Not sure if this should be in electroncs...
Picked up a doodlebug at the train swow for $20.
Seems it has something simillar to the P2K "thump of death" that idicates cracked gears.
Anyone know how to disassemble the power truck? I can't find that info anywhere.
Can't see any screws. Unit has DCC socket, and horn hook coupler. Hmmm...
Still looking through 58 pages of posts on this forum, but 90% are either "remove shell" (figured that out- wasn't fun), "is there a prototype", or "Walthers or Bachmann".
Any Help appreciated!!
I know this is probably no help at all, but mine has developed the same thumping problem. I just put it back on the shelf and haven't tried to open it up and see what the cause might be because I don't run it enough to fuss with it.
Even if you could get it opened up and discover that it has a cracked gear, I seriously doubt that a replacement would be available from anywhere because this model is too old.
Purchases at a train show are a case of "you get what you pay for" and there's absolutely no warranty on anything. By now the vendor who sold it is long gone.
The shell is removable, using care. I believe you gently pry the bottom of the shell away from the bottom and slide in a tooth pick or something similar between the shell and the frame. After inserting a couple of tooth picks, you should be able to lift the shell off the frame. TAKE CARE AS I DO NOT KNOW IF ANY WIRING BETWEEN THE SHELL AND FRAME.
Check out this site
http://www.bachmanntrains.com/home-usa/board/index.php
Do a search on your question and you should find the official answer'
You can take the shell off by gently pulling out the lower edge of the sides, beware there are many pressure points along each side. With patience the shell can be pulled up and off. There are no wires attachinf to the shell. The thumping is most probably because the front (power) truck has come out of the cast guides (at the top of the power truck. With care you can gently rotate the truck back into place - provided that the casting has not been broken. I have had this problem and performed the above recovery procedure and had many hours of subsequent trouble free running. Good luck.
Bachmann is reissuing the doodlebug, so its possible that you will be able to get replacement parts.
Alex
Thanks for the replies, but none address the power truck disassembly issue.
I figured this would be a project, and research indicates most were shipped dry or underlubed, and wear causes the mechanism to loosen, potentially causing the condition.
I was hoping to see if I could shim the bishings, or if the gear really is cracked.
I figured out how to remove the shell, and discovered it had been glued (they even got a bit on the windshield). The U joint for the motor was shoved all the way back, causing the motor to spin without turning the gear tower- that's fixed now, too. The press fit of the power truck to the chassis is OK, although I strongly dislike that design.
What I really need is help getting the power truck apart. I can't even figure out how to get the truck sideframes off. I've heard the power truck is the same as the 44 tonner, but it doesn't look like the pix I've seen eleswhere on the web.
I'm not positive, on this but if you remove the gear clip on the top, and pull the truck out from the bottom. If there are any screws on the truck remove them, although I can't recall if there are any or not. There is probably a bottom plate on the gear box too which should be removed. The truck/gear tower should come apart in two halve, and I think the sideframes are held on by the bottom plate.
Thanks for your interest in helping me.
The problem is that I can't see any way to get the bottom cover off.
Bothfront and back are free, and I can slip a fingernail under them, it seems like something is holing it only in the middle. If feels like if I continue prying, it will break.
There are no screws anywhere.
The side frames also appear to want to break if I try prying them straight off.
I'd love to hear feom someone who can say for sure "pry here", or "remove the side frames first".
I also can't see how something as far down as the bottom cover could hold the two halves of the tower together all the way to the top, a distance of about an inch, with the worm at the very top.
Well I found it.
There is a clip coming up from the cover plate that looks like it is part of the electrical contact.
it is like a very thin plate on oth sides of the tower that has a slot which fits around a bright bronze colored tab about 1/32' thick and 5/8 long.
On the outside of this clip, just below the slit, is the very thin bronze strip that has the wire soldered to it.
I guess the gear tower is a press fit, and the clip on the cover/side frame assebly just reinforces it while also holding the axles in and sideframes.
had I continued either prying the cover or the side frame, it would surely have broken.
Anyway, the gears on both axles are indeed cracked.
I will try Bachmann for parts. I find it odd that they list only about a dozen parts a available, mostly Thomas the tank engine faces.
BTW, the drive truck is definately NOT the same as my 44 ton.
Perhaps the whellset and gear are, though.
Thaks for everyone's help.
My Doodlebug also has a cracked gear. I was able to fix it by taking the gear off, shrinking that part of the axle with a file until it was a slip-fit for the gear, and then super-gluing the gear back on. I haven't had a problem since. Replacement gears would be far easier, though, so if you can get some from Bachmann, it'll be an easy fix.
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i realise this is an old thread but there doesn't seem to be much information about the bachmann HO doodlebug.
from anyone who has disassembled the truck, i wonder whether it can be regauged?
regards, ben
Regauged as in adjusting the wheels to be at the proper distance on their axles? All you need is an NMRA standards gauge to check them. The wheels can be adjusted by hand or with a wheel puller if they're out of gauge.