I am working on a Diesel 10 Auto Patrol 1K series engine today.
I believe it is a D4400 engine.
My question is are the precombustion chambers threaded in or pressed in.
I need to remove my old one, the injector uses two studs to clamp the injector in place.
The chamber does have threads at the top but no hex shape at the bottom.

Well, i ended up making a large slide hammer attachment to get it out, and boy was it in bad shape
Chamber number 2A3544
Seal Number 1A2298

Well done Erik, how tight was it in there and I assume you ran some kind of high tensile rod or bolt through the precom nozzle to allow you to pull them out with your slide puller? I need to remove the precoms from my D4400 motor in my D4 2T in the next week, it has the screw in type and I was thinking of using liquid nitrogen inside the precom to try and shrink it slightly to help get them out, looking at some old threads the other day mentioned Florin had those new screw in precoms, not sure about the push in types though.
Regards
Mike

Mike,
Well for the sake of time and not making the effort to build a "proper" tool, i just used some regular steel pipe and fittings and a 22 pound weight.
5 good "slides" and out she came.
I am sure that if the chamber was in better condition this approach would not have worked...but in this case it did the job.

Note:
I blasted the chamber after removal and it was full of many pin head holes, after i locate the parts i will remove the others.

I did run the part number for the chamber thru General Gears cross number reference and came up not showing any part number changes or options.
Cat, Florin and Off Road showed no inventory....
So... the search is on for at least one if not 4 new or good used chambers.
I have one lead on a local supply and will know more after tomorrow.

1) Would it be practical to retro-fit for screw in precoms?
2) are you opposed to installing a later head with screw in chambers
3) could you repair the chamber by tig welding the deepest holes and brazing the rest with a light layer of bronze or 15%Ag (to minimize any contraction)?
4) could a later chamber be modified to fit. Like turning off the threads or brazing/welding an adapter to the end, etc?
5) Erik, you have a GOOD dealer, would they provide a drawing of the press-in chamber?
6) could we make some new ones?

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We need to solve the parts problem before I get into the RD4!

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We haven't seen the 10 autopatrol pics - thank-you

all good questions, i should know more tomorrow and yes i will get some pics of the grader.

Hello Erik if you cant find any, a machine shop by me made some new ones for me on my 75, also the chamber uses a triangle shaped copper gasket on the bottom that I had special made also. See if your Cat parts guy can get you a print on that part number from Peoria. Gary

Mike,
I have had a lot of success removing the threaded chambers using the splined tool and the rattle gun. On the worst ones I applied a little heat with the torch around the threaded area on the head (head removed). The rattle gun seemed to vibrate them loose as the old brute force on the breaker bar just twisted them
off.
Good Luck
Hutch

Thanks Gary, I may end up making some.

I did however find one in Canada but still looking for more.

Here are some pics of the grader, not the best looking of machines but they only made 256 of them in 1937