Trains.com

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Broken drive shaft Bachmann HO?

8304 views
23 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    December 2009
  • 114 posts
Posted by Penn Central on Thursday, January 2, 2020 8:22 PM

Thanks for all of the insight and options. I think I will opt for the CA glue option first and see what happens.

FWIW I purchased this used on Ebay. I contacted the seller and he was kind enough to send me a replacement shaft. Only problem it was the wrong size.

Anyway will try the glue. Thanks again!

  • Member since
    September 2014
  • From: 10,430’ (3,179 m)
  • 2,311 posts
Posted by jjdamnit on Wednesday, January 1, 2020 12:36 PM

Hello All,

mbinsewi
The link to the Bachmann part doesn't give a good view, to see if the drive shaft coupling is there or not.

Yes, the drive shaft coupling is there. That's the point of getting the entire truck Gearbox.

RR_Mel
I’d buy at least one spare, might not be available later on. I ordered a driver set for a Bachmann GS4 and three weeks later I decided to order a send set and they were no longer available.

That's exactly what I did. I am now repairing a second unit and am planning on ordering more replacement Truck Gearboxes. This seems to be a common failure.

To the OP, you can try the adhesive approach but from my experience it just won't work.

I tried CA, two-part epoxy, styrene cement, I even made a sleeve out of brass tubing and press-fitted it over the cracked coupling...all failed.

Each failed attempt meant I had to go back into the guts of the gearbox and attempt another solution.

It was like fitting wheels to a tomato, absolutely useless and an utter waste of time.

I even contacted Bachmann and spoke to a technician in their repair department and asked if the coupling, shaft and worm gear were available as a separate part from the entire Truck Gearbox. 

He told me no. The reasoning was that if the coupling had failed due to age the other plastic parts in the Truck Gearbox were likely brittle and prone to failure too.

I completely agree the Northwest Short Line option is just as viable for a long-lasting repair. 

Good luck and...

I hope this helps.

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

  • Member since
    September 2003
  • 21,669 posts
Posted by Overmod on Wednesday, January 1, 2020 11:23 AM

I'd also attempt the adhesive fix, but with one potential difference.

Straight CA can be brittle, and if there is a cracked part it can cause the bond to fail in shear.  Some versions of CA contain a fine elastomer powder, to give a nominally more flexible bond.  This used to be readily available in LHS-type stores, and I suspect it may still be found online.

The next-best 'alternative' would be gap-filling CA, which may be marketed as 'gel'.

Be very certain that both the shaft and the inside of the coupling are completely degreased and dry before making the joint; I'd suggest seeing if you can make a thin 'collar' of grease or vaseline on the region where the shaft just enters the plastic tower, to keep any CA from wicking in or adhering in there -- using the thicker CA will help prevent this capillary action from occurring in the first place, but it helps to be sure sometimes.

If you can, degrease the part of the universal that goes on the shaft completely, and relubricate and reassemble the shaft after the glue has completely cured.  Remember that it is moisture that causes cyanoacrylate to harden, so in a tight joint it may take some time for the action to complete; don't trust the 1-minute hardening claims to get a suitable bond.  Any bond that is disturbed or weakened before full cure will NOT spontaneously adhere again, unlike contact cement.

If the part is indeed cracked, and if the crack surfaces are clean and degreased, one effect of bonding may be to seal the crack with good integrity and high strength.  It will be at a slightly larger effective diameter than nominal, but will resist opening to more than that diameter when loaded or stressed...

  • Member since
    May 2010
  • From: SE. WI.
  • 8,253 posts
Posted by mbinsewi on Wednesday, January 1, 2020 10:27 AM

The link to the Bachmann part doesn't give a good view, to see if the drive shaft coupling is there or not.

I'd look for any tiny cracks in the drive shaft coupling, and do the CA fix.  Make sure both surfaces are clean.

Ed's link also looks like a fix, if the part is cracked.

Mike.

