LGB OBB 2095 - seized motor or gears

P

penguin

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Hi all,

I took my LGB OBB 2095 (part number 22962) out to run recently, but one of the motors / drive trains appears to need a bit of repair, as it appears to have seized (sometimes it runs, when going in one direction, but not the other) when I try to run it (the other motor / bogie runs fine).

I took the bottom bogie casing off in case there is anything obviously wrong, which there doesn't appear to be, other than a lot of grease:
Underside of LGB 2095 (22962)

Underside of LGB 2095 (22962)

  • Media owner penguin
  • Date added
Something wrong with this motor / gearing, but currently not quite sure..

I also wonder if the axles (with a crank between them) are slightly out of alignment, given how they currently sit:
LGB OBB 2095 bogie

LGB OBB 2095 bogie

  • Media owner penguin
  • Date added
Same bogie of LGB OBB 2095 (22962) - have the axles potentially become misaligned?

I presume the next step is to take the bogie off and inspect the motor and gearing further, but I'm not entirely sure how to go about this. Do I need to take the main body off in order to remove the bogie? I found the exploded parts diagram on Trainli but it's not clear if I actually need to remove the body to take the bogie off.

Also, once I get to the bogie do I need to take the cranks off in order to get to the motor and gears (per page 6 of the exploded diagram). How do I then best ensure the two axles are correctly aligned when reassembling? Is it just a case of doing it by eye?

Thanks in advance for any help given!
 
A 2095 is quite simple to strip down. Yes, you'll have to take the bodyshell off, but this is only held by four screws (unlike a lot of LGB locos which have many more, including some hidden ones!) - you may find you have to swing each bogie to one side in order to easily reach the screws. Once all four are out (and the brake hoses are unclipped from each end of the loco) then the body should lift off quite easily. Lay the body next to the chassis, taking care not to pull too hard on any lighting cables going to the bodyshell.

Each bogie is held on by one single screw with a large plastic washer - you may find you need to unscrew and remove one or both of the metal ballast weights first in order to access the bogie mounting screws.
Once each bogie is removed (label them carefully as to which end of the loco they come from before you remove them completely), you will be able to unscrew the top plate of each gearbox and lift it off, exposing the motor which will then simply lift out.

It does look from a couple of your pics that the axles, and thus the side cranks, are "out of quarter" - you need to realign them by eye, using the vertical line on each crank as a guide. You'll probably find they are only out by one tooth on the gear wheel, but it can be enough to cause poor running as well as strain on the side rods.

It certainly looks like there is some excess grease in the gearbox, I'd remove most of it with a cocktail stick or cotton bud. Test each bogie unit off the loco, after you've re-aligned the quartering - that MAY be all it needs, or you may indeed need a new motor if you're unlucky. If you do need a motor change, then I'd actually do them both at the same time if funds permit, and keep the "good" old one as a spare for future use.

Jon.
 
penguin said:
Hi all,

I took my LGB OBB 2095 (part number 22962) out to run recently, but one of the motors / drive trains appears to need a bit of repair, as it appears to have seized (sometimes it runs, when going in one direction, but not the other) when I try to run it (the other motor / bogie runs fine).

I took the bottom bogie casing off in case there is anything obviously wrong, which there doesn't appear to be, other than a lot of grease:
Underside of LGB 2095 (22962)

Underside of LGB 2095 (22962)

  • Media owner penguin
  • Date added
Something wrong with this motor / gearing, but currently not quite sure..

I also wonder if the axles (with a crank between them) are slightly out of alignment, given how they currently sit:
LGB OBB 2095 bogie

LGB OBB 2095 bogie

  • Media owner penguin
  • Date added
Same bogie of LGB OBB 2095 (22962) - have the axles potentially become misaligned?

I presume the next step is to take the bogie off and inspect the motor and gearing further, but I'm not entirely sure how to go about this. Do I need to take the main body off in order to remove the bogie? I found the exploded parts diagram on Trainli but it's not clear if I actually need to remove the body to take the bogie off.

Also, once I get to the bogie do I need to take the cranks off in order to get to the motor and gears (per page 6 of the exploded diagram). How do I then best ensure the two axles are correctly aligned when reassembling? Is it just a case of doing it by eye?

