Thanks Andrew - I’m sure i can find one up here in the states, but i would like to see a picture of the one with a nut welded to it as i may try this my self.

Photos of 5 3/4" pre. cups with nuts welded to facilitate removal.
These came with a parts lot I bought a while ago.

Thanks for digging those up and taking the pic. Ill follow up with what ever works on this end.

I have been working on getting the suspected bad prechamber out. Apparently it likes where it resides now and has no desire to vacate.I welded a bolt into the PC hoping i could unscrew it wit impact gun or cheater bar. Nope.
I spent a couple hours today drilling out the threaded end of the PC. The remaining material is very thin. I heated up the threaded area ( again) and tried a breaker/ cheater bar. Nope.

I assume the PC is rusted to the head where there are no threads. My next thought is a truck stop with 1” impact air guns ?

"You've got to use the big guns!"

Hi Team,
on these older engines Cat used an Allen head set screw screwed into the side of the cyl head as an extra security to hold the pre-chambers in place during service.
P/No 4B9746.
Cheers,
Eddie B.

Edb, thanks - another pointed that out and I removed the screw. BUT - i realize now that it too was rusted down to almost nothing on its tip that extended into the prechamber. Tommorw ill run a drill in there and make sure none of it is left against the PC.

Hi Team,
I believe that over time it was found that the screws were not necessary, also there were likely many chambers ruined by people drilling thru the chamber when drilling a new lock position for the screws after the chamber had located in a new position after removal and refitting.

I was taught to cut the screws short at the Dealer back in the day.
Cheers,
Eddie B.

This has been tackled before on here, unfortunately no thread size was mentioned. If my memory is correct it might have been "Steven" on here.