  • Member since
    November 2006
  • From: NW Pa Snow-belt.
  • 2,216 posts
Posted by ricktrains4824 on Wednesday, January 1, 2020 9:54 AM

I would also vote for the drop of CA first, as that is the easiest and quickest method of repair for this issue. (Also cheapest. A tube way bigger than needed from the dollar store gets a pack of up to 4, for $1.)

Then, if that failed, I would advance to more options, such as replacing parts. 

No experience with replacing this part, but does the replacement also not need glued on? We are still talking about a (relatively) smooth plastic piece press fitting over a (relatively) smooth metal piece, so would not the same issue occur if glue was not used?

I'm basing that off of the fact that a replacement flywheel needs to have glue holding it on, and while the universal isn’t quite the exact same thing, they both still press fit over a smooth metal shaft, and both can hit a pretty high RPM.... 

Ricky W.

HO scale Proto-freelancer.

My Railroad rules:

1: It's my railroad, my rules.

2: It's for having fun and enjoyment.

3: Any objections, consult above rules.

  • Member since
    December 2004
  • From: Bedford, MA, USA
  • 21,483 posts
Posted by MisterBeasley on Tuesday, December 31, 2019 5:14 PM

I have a BLI Hudson, a medium sized steamer.  I had a similar problem, only the shaft just slipped inside the coupling.  Really, a drop of CA is all it took.

If the OP wants to fix this and is thinking of a replacement drive train, give a cheap drop of glue a try.  Sure, it might fail, but if you're looking at an expensive replacement, try the glue first.  It may be fine.

It takes an iron man to play with a toy iron horse. 

  • Member since
    December 2001
  • 1,190 posts
Posted by mvlandsw on Monday, December 30, 2019 8:59 PM

I had the same problem with a Bachmann sharknose diesel. I drilled a #77 hole, perpendicular to the crack, through the universal and the shaft and put a piece of wire,  bent over on both ends, through the hole to lock the universal to the shaft.

That method is not practical for the inexperienced though.

There needs to be a better construction design than force fitting plastic pieces on metal shafts. This is a constant problem that affects almost all manufacturers eventually.

Mark Vinski

  • Member since
    January 2009
  • From: Bakersfield, CA 93308
  • 6,526 posts
Posted by RR_Mel on Monday, December 30, 2019 7:51 PM

jjdamnit

Hello All,

If it's a GP then this is the part from Bachmann...

https://estore.bachmanntrains.com/index.php?main_page=product_info&cPath=68_185&products_id=1306

Hope this helps.

 

I’d buy at least one spare, might not be available later on.   I ordered a driver set for a Bachmann GS4 and three weeks later I decided to order a send set and they were no longer available.
 
 
 
Mel
 
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
 
  • Member since
    August 2003
  • From: Collinwood, Ohio, USA
  • 16,367 posts
Posted by gmpullman on Monday, December 30, 2019 6:44 PM

I have repaired many Athearn, Proto 2000 and Bowser locos with this kit:

https://ppw-aline.com/collections/miscellaneous-re-powering-parts/products/12030-universal-joints-coupling-assortment

I only have three Bachmann locos, a pair of EM-1s and an Alco switcher which, so far, have not had any drive-line problems, therefore I can't guarantee these will fit.

Regards, Ed

  • Member since
    September 2014
  • From: 10,430’ (3,179 m)
  • 2,311 posts
Posted by jjdamnit on Monday, December 30, 2019 6:26 PM

Hello All,

If it's a GP then this is the part from Bachmann...

https://estore.bachmanntrains.com/index.php?main_page=product_info&cPath=68_185&products_id=1306

Hope this helps.

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

  • Member since
    January 2009
  • From: Bakersfield, CA 93308
  • 6,526 posts
Posted by RR_Mel on Monday, December 30, 2019 6:20 PM

jjdamnit

Hello All,

Sorry to be the bearer of bad news but glues won't fix this problem.

I have had several failures like this on Bachmann GPs.

The only real solution is to replace the cracked linkage.

Unfortunately, Bachmann does not sell the individual female part of the linkage. You will need to replace the entire truck gearbox.

 

The cost was $45.00, including return shipping.

