welded up nice and we're good to go.
Now - one of the studs snapped on the flange going into the drivers side cat. I also had 3 studs back out of the head and one stud snapped at the head
. It took about 1 hour to pull the drivers side manifold and it took 2+ hours to extract that one broken bolt. I tried using extractors and went through all three extractor sizes with no luck. Next, I started drilling the center and moving up one bit size at a time as to not damage the threads. I then used a 8x1.25 tap and tapped the bore in hopes of scoring out the screw threads. Once through, went to 9mm and eventually to 10mm. I'm convinced Toyota sources these studs from Satan 
directly. I've worked many snapped bolts in the past but this was a BEAST to extract.
I have a fresh set of OEM studs/nuts arriving soon with the original plan of swapping all of them out fresh. I'm not double guessing that.
I do have Torx E8 socket that I presume would strip the head of the bolt before it would snap off. Arguably there is no rust at the stud or in the head making removal easier but I DID snap one already.
Would like inputs from other peoples experiences here.
Scott C.
The infamous cracked-ticking exhaust manifold issues has been there for years and, while staring at the accessible manifolds, decided its now or never. Pulling the manifolds was not a huge challenge once all suspension stuff is out of the way. Got both out and only the passenger side front port showed a crack similar to what others have posted here. I was expecting worse but for a California-based car, the manifolds are in very good shape and the internal runners were very clean. Got it welded up nice and we're good to go.
Now - one of the studs snapped on the flange going into the drivers side cat. I also had 3 studs back out of the head and one stud snapped at the head
. It took about 1 hour to pull the drivers side manifold and it took 2+ hours to extract that one broken bolt. I tried using extractors and went through all three extractor sizes with no luck. Next, I started drilling the center and moving up one bit size at a time as to not damage the threads. I then used a 8x1.25 tap and tapped the bore in hopes of scoring out the screw threads. Once through, went to 9mm and eventually to 10mm. I'm convinced Toyota sources these studs from Satan directly. I've worked many snapped bolts in the past but this was a BEAST to extract.I have a fresh set of OEM studs/nuts arriving soon with the original plan of swapping all of them out fresh. I'm not double guessing that.
- What if I snap more studs trying to extract them from the head?
- If I reuse the current studs, what if studs snap when retorquing the manifold back down?
I do have Torx E8 socket that I presume would strip the head of the bolt before it would snap off. Arguably there is no rust at the stud or in the head making removal easier but I DID snap one already.
Would like inputs from other peoples experiences here.
Scott C.
