# dd40 info



## matt (Jan 24, 2010)

I recently bought a Bachmann Spectrum dd40 and during testing I noticed that it struggled when going into the first curve on my test track. My test track has 22radius by the way. So I took the shell off to look inside. After I took the shell off, I put it back onto the track with four cars behind it and what I saw was the drive shaft spinning where it meets the worm gear. Im hoping someone could shed some light on this or should i just send it back?


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## TulsaFlyer (Sep 21, 2009)

If it's new, I wouldn't even mess with it....send it back to them for a replacement.


Jody


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## mr_x_ite_ment (Jun 22, 2009)

Matt...I think it is as simple as the DD40 might just be too long of a train for a 22" radius. I recently bought a Bachmann Spectrum Dash 8, and it will slow down slightly in my 22" radius as well. Does it seem to perform all right on the straight track?

Chad


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## tjcruiser (Jan 10, 2010)

Yeah, but if the "drive shaft is spinning where it meets the worm gear" ... that should be a rigid attachment, right? I'd check with Bachmann, if you can.


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## matt (Jan 24, 2010)

mr_x_ite_ment said:


> Matt...I think it is as simple as the DD40 might just be too long of a train for a 22" radius. I recently bought a Bachmann Spectrum Dash 8, and it will slow down slightly in my 22" radius as well. Does it seem to perform all right on the straight track?
> 
> Chad


It doesnt move at all on a straight away with just four cars on it. I can see the drive shaft spinning where it meets the worm gear.


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## mr_x_ite_ment (Jun 22, 2009)

Matt...I agree with tj on this one. I once bought a Bachmann DC loco for only $29 brand new. I bought it while on vacation about 950 miles from home. I got it home and right out of the box it would spin the motor nicely, but the train barely moved. I took it apart too and found that the shaft from the motor would "slip" where it connected to the worm gear shaft. I simply glued it together so the two shafts would spin turn for turn. No more trouble...it worked great! I wasn't going to try to send back a train that was purchased 950 miles from home...and for only $29. I guess I got lucky. Good luck!

Chad


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## radfan (Mar 7, 2010)

matt said:


> It doesnt move at all on a straight away with just four cars on it. I can see the drive shaft spinning where it meets the worm gear.


You need to take a close look to see if both parts of the coupling are moving and if this is the case then it's a simple fix, but you need to remove the gear tower from the loco to do it well.


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## matt (Jan 24, 2010)

radfan said:


> you need to take a close look to see if both parts of the coupling are moving and if this is the case then it's a simple fix, but you need to remove the gear tower from the loco to do it well.


there is a collar that the dogbone goes into on one side. The shaft of the worm gear slides into the other side off the collar. Both of the collars have a crack that run through them. I forgot to describe these collars...they are cylindrical with a hole through the middle.


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## mr_x_ite_ment (Jun 22, 2009)

I wonder if it could have cracked while trying to make the first tight turn? In any case, it sounds like it might need to go back...maybe you could exchange it for a shorter loco. Good luck!

Chad


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## radfan (Mar 7, 2010)

matt said:


> there is a collar that the dogbone goes into on one side. The shaft of the worm gear slides into the other side off the collar. Both of the collars have a crack that run through them. I forgot to describe these collars...they are cylindrical with a hole through the middle.


Ok that makes sence to me, The crack is the reason your gears are slipping so if you want to get warrenty work you need to send it back or drop them a line explaining what the issue is, however if your going to just forget about all that and make a fix yourself then strip down the towers from both ends so you can slip the collars off and use some CA to hold them back in place,You need to close the gap where the crack is before you replace them back on the shaft and use a small drop on the end of the shaft to bond the collar to it, you also need to hold the shaft faceing downwards to make sure you dont get glue into the bearing and end up with the whole thing locked up.


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## tankist (Jun 11, 2009)

spinning unequal slipping. so what is slipping exactly? why is it not slipping when on streights? what happens if you hold the cars engine coupled to (on streight.)

as you probably realize, gluing the wrong part of the shaft and the joint will just get you yet another problem on top of your original one. so i wouldn't be an a hurry over that one

appears that the discussion of same topic is spread across threads....


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## mr_x_ite_ment (Jun 22, 2009)

Even if the loco were working perfectly, I am betting it is too long for a 22" radius. I have heard that maybe the trucks turn more to accomodate this. Even still, it looks like a long train to me.

Just my $.02.

Chad


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## matt (Jan 24, 2010)

just to reiterate...the problem does occur on straights, with only four cars in the consist. With the shell off I can see the collar spinning around the shaft of the worm gear. And I appologize about the two threads being about basicly the same thing


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## tonkaman2022 (29 d ago)

matt said:


> I recently bought a Bachmann Spectrum dd40 and during testing I noticed that it struggled when going into the first curve on my test track. My test track has 22radius by the way. So I took the shell off to look inside. After I took the shell off, I put it back onto the track with four cars behind it and what I saw was the drive shaft spinning where it meets the worm gear. Im hoping someone could shed some light on this or should i just send it back?


 I bought one off eBay. One motor missing. Where can I get a replacement. Thanks for any help


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## prrfan (Dec 19, 2014)

tonkaman2022 said:


> I bought one off eBay. One motor missing. Where can I get a replacement. Thanks for any help


The guy who you are asking hasn’t been on here since 2011. You should probably start a new thread rather than reply to one that’s 12 years old.


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## bbunge1 (10 mo ago)

tonkaman2022 said:


> I bought one off eBay. One motor missing. Where can I get a replacement. Thanks for any help


If your Ebay DD40 is an Athearn, they had one and two motor DD40's. I have a one motor DD40 in EMD Demo that still runs fine after years in storage. It even can negotiate 18 in radius track as can all Athearn Blue Box engines.


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