1981 280zx 5 speed

[Dave WM]

I decided to go a head at get the black pinion gear for the speedo, I was going to swap with the old 4 speed but that seemed like more work than needed, as I would like be ready to go when I get it out.

Next snag, removing the bolts at the bottom of the exhaust manifold so I can swing the exhaust pipe out of the way. I have been hitting them for days with PB blaster, tried a box wrench, not even a budge, that was just from the top to see if anything would be easy.

I have been researching how to get them off. I think the best solution IF I can get it to fit would be a nut splitter. After that a oxy/ace torch and heat would be next (some show wax being used like flux on the hot parts). I do have an electric impact wrench. I can get a torch setup for around 200$ seems like a handy thing to have anyway.

[Mark Maras]

 Those studs can be the worst part of pulling a trans. The nut splitter is a good idea. Let us know how it works. I broke two studs the first time I pulled a trans. I had to get it back together for the Mon. morning work run so I drilled out the broken studs and through bolted the flanges. Don't forget the Never-Seize thread lube on all the threads.

[Patcon]

Do they not make a copper exhaust nut or a copper coated nut that would work for our cars. Correct thread and pitch... Would eliminate some of the broken studs issues I believe...

[Dave WM]

I went out and looked at it again, will get some pic to show rust and nut status. I sure seems like there is good access all the way around for a nut splitter. I will go to some stores ands shop around to see what is out there.

[Dave WM]

here are some pics, maybe not too rusted after all?

[Mark Maras]

39 minutes ago, Patcon said:

Do they not make a copper exhaust nut or a copper coated nut that would work for our cars. Correct thread and pitch... Would eliminate some of the broken studs issues I believe...

 You should be able to source brass nuts from a local bolt and fastener company. I Googled metric brass nuts. Lots of sources there too. Stainless steel nuts might be an option too. 

[Zed Head]

They don't look terrible.  The thing about rust is that it expands when it forms.  It's not really two parts rusted together it's rust filling the gap between two parts.  At least you only have one part rusting.  Those brass nuts will probably expand quite a bit with a torch on them, and they have good solid flats to fit a wrench on.  I used stacked extensions and a breaker bar from underneath on mine, with a good socket, not a cheap loose weak socket.  You get one good shot, prepare well.

It's a dice roll, still.

[Zed Head]

You might find also that it only moves when it's hot.  I've had that happen on several parts.  Heat it, turn it, heat it, turn it.  I've also had the stud come out with the nut attached.  I actually re-used it as a bolt, it was the only one I had at the time.

[Dave WM]

so I am guessing my little propane torch used for soldering copper plumbing is not man enough for the job? oxy/acetylene is the only way to go?

[Zed Head]

I used MAPP but if I had oxy-acetylene I would have used it.  It's a lot faster and more concentrated.

[Zed Head]

I should say though, that even with heat and PB Blaster, I still broke one.  That's why the nut-buster/cracker sounds like a good idea.  Same reason I go directly to Vise-Grips on the brake fittings.  Shifting the odds.

[Dave WM]

digging around I find nuts for sale at MSA 7$ each, while zcardepot has nuts and studs all 3 for 13$. Looking closely it looks like the 13$ uses much shorter nuts, that is if the pics are accurate. Need to source these if I go the nut splitter route.

Found a local nissan dealr for 4$ each on those nuts so went that route.

 

Edited May 5, 2016 by Dave WM