# 312AC roach breakdown



## flyernut (Oct 31, 2010)

Here's my new to me 312AC. I'll do a quick break-down.


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## flyernut (Oct 31, 2010)

Boiler front removed along with the smoke stack. The wires to the head-light socket were not attached to the boiler front. Next came the cow-catcher


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## flyernut (Oct 31, 2010)

Next the steam chest.


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## flyernut (Oct 31, 2010)

Linkages removed from both sides.


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## flyernut (Oct 31, 2010)

Chassis separated






from the boiler shell.


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## flyernut (Oct 31, 2010)

Hand-rails removed, and chassis stripped.


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## flyernut (Oct 31, 2010)

Here's what I found, and did.... De-greased the entire chassis/oil-pan using CRC Lectra-Motive parts cleaner. This stuff is great! It won't harm plastic, and does a great job on e-units......After getting it all cleaned, I noticed the brass stud on the middle wheel rim was not in all the way, and after further examine, I saw it was bent. I pulled the whell and put a NOS wheel/stud on, and re-quartered the wheel set. Here's how I re-quarter....I put the linkage that connects the 3 wheels sets on the opposite wheel sets, and screw it on using the large screws that hold on the linkage. These larger head screws will tighten up nicely and hold the wheel set and linkage in place without damage. I then flip the chassis over and eye-ball the correct position for the middle wheel. I then press on the wheel, and check for quartering. I then added new brushes, new brush springs, re-faced the armature, and used the cleaning fluid as described earlier, and squirted it on the brush holder. After that, I run a piece of rolled up sandpaper and scrub out the brass brass tubes. The brushes have to move freely to insure the correct pressure is applied by the brush springs. Another squirt, and let it dry. This motor also was missing the thrust washers, so I added a new one.Smoke unit was fine, and a simple clean-up with some grease inside the piston cylinder was all that was needed. During initial check as to run-ability, the armature would not turn over. After dis-assembly, I found the smoke gear was frozen tight with old grease and oil. It's now clear and movable. I assembled the entire chassis and did a run in and she runs great, a very fast chassis. I polished all the linkages, and had to straighten out a few pieces that were bent. I polished the hand-rails using 2000 grit wet/dry paper, and they shine. A final re-assembly, minus the boiler front, and she's looking good, and running great. I won't bother people with the final assembly of the boiler front. I'll do the tender next.


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## flyernut (Oct 31, 2010)

Forgot to add the final picture.


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## cramden (Oct 13, 2015)

Thanks for the follow along rebuilds that you do, they are much appreciated by me. You always do a great job saving these engines and such. I have used the same trick with the linkage on the opposite side when a wheel needed repairing or replacing. There are a few complete tenders and shells on the bay, they show up frequently. Never understood people that strip down engines and think they'll get more money selling parts piecemeal. Just my opinion, that and two bucks will get you a coffee.


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## flyernut (Oct 31, 2010)

cramden said:


> Thanks for the follow along rebuilds that you do, they are much appreciated by me. You always do a great job saving these engines and such. I have used the same trick with the linkage on the opposite side when a wheel needed repairing or replacing. There are a few complete tenders and shells on the bay, they show up frequently. Never understood people that strip down engines and think they'll get more money selling parts piecemeal. Just my opinion, that and two bucks will get you a coffee.


Thanks for the kind words.. I saw quite a few shells on ebay, but all of them are for the SIT chassis.. They all have that big obnoxious hole on top of the coal pile, and the big, gaping hole in the front of the tender.. Not for me, I'll wait it out,lol...


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## AFnew2 (Aug 28, 2016)

*Good info*

Wasn't sure about the quartering...:smilie_daumenpos:


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## AmFlyer (Mar 16, 2012)

Flyernut is really good at these rebuilds.


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## cramden (Oct 13, 2015)

Was the half-circle tube that sits over the boiler top in front of the stack missing or did you not install it yet?


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## flyernut (Oct 31, 2010)

cramden said:


> Was the half-circle tube that sits over the boiler top in front of the stack missing or did you not install it yet?


That one is missing, I'll have to make one up.


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## cramden (Oct 13, 2015)

That one shouldn't be that difficult. I lost one years ago and was sure it was on the engine when purchased and found it about two years later in one of my plastic containers that I store trains in.


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## flyernut (Oct 31, 2010)

The roach is finished, and she hauls a++!. I still have to get a tender shell for it, but it's all done. New brushes, new brush springs, re-faced armature, added new thrust washers, replaced bent stud on blind driver, re-quartered the drive wheels,














straightened bent linkages, de-greased complete chassis, un-froze the smoke gear, re-greased, re-oil, added new head-light, constructed new wire harness, polished reverse unit drum, new upper and lower fingers, polished tender wheels, and cursed a little, but it done... Now for the 302AC that's sitting in the wings. But not tonight, I drove to my little sis's house today, painted her bathroom ceiling, removed all the floor moldings, and did some furniture moves, fixed her garage opened, and fought a deadly fight with a 3 foot snake.. Yep, I have a huge "S" on my chest,lol!!!!!


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## cramden (Oct 13, 2015)

Nice. Do you use a Dremel with a brass wheel or some type of polishing compound on the brass pick up wheels. I've always liked the brass wheels over the metal ones.


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## flyernut (Oct 31, 2010)

cramden said:


> Nice. Do you use a Dremel with a brass wheel or some type of polishing compound on the brass pick up wheels. I've always liked the brass wheels over the metal ones.


I use the smaller roller for polishing, and some rogue.


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## cramden (Oct 13, 2015)

Thanks, I haven't tried that but I've used rogue on the tail of the 663. It really works great to polish that piece up.


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