Could be bolts into nuts or bolts into a threaded hole in the flange. Either way if your pulling it apart just grind both sides clean and then install new bolts and nuts, along with a new flange gasket.
Hi, Mid-way down the car, at the tail end of the catalytic converter, there are flanges and 3 bolts on my '95 Saturn SW1. If they were nuts at some point, I couldn't tell you, but whatever's left has to come off, because the oil pan is coming out. Just curious, what do you use when replacing these bits of old fasteners?
TIA -
Mark
Hi, As I get more of the rust off, it looks like bolts that run through from the converter side, and on the back side, the flange itself is threaded to receive the bolts. Those don't look like nuts or ordinary bolts - the bolts themselves taper to really twiggy ends (all 3).
So it looks like I might be supposed to try to save the threaded (receiving) flange, and maybe just cut the bolt heads off and unscrew and replace the bolts, but those bolts also look pretty well rusted/fastened to the receiving flange threads. One of the bolt heads is also impossible to reach with a power tool (the one on top).
- Mark
Well, I went ahead and did what I could, which is cutting everything all off.
Now according to the parts guy at Saturn, and I was guessing the same, this was supposed to be nuts and bolts - it isn't. The flange on the converter side has bolts welded right in there, it appears. I have cut the heads and tails off, and I am going to have to drill out those holes.
Right now, I don't have drill bits/drill that can do it. Perhapos I can find a shop with a drill that can?
Cheers -
Mark
Take it to a muffler shop and have them torch it off, and then tape/wire it together for the trip home.
If the bolts were welded to the flange, they were probably welded at the heads. Try grinding the heads off right down to the flange with a die grinder or 4" angle grinder if you have one and then drive the shanks out with a round punch and BFH. If the welder was really good and got lots of penetration you may end up having to drill though. Get NEW HSS drill bits and have a friend spray some oil on the bit while you're drilling. low-ish speed, a high torque (1/2" chuck) drill, and a reasonable amount of pressure seems to work best with hardened bolts. Drill bit may last only a couple of bolts. Drill a small pilot hole first and then go to the through hole size. replace bolts with stainless ones with lots of anti-seize :) Dressing the flange (I assume it's flat) with a flat file before installing a new gasket will help it seal better.
good luck
nate
Mark G. Meyers wrote:
Nate, Sounds to me like you're speaking from experience on all counts. These bolts were welded in pretty nicely, because I can't find the place where the head leaves off and the flange begins. BFH- I'll remember that!
Thanks - Mark
I'm used to working on cars 40 years older than your Saturn, so I am no stranger to drilling out busted bolts :(
I can, however, state that I have successfully drilled out bolts in blind holes using a hand drill without having to use a Helicoil.
I guess I should put that on my resume :)
nate
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