The entire process took about 2-weeks from when Bachmann received the unit to when it arrived at my door.

Hope this helps.

 

What size shaft and ball is the Bachmann?  I have a bunch of Athearn 2mm shaft .156” ball universals I could send him for free!  The NWSL balls I stock are 2mm shaft with ⅛” ball.
 
EDIT:
 
Another Backmann AngryThumbs Down
 
 
Mel
 
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
 
  • Member since
    September 2014
  • From: 10,430’ (3,179 m)
  • 2,311 posts
Posted by jjdamnit on Monday, December 30, 2019 6:14 PM

Hello All,

RR_Mel
Before I would pay Bachmann $45 I would replace the entire drive line with a $5 NWSL Universal Kit. Most likely a much better repair too.

The caveat would be if you don't have the tools or experience to perform the "surgery".

If the OP doesn't want to invest in tools and time, $45.00 might not be that much of a hit.

On the other hand, if the OP will be doing future D.I.Y. projects then the initial cost of the tools and the learning curve will be worth the investment.

Just giving the OP some options to his situation.

Hope this helps.

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

  • Member since
    December 2015
  • From: Shenandoah Valley
  • 9,094 posts
Posted by BigDaddy on Monday, December 30, 2019 6:10 PM

[quote user="BigDaddy"https://tinyurl.com/v3y7z8a[/quote]

This opened in a new window that I didn't see.  I don't think it's what you need.  I vote for NWSL

This is the Bachmann part which has way more than you need

https://estore.bachmanntrains.com/index.php?main_page=product_info&cPath=68_185&products_id=7579

Henry

COB Potomac & Northern

Shenandoah Valley

  • Member since
    January 2009
  • From: Bakersfield, CA 93308
  • 6,526 posts
Posted by RR_Mel on Monday, December 30, 2019 6:06 PM

Before I would pay Bachmann $45 I would replace the entire drive line with a $5 NWSL Universal Kit.  Most likely a much better repair too.
 
 
 
Mel
 
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
 
  • Member since
    September 2014
  • From: 10,430’ (3,179 m)
  • 2,311 posts
Posted by jjdamnit on Monday, December 30, 2019 5:50 PM

Hello All,

Sorry to be the bearer of bad news but glues won't fix this problem.

I have had several failures like this on Bachmann GPs.

The only real solution is to replace the cracked linkage.

Unfortunately, Bachmann does not sell the individual female part of the linkage. You will need to replace the entire truck gearbox.

To do this go to the Bachmann website and click on the "Parts, Service and Information" link.

From there you can look at a diagram of your particular unit, under "Product Reference".

Then you can go to the "Order Parts". Choose from the column on the left "HO Parts".

Choose the type of locomotive and order the part(s) in question.

Another option would be to get the linkage part(s) from NortWest Short Line. You will need to measure the diameter of the drive shaft of the motor, then order the correct kit.

The above two options will require you to go deep into the guts of the unit. You will definitely need a set of jewelers screwdrivers and possibly the ability to solder if there are any broken wires.

The third option would be to send the unit to Bachmann for repair. The unit does not have to be under warranty for them to do the work.

On the Bachmann website click on the same "Parts, Service and Information" link, then click on the "Service Dept. Info" link.

This will open a window with a "Repair Request" button. Click on that button, set up an account and fill out the form.

You will need a Return Merchandise Authorization(RMA) number, which will be generated for you.

Follow the instructions, print out the label, pack your loco and ship it off.

The repair department will contact you if the item is out of warranty with an estimate for you to approve.

I recently sent in a 0-6-0 steamer in for out of warranty repair. The cost was $45.00, including return shipping.

The entire process took about 2-weeks from when Bachmann received the unit to when it arrived at my door.

Hope this helps.

"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"

  • Member since
    January 2009
  • From: Bakersfield, CA 93308
  • 6,526 posts
Posted by RR_Mel on Monday, December 30, 2019 5:37 PM

CA is Super Glue.  The universal is a universal joint, the black piece hanging down off the shaft.  It has to swivel freely on the opposit end that goes on to the shaft, don’t let any excess glue to get into the ball joint.
 
