# bachman railtruck slipping?



## square1pa (Apr 11, 2008)

I have a 3 year old bachman rail truck that i converted to battery with a simple on off switch 2 years ago. today I set it on the tracks and the "drive axle" is slipping either from the 
"differential" and or the "transmission" . either way the motor turns the axle spins and the wheels go nowhere and i hear a grinding/slipping noise. Any ideas what this is or how to fix it?
Thanks
ryan

PS there is a 5 and 2 year old anxiously awaiting the repair.


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## Curmudgeon (Jan 11, 2008)

The driveshaft turns with the motor? 
Or only with the rear wheels? 

Did you ever do the "fix" on the final drive under the cab floor? 
If you didn't, it's probably toast.


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## square1pa (Apr 11, 2008)

the fix? the one with the shorter screw yes that i did. the drive shaft turns with the motor the wheels do not.


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## Curmudgeon (Jan 11, 2008)

Okay, the output (differential) is either bad or the u-joint housing is slipping. 
Does it move at all? 
What exactly does the grinding sound like? 
Whirring of slipping bits, or actual gears jumping? 

I had mine all apart once, long ago, before I "loaned" it out.......seems the u-joint housing pushed onto the shaft with the (in) famous "D" shaped hole. 

My only real concern on that is the on/off with batteries, the shock on that driveline could have spun the housing on the diff pinion shaft. 

If the motor turns the driveshaft, pop the driveline out (ball-shaped center, ears just pop off), and see if the pinion flange will just pull off the pinion shaft at the diff. 

Super glue next to a bearing is NOT a good idea, may have to cross-drill and pin it for now, IF that's the issue.


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## square1pa (Apr 11, 2008)

follow up.. i had this apart and the geara ARE slipping in the differential. any suggestions as a fix?


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## TheLordsServant (Jul 7, 2008)

Only suggestion I can come up with is perhaps Bachmann offers the gear(s) as a replacement part that you could buy. Also, I'd probably do something about the On/Off switch, because that probably caused the gear damage in the first place. I'd place some kind of a speed control so that there isn't as much sudden force on the gearbox.


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