corvettedreamin

Team Corvette (we're all in this together, right?)

I'm replacing the mufflers on my '82 because, well, one just got ate through by rust at the junction of the tailpipe and muffler. So I decided just to replace both mufflers and tailpipes.

Having seen the exhaust under the car many times, I thought, "how hard can this be?"

Guess what? My car (with 116k miles) has either a) the stock exhaust or b) a GM replacement that looks just like the stock exhaust. I've had it for the last 27k miles so I suspect it's original (GM part numbers on the mufflers.)

So I undo the clamps (4) with air tools and eventually vice grips (cringe) on one uncooperative nut. Everything's loose but guess what... the mufflers still won't come loose. I cut one off close to the muffler/exhuast pipe junction with a cut off tool. The other is still connected. It seems my "biggest" problem is the junction between the rear Y-pipe and the short (10") connecting pipes that go to the muffler.

Any tips on how to separate these pipes? I hate the idea of getting "adapters" to join everything together but I'll be damned if these things don't seem "glued" (although they don't appear to be welded) together. I could heat up the extension pipe with a torch... that seems feasible. Or I could cut a slot in it and attempt to seaparate it from the y-pipe. If at all possible I'd like to leave the Y-pipe in tact. I also have a pipe expander I'm considering using if I cut off all but the last couple of inches of the extension pipe AND cutting a slot in it. The thought being the slot plus the expander will separate the extension pipe from the Y-pipe. Yes, it is more time consuming than an adapter.

The funny thing was that when I started the car up with the left muffler disconnected it blew "chunks" from the unmuffled exhaust pipe. Makes me wonder how bad the catalytic converter is now. Again, 116k miles. I'm thinking about working my way forward to the manifold Y-pipe and replacing everything. Although for cost reasons I'd prefer not to since there are no holes in them.

Thanks in advance,
Jerry

ManFromEagle

That's a tip I'd like to hear also. I've tried to seperate the pipes and it seems almost near impossible.

jcswm

I'll bet a Muffler shop would cut it off for $10.00 or so.... that old It's going to need heat or an air hammer!!!

Jughead

There's a reason the muffler shops usually want to replace the entire exhaust. I found it almost impossible to replace or remove an old rusted together exhaust pipe. Not much better than a rusted in place bolt. If you do get them separated, there's a good chance that it won't seal properly.

BerniesVette

I believe that Virginia has state inspections so I would buy a performance cat convertor and have a muffler shop install an aluminized exhaust system with good sounding performance mufflers. Unless you want to spend more; go with a mandrel bent exhaust system. There are so many good exhaust system options out there your budget would be the deciding factor. Old exhausts just aren't worth the effort to try to salvage. Good luck with whatever you decide.

corvettedreamin

Thanks guys... but no where in there did I hear, "cut the thingamajig with a whatchamacallit and it'll come right apart."

Now I feel a challenge.

The rest of the system is basically OK, not even rusted. Even the pipes that are "stuck" aren't rusted together. Just 23 years worth of fusing. It sounds like cutting the Y-pipe or the exhaust pipe is in order and simply adding an adapter. It means a couple of extra clamps but at least it will work. I'm trying to resist going to a muffler shop and having them do the "weld on long pipe" option.

On the other hand, replacing the cat with a new one as well as the rear Y-pipe almost seems like a worthwhile upgrade (hey, every 23 years doesn't seem that bad.) But I'm in the middle of several repairs that are costing around $2000 and I'd like to keep the mandatory labor to a minimum. Yes, I'm in denial.

Incidentally, getting the 23 year old rusted clamps apart was no problem using Rust Eater and PB Blaster and an impact wrench. Only one stuck and a pipe wrench, vise grips, and patience got that one off. Tomorrow I'll start with a torch and die grinder and/or dremel to cut off the extension pipe that goes to the muffler. I also have a BFH handy for persuasion. I already have the mufflers (Dynomax Super Turbo) with the tail pipe and extension pipe that connects the muffler to the Y-pipe so I'd like to get away with using what I have.

Jerry (no, my nickname isn't Bubba.)

MYBAD79

Most of these exhaust clamps cause a circumferential groove, then let it rust for a few years and you'll never get it apart.... been there, done it...
You can save the Y-pipe - cut carefully only the outer pipe (this will be the muffler's pipe that is slipped over the Y-pipe), cut it axially, not circumferentially and then bend the outer pipe back.

This takes some patience and time, that is why muffler shops replace the entire system.... well, if you pay them for removing it carefully it would probably be more expensive than the replacement...

But then again, after 23 years it's time for a new catalyc converter and some stainless exhaust system, don't you agree ???

corvettedreamin

Hey, in 23 years "most" of this car still looks like new. But yeah, a new cat is in order. I was going to use the neighbor's but then I thought the heat would just melt the fur against the floor of the car and then it would just stink. . .

Your tip was exactly what I was going to try. I don't mind spending the time (I have four days off and don't need the car on Monday.)

This car still passes VA safety and emissions inspections with flying colors. Perhaps by the time I'm done it won't!

Thanks,
Jerry

MYBAD79

Hey, just flange a "test pipe" in there and store the new converter... that way you'll have a good catalyc converter everytime you need it for emission tests... i've done that before, unless you drop it the converter lasts forever...

corvettedreamin

Your name isn't Bubba by chance, is it?

Jughead

I forgot about the groove. That's true.

That's not a "Bubba", Bubba would have used flexible pipe or pipe from an S-10.

corvettedreamin

I've got a pipe expander that will "fix" the groove, no worries there. But thanks for blowing my idea of using flex pipe out of the water... now I'll just have to come up with something else. Maybe 3 or 4 adapters and 6 or 8 clamps. . .