Tricks to O2 Sensor Stud/Nut Removal

[Scamper]

So I gets me some new sensors from Dan, and go to put them on the truck this morning. Number 1 is off and new one on in just a few squirts of PB, couple of tugs on the wrench, a quick reassembly with antiseize and click of the torque wrench.

Head to the Number 2 (which by the way, is nicely hidden from view by that shield--makes it hard to get at those nuts). Find that the nuts are either some strage shape I don't recognize, or they're severely buggered up by some previous mechanic, even though they never been replaced and I've owned the truck since new... :'(

Tried for over half an hour to get them off without screwing them up any further...I think there has to be some trick to this--at least I'm hoping. Otherwise, I bring the new sensor to the dealer and tell them I just want them to replace it. I hate the idea of that, but if I can't get those nuts off some way, I'll have no choice...

Any ideas fellas? (please don't tell me to weld a bolt to them...no room and that would really fauwk it up the way I weld in tight spots!)

Tom

 

[Cruiserdrew]

Not sure about the shape, but they do get rusty. It may be time for the "hot wrench". Heat the nuts with a MAPP gas torch until they are very, very, hot and try then. Any exhaust shop should be able to handle this if you don't wish to hit the dealer.

 

[Scamper]

The problem is that there's nothing to grab onto--someone (?) at some time must have seriously worked those nuts over with the wrong wrench because I can't get a wrench to grab onto anything. Suppose I could just take it to some shop, but they're likely to tell me I need a new muffler too, bless their hearts...

 

[landtank]

I remember having a tough time with mine but I did get them off. You might try a dremel tool with a cutting wheel to slice the nut and then work on the studs as they will need replacing.

 

[lovetoski]

Would a nut-splitter work?

 

[Scamper]

A nut splitter won't work on the #2 becuase of the cute little shield they put over it, limiting access. It might work on #1, but I was able to get those off pretty easy.

I think Rick's idea of the dremmel is best, though I'll have to get some studs before I do that.

 

[IdahoDoug]

Seems like there was an O2 sensor service bulletin on the 80. Mine had them replaced free under this campaign, and if yours was also part of it, then there may have been a boneheaded mechanic in there at some point when it was in for something else.

DougM

 

[landtoy80]

How do you replace stud?
I am sure I will brake the stud off when I try to remove the nut.

 

[landtank]

Once the O2 sensor is out of there then you can freely it it with heat if you have to. But I'd bet that the stud will come out pretty easy once the nut is off.

 

[cruiserdan]

[quote author=IdahoDoug link=board=2;threadid=14964;start=msg141019#msg141019 date=1082268813]
Seems like there was an O2 sensor service bulletin on the 80. Mine had them replaced free under this campaign, and if yours was also part of it, then there may have been a boneheaded mechanic in there at some point when it was in for something else.

DougM
[/quote]

The S02 campaign aplies to 93-94 only (side-by-side cats).

The nuts on the rear sensor are the same as the front. Have you tried a six point?

 

[Rich]

Sand is your ticket. When I encounter a problem with the wrenches or sockets getting a grip I apply a very fine sand (intended for sanblasting sparkplugs) to the socket.

 

[Wayne]

I'm interested in your fix to this problem....... I have exactly the same problem ???. The nuts appear to have rusted into a small size and no socket will fit them correctly :-\. I'm also afraid of twisting off the studs if I get too aggressive :'(. Be sure and lets us know what finally works.

Wayne S

 

[Scamper]

Have not tried a six-point yet...but can't really see that even that would get any purchase on these nuts. They're really nicely rounded over. I've considered ways of just removing the entire nut/stud combo--I could then just replace the combo with a bolt of the proper size, but I still have to get the dman things off. I'm spending some time 'thinin on this one before I do something I regret.

Tom

 

[Rich]

Not using a six point socket or wrench is counterproductive. Heat the nuts as hot as possible with a mapp torch or an acetylene torch. Use good penetrating oil repeatedly, over a number of days if necessary. If the studs break then remove muffler, drill, and retap.

 

[landtank]

Since you're replacing the sensors a torch is ok but I'm not sure about using one on a good sensor. I needed to salvage mine as I was just replacing the exhaust. IIRC I sawzalled that section of pipe out so I could work on it better. Not much help with your situation though.

 

[landtoy80]

Sears has a new nut remover. It looks like a socket but it is tappered with groves that grab a rounded nut.

 

[thelal]

I had the same problem and I ended up breaking off my stud (oops). It now is held in place via a wire clamp. Will get around to replacing it probably when I get a new exhaust.
The funny shape is due to rust and looks nothing like any nut every put on.
Good luck with the heat and Dremel treatment.

 

[Scamper]

This is real damage to the nut and is certainly not caused by rust. A six point would not help IMO becuase there are zero points left--barely a trace of something to grab. Some goober really did a job on them (or they are special OEM "never get 'em off" nuts).

Kurt: I was hoping there was some magic tool that would help me--thanks for the tip on Sears.

Tom

 

[Koffer]

I've been looking into replacing of the o2 on the 96 . I ordered them from Cdan back in Oct but havent gotten to it since Its mine and its always easier to get the parts
Today I was out at a car show and swap meet with cruise4070. I bought some reg shop stuff like hose clamps and other goodies.
When we got done Cruise4070, my wife and i went out to get a bite and I could here a rattle under the truck like a broken exhaust sheild . oh well I fix it when I get home sometime .
didnt get too far (1/4 mile or less)as the front O2 sensor has lost both nuts and now has blowen out of the hole
Im glad I got hose clamps as I popped it back into the hole and did my best getto fab with a couple of clamps I had bought .
The treads are fine on both studs so if I get lucky maybe the rear one will fall out so all I got to do is just pop in the new ones and I'll be golden

 

[Rich]

If you use a six point socket with sand I'll wager that you will get enough torque to either remove the nut or break the stud. Get the nut and socket wet if necessary to get enough sand to adhere. The sand makes a huge difference. Compared to a 12 point socket a 6 point also makes a huge difference.