Any photos of this? I know I need to disconnect the driveshaft, and there looks to be 2 tabs that hold the drive unit/axle assy thru the frame. does the gearbox cover just “snap on”?
This engine is kind of a love\hate thing, and well…lets just say I need it apart for repairs[swg]
What exactly are you trying to do? To repalce the wheels/cracked axle gear you don’t have to pull the whole thing apart. The bottom cover on the trucks pops off with the little clips up the sides, and you can pull put the wheelsets that way.
–Randy
I intend to install a new wheel with blind (no) flange, and give the bottom of the frame a “haircut”. The truck swings and gets caught in the (pseudo) frame rail
Even on 22" radius curves the thing derails and I am tired of it.A beautiful model, just runs like CRAP. I have a SD-9 (P2K) that works perfectly around the whole pike. heck even my 4-8-2 mountain and 2-8-4 berk go thru the same area that this SD7 won’t.
I have over a dozen Proto 2000 SD7s and 9s, and all will negotiate 18 inch curves without difficulty. I doubt that making the middle wheel on the axle “blind” will cure what seems to be caused by something else.
As has been said, It is quite easy to just prise off the long flat strip of black plastic on the bottom of each bogie so that you can get access to the wheelsets - slip the head of a small screwdriver under one end and gently ease it under the join, where it can be worked free. Try that, and examine them all individually, as you will then be able to remove each axle easily. I’d go a very long way before attempting what you are proposing, if ever. I doubt very much whether it will cure your problem.
Good luck.
Brian M
If you don’t have one already, get yourself an NMRA gauge and check the gauge of the wheels before you do anything. Also check for wires inside that may be preventing the trucks from swinging fully in all directions.
Are there any other issues with this loco?
as it goes up a 2% curve the wheel sets start to swing (normal) the “suspension”, or lack of, causes the STIFF front axle set to raise up from the track, and it looks as if the “swing” mentioned earlier catches or snags the axle set against the bottom of the frame, binding and flopping it off of the track. I spent 2 entire days rebuilding this particular curve. everything else runs up it fine. AND it is 22" radius.
grinding the bottom flat will insure that there are no hidden snags
I do not have a track gauge. One may be helpful, but honestly, if the wheels are not in gauge/spec they are junk anyways right?? (plus I hate to buy a 5$ gauge and pay 9$ shipping for it)
I have trimmed/cut away most of the snagging details, and honestly, I’m just about ready to toss/part it out.I do this MRR thing for a hobby/enjoyment. fighting with a loco like this kills the fun really quick.
Wheeler,
An NMRA gauge is an ‘investment’. Blinding a driver/milling frames are all ‘guesses’. I have a ‘fleet’ of P2K SD7/9’s and they run fine on 22" radius curves. My ‘guess’ is that you have other issues here. You mention ‘snagging’ - it sounds like your trackwork is in gauge, but the track may be out of ‘tram’(level from side to side). I agree that it is unusual that your steamers run through the same area, and this engine fails to negotiate the trackage.
But like I mentioned, you really need ‘tools’. A NMRA gauge, and a small level are basic tools you should have to diagnose this kind of problem.
Jim Bernier
You can use a simple ruler to find whether or not the track is out of tram. Lay the ruler on the track so that it is in line with the track and get down as close to eye level with it as you can. If one rail rests against the ruler and the other is lower then that indicates that area is out of tram. Many locos will go over these areas with no problem but there’s always that one exception. With me it was a Proto 2000 PA1. It would derail in one particular spot every time just as your SD7 is doing. I did some work on the track in that area and got the rails level with each other and the problem was fixed.
I have a P2K SD7 from the very first run and it had the same derailment problem. To cure it I removed the front truck and file away enough material from the bolster to insure enough side to side and front to back play. This solved the problem forever.