Exhaust Riser Replacement - Bottom Nut Leverage

[Stu Jackson]

In removing the riser there are three studs and nuts.  The top two are accessible, the bottom one is more difficult.  Almost impossible.

For those of you who have suggested a 9/16 inch box wrench (14 mm works fine, too), what did you use for leverage to get that darned bottom nut off.

I've sprayed it with PB Blaster and will return tomorrow, but the first efforts were not heartwarming.  I'll keep at it, but any ideas would be most welcomed.

[Ron Hill]

Stu : I've never had a problem with that bottom nut.  Think I've had it off 3 or 4 times.  You might try a short piece of pipe on you ratchet.
Good Luck, maybe the liquid wrench worked overnight.

[Steve McGill]

Stu,

I completed my riser replacement from CY this past winter.

For all 3 nuts I used a 5/8” socket. On the bottom nut I used a 5-6” extension on a 3/8” socket wrench. This allowed me just enough clearance with the diameter of the extension and the socket wrench to clear the first upward joint on the riser. I was able to use this method for both the removal of the old and the install of the new riser.

Additionally I used BP on 3 separate occasions 3-5 days apart.

Good luck,

Steve

[Stu Jackson]

Steve,

How'd ya get a socket on that mother?  In an earlier series of posts on this subject, I remember that Randy Davidson (I think it was) said that he needed to use a box end to get it on the nut.  That's been my experience, so to get a socket on it (9/16" or 14 mm - barely - work) would require pounding it on with just a tad of HOPE to get it to turn because of the metal surrounding the nut and stud.  I'm willing to try pounding a socket on it with lotsa lubrication on the outside, but one of my next thoughts was to use a Dremel to shave the nut off the stud.

It's been a real fun day standing on my head down there!   

[Steve McGill]

I had to remove the HX bracket from the engine (2 bolts) this allowed the entire HX unit
to drop down and  provide clearance  to the lower bolt .

I was able to put the socket on the lower nut with just hand pressure.
Below is picture of my flange and the lower nut prio to removal, sounds like I may have much
more clearance then yourself.

Steve

[Stu Jackson]

Steve, thanks.  That picture looks eerily familiar, since it was in your earlier post which I printed out and have onboard.  Your bottom nut seems to have way more clearance than mine does.  Odd, since one would think the flanges would be the same.  The HX is old news, took that off first to be able to get back there.  It's really too bad they didn't build the flange so the bottom nut would have the same access as the top nuts.   I'll give it a go today with more PBB, try the socket route, then heat, then I might have to whack the nut off. I'm taking pictures, but the camera is on the boat.  Hmm, how about a movie??? The dialog would have to be blanked out!

Thurs. night update - It's OUT!.  A friend, Jim, came by and with some additional leverage from a screwdriver on the top of the HX bracket pushing up on the bottom of the wrench facing to starboard underneath the flange with just a gnat's eyebrow worth of clearance, it broke free.  Roll the "Chariots of Fire" music and a sunrise!!!  Thanks, guys.