Downpipe removal/install question

[izak]

How hard is it to remove (and maybe reinstall if things dont work out) the stock downpipe? I've loosened the bolts at the soot trap and have the airbox removed; I'm just looking at that little collar contraption holding it on the manifold and wondering how that thing works. Is it a can of worms to get it re-positioned again and tightened?

I recently purchased a flowmaster downpipe and crossover tube and had them ceramic coated. Itching to install them but it keeps raining.

[Turbine Doc]

Not too bad just don't lose the nut, ratcheting box wrench works well on them.

[Dan Nicholas]

Hi Izak,

It's easy to get the downpipe on and off the turbo. Just loosen the pressure clamp around the turbo outlet, give the pipe a "whack". The hard part is fumbing around to get the new one (or old one I guess) in position. Not much room there. The downpipe is a pretty easy install. FYI, I had to loosen all the mount clamps on the rest of the exhaust system (muffler, tail pipe...) and push it backwards to get some room to work.

I gave the crossover pipe to a muffler shop. I didn't have torches or welder or the patience to deal with seized manifold bolts.

[MTTwister]

IZAK - I did mine recently - replaced downpipe and gutted the cat - Remove the airbox to get some elbow room. The nut doesn't have to come off the clamp - just undo it enough to slip it up. I had to take my crossover pipe out to get the cat out to gut it, and I instaleed the new downpipe before I put the crossover back in - had a lot more working room. Guess I was fortunate I didn't have any seized crossover bolts, although I did have to re-chase threads on about 2 of the 6 bolts.
To hold my downpipe in place - I ran bailing twine from the bottom 2 holes of the 'cat flnge' up to a 1x laying across the engine/fender. 2 second string was wrapped around the plug used for a thermocouple probe, and crisscrossed around the pipe to keep the top up, in, and handy. A deep well 1/4 socket and a stubby extension will give you enough clearance to re-snug the bolt on the exhaust-pipe clamp while you keep it in place with your left hand. Lots turning on that nut before it snugs-up.

I thought the downpipe would be a lot tougher than it was, managed to make it a one man operation. Didn't have to cuss at it too much either, as I recall. smile.gif

[izak]

Thanks for the tips, i think i used all of them!

I had to undo all the mounts like Dan said to get everything out of the way, and I went one better on MTTwister, taking out the airbox and then unhooking the coolant tank and draping it over the top of the engine. Lots of room up top then. Ended up using more MTTwister's advice and removing the crossover tube. Should have just bit the bullet and done all of this prep before hand instead of stopping and starting. I also left everything loose and tightened it one part at a time while checking clearances. My crossover bolts squeaked a little but came out fine. I wire brushed them and put a little anti-sieze on them for the reinstall.

The flowmaster kit went in fine eventhough it doesnt explicitly say Tahoe/Suburban. One thing I would suggest to the next guy - when you get your old crossover tube out USE IT TO CHECK THE GAP BETWEEN MANIFOLD TUBES on your new crossover. Mine were just 1/8 to 1/4" narrower and it would have been easier to stick something in each and coerce 1/4" bend before I put them on. I eventually persuaded the bolts to line up and start, but I may end up having to redo that part.

The ceramic coated parts look nifty. Now it's time for a test drive!