Sometimes you exhaust every reasonable means of taking something apart then result to welding something to it and using a 36inch pipe wrench and 6 lb hammer to break something loose.
These Siamese cylinders for a sliding 3 axle trailer have been laying in my shop for 2 years. It has been in my way most of the time. Too many projects kept taking priority. First I waited a year to get the $1000.00 seal kit for these 2 and 2 other cylinders. When the seals came in they were the wrong ones so another 6 months wait. All the while when ever I thought about it I would spray the gland nuts with penetrating solvents hoping this would make it easier to disassemble the cylinders when the time finally came.
I tried using my Martian adjustable pin spanner even tapped it several times with a hammer to no avail. Tried driving a cylindrical punch in 1 of the pin holes then with a drift and a hammer I hit it hard enough to shear off the end of the punch twice, and this was after heating the end of the cylinder. OK time for the big gun a piece of 3 1/2" pipe tack welded to the face of the nut a 36" pipe wrench on that, almost putting my full weight on the handle of the pipe wrench and hitting the handle of the pipe wrench several times with a 6 lb hammer the tack welds broke once so rewelded and added more weld. This time I added a 3 ft extension to the pipe wrench and my full weight near the end of that hit it a couple hard licks with the hammer and it turned 1 more hit and it was loose