Keep the glue away from where the shaft goes into the gear housing so that it doesn’t glue the shaft so it can’t turn.
 
 
 
Mel
 
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
 
  • Member since
    December 2015
  • From: Shenandoah Valley
  • 9,094 posts
Posted by BigDaddy on Monday, December 30, 2019 5:34 PM

this might be the part you need, but I can't get the larger image to work.  Therefore if you have a crack or the glue doesn't work, ask on the forum

https://tinyurl.com/v3y7z8a

 

Henry

COB Potomac & Northern

Shenandoah Valley

  • Member since
    December 2009
  • 114 posts
Posted by Penn Central on Monday, December 30, 2019 5:24 PM

BigDaddy

It's hard to see a tiny crack in a black piece of plastic.  I've not seen complaints of that part cracking, but Bachmann is known for gears cracking. 

I've read good things about the Bachmann forum and the they have online parts and parts dagrams.

 

Thanks Henry. Do you mean a user forum on the main bachman site?

  • Member since
    December 2009
  • 114 posts
Posted by Penn Central on Monday, December 30, 2019 5:23 PM

Wolf359

Can you see if it has any cracks in it? If not, my suggestion would be to clean the ends of the parts in question, put a very small dab of supper glue on the metal worm shaft you have circled and push the universal joint back on to it. If that doesn't work, then you probably need a new part.

 

I dont see any cracks but will check. So like Mel you're saying glue this universal part directly in place?

  • Member since
    December 2009
  • 114 posts
Posted by Penn Central on Monday, December 30, 2019 5:22 PM

RR_Mel

It’s the universal slipping off the worm gear.  I small dab of CA should take car of the problem.  Be careful to not get any in the ball joint or glue the shaft to the gear housing.  Make sure the shaft and universal are free of lube before using the CA.
 
 
 
 
Mel
 
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
 

Thanks Mel. I have to ask (sheepishly) what is CA and universal? And are you saying i can also glue the shaft to the gear housing?

Sorry no experience with these types of motors. 

 

  • Member since
    December 2015
  • From: Shenandoah Valley
  • 9,094 posts
Posted by BigDaddy on Monday, December 30, 2019 5:02 PM

It's hard to see a tiny crack in a black piece of plastic.  I've not seen complaints of that part cracking, but Bachmann is known for gears cracking. 

I've read good things about the Bachmann forum and the they have online parts and parts diagrams.

Henry

COB Potomac & Northern

Shenandoah Valley

  • Member since
    December 2014
  • 443 posts
Posted by Wolf359 on Monday, December 30, 2019 4:40 PM

Can you see if it has any cracks in it? If not, my suggestion would be to clean the ends of the parts in question, put a very small dab of supper glue on the metal worm shaft you have circled and push the universal joint back on to it. If that doesn't work, then you probably need a new part.

  • Member since
    January 2009
  • From: Bakersfield, CA 93308
  • 6,526 posts
Posted by RR_Mel on Monday, December 30, 2019 4:36 PM

It’s the universal slipping off the worm gear.  I small dab of CA should take car of the problem.  Be careful to not get any in the ball joint or glue the shaft to the gear housing.  Make sure the shaft and universal are free of lube before using the CA.
 
 
 
 
Mel
 
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
  • Member since
    December 2009
  • 114 posts
Broken drive shaft Bachmann HO?
Posted by Penn Central on Monday, December 30, 2019 4:26 PM

Hi all I have a used Bachmann GP40 with a drive shafts that keeps slipping off the gear.  Not even sure if I'm using the correct terms here. Anyway previously it happened occasionally that I just popped the shell off and slid the shaft back in place with a small screwdriver.

Now it happens constantly. Is this just a replacement part needed?

Heres some pics.

First one to give you an idea of what I'm working with.

Second one is a close up of it slipper off.

Third one is after I slid it back in. 

 

 

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Users Online

There are no community member online

Search the Community

ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
Model Railroader Newsletter See all
Sign up for our FREE e-newsletter and get model railroad news in your inbox!