Kris9884

iTrader: (7)

So I'm replacing the cats and o2 sensors and ran into a problem. I noticed while removing the cat there was a bent stud and the nut wasn't threaded on all the way, no more than halfway but it wasn't leaking at all before. Went to install the new cat on the driver side and just like before the nut only threads on about a half inch but now it DOES leak, pretty badly. Is there any way to remove this stud without taking the whole damn manifold off?? Or is there a workaround? Can I get some high temp rated washers and stack them up to the bend? The other 2 nuts bolt up and are torqued to spec and passenger side is all bolted back up and ready to go :/

Ali SC3

iTrader: (10)

on the end of all the studs is like a star pattern and you can get a small socket to fit over it I forget what size it is... like a 7mm or something I Can't remember but most of the time it just gets stripped and doesn't work, so what I do to remove them is I clamp onto that end part (not the threads) with the largest vice grips in my tool kit, and then a good turn will usually break the stud free so you can back it out, or tap the vice grip with like a rubber mallet if you are having trouble breaking them loose.

when they look old and rusty I pretty much always use the vice grips to get them off. spraying it with PB blaster around 30 minutes before will help a ton, trust me its worth its weight in gold. Otherwise you can try heating up the stud/flange with a torch and try and break it free as its cooling down, depends how well its stuck in there.

don't grind or cut it off, then you will have to drill it out and those things are a tough metal, you will be there all day.

oh and how that happens in the first place is someone removed and put the nut back on without cleaning the bolt. it gets rusty and then when you back out the nut it messes up the threads.
IF you want to save them and avoid replacing, if you see rusty or dirty threads, get a drill with a wire brush attachment and go over the bolts a few times to clean it up, and use something like wd40 to lubricate it, then you would have a shot at re-suing it. even at the point you are at, sometimes cleaning it will allow it to catch the threads and not get stuck halfway if its not too bad yet.

Kris9884

iTrader: (7)

Ah gotcha, thanks! It was pretty dark under there so I didn't notice a star pattern, but as you said, it's likely a lost cause. I tried getting 2 nuts on there to tighten against each other to back it out but there isn't enough thread. I drenched it in PB blaster last night and I'll do it again before I attempt the removal. If that doesn't work, I've bumped into numerous situations where I could use a torch and never got one, I think I'll finally go grab one at Harbor Freight and see if a red hot flange will let it go any easier. Wish me luck.

Edit: Any idea what the thread pitch and width is for a replacement stud? I'm fairly certain ACE or Fastenal will have something for me, I doubt Lexus has them on hand..

Ali SC3

iTrader: (10)

you should be able to get it off with a decent set of vice grips, its my preferred method and hasn't let me down yet not even on my old 1985 toyota 22r motor which there was literally more rust than studs left...

intake bolts are M8x1.25, exhaust bolts are usually m10x1.25
Ace has the bolts and nuts, but not always the studs. sometimes Its not a bad idea to just replace the exhaust studs with a regular bolt and nut so in the future you can just cut them off, but it makes it harder to line it up without the studs. I think I have been under too many toyota's...

Kris9884

iTrader: (7)

Thanks

Those old Toyota pickups, Celicas, 4Runners etc just seem to be made of rust, I cant say I have seen a pre '85 pickup in even ok condition lol.