Thanks in advance for any help given!
Click to expand...


I can almost guarantee the problem is the motor. As soon as I saw it was a shiny Buhler, its fate was sealed. There was a period of time when those shiny motors were shipped (I'll let you guess where they were made, and it wasn't Germany!) and I've had about four go bad very early in their life. It's possible that the large amount of grease played a role--gets into the motor and they fail prematurely. Once you've got the motor block off you can pull the motor from the top...put in a new one from Champex-Linden and away you go!
If you feel the side-rods, do they feel "tight" or do they have a little "free play" the way it's sitting right now? It should have a little play (both sides) and if it's tight, it's likely out a tooth as mentioned previously.

Keith
 
In the first picture you can see:

1. split gear, the "collar" of the gear casting has a split.
2. way too much of the knurling on the axle is exposed
3. and to reinforce that, the axle is no longer centered in the frame.

In the second picture the drivers are clearly out of quarter.

Add those up, and you have a gear that has both slipped on the axle, put the drivers out of quarter, and is misaligned side to side.

So, it should run like crap, usually run better in one direction, but not great in either and probably has no pulling power.

Greg
 
Hi everyone,

Thanks for your helpful input!

I checked the crank and it has a lot less play than the other (functioning) bogie, so looks like (among other things) it needs to be re-quartered. When I re-quarter them, do I do this by removing the motor (thus allowing the axles free movement), then drop the motor back in and make sure they are still aligned?

To check if the [shiny!] motor is dead and needs replacing, can I just connect it directly to my [analogue] track supply and check how it runs? Presumably I am just looking to see if it runs smoothly or not.

With the cracked "collar" of the gear on the axle, presumably I would need to replace the entire axle (or leave it for now if re-quartering does the trick)?

Thanks again!
 
penguin said:
Hi everyone,

Thanks for your helpful input!

I checked the crank and it has a lot less play than the other (functioning) bogie, so looks like (among other things) it needs to be re-quartered. When I re-quarter them, do I do this by removing the motor (thus allowing the axles free movement), then drop the motor back in and make sure they are still aligned?
Click to expand...

Pretty much, yes. if it still looks to be fractionally out, just lift the motor at one end (a mm or two is enough to disengage the worm from the axle gear) and turn that axle just one gear-tooth in the required direction, then seat the motor down again. Note that the motor will have a little round lug at one end that sits into a notch in the gearbox casing, to ensure that you can't reinstall the motor "upside down" by accident.

You can test run the motor out of the gearbox and see how it runs, putting power directly to the motor terminals with a pair of croc clip test leads. If you want to test the motor IN the gearbox, but with the bogie out of the loco, then remember you will need to bridge the connecting pins, each outer pin to its corresponding inner pin (assuming you've got a 4-pin digital-ready ("D" type) gearbox) - if you're careful you can do this with a pair of croc clips again, just one clip gripping each pair of pins, but be careful not to let the two clips touch! Alternatively if you have some spare push-type connectors that fit the pins, just make up two little jumper leads to bridge the pins. Unless you connect each outer pin to its inner companion, then applying power via the wheels or skates will do nothing - most of us have probably done it at least once, thinking "why the **** isn't it moving?" just before that "D'oh" moment.....

Re the crack in the gear collar, it isn't yet completely split..... I don't know if running a drop of a good superglue down into the crack MIGHT help prevent it from splitting further? I don't know if there is an adhesive that will work on the kind of nylon-like plastic used for the gears, others may know?
Anyway, for the time being I'd most likely just run it, with the thought at the back of your mind that you may have to replace the gear eventually if/when it finally splits.

Jon.
 
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I would move the gear along a bit.. There seems a lot of knurled axle exposed..

Quartering:
You can do this from the bottom, you do not need to get to the motor..
Just take the bottom plate off the 'block. Lift one axle, enough to disengage the gear-teeth, and move it one-tooth (probably all it needs). Pop back down, and check if you have gone the right way.

I sometimes find you get a better result by moving the first axle you try back to where it was, and moving the axle at the other end of the block..

Run the loco dead-slow (in both directions).. You can normally tell if it is binding in one direction or another.

Definitely, remove most (all) the excess grease!
 
PhilP said:
I would move the gear along a bit.. There seems a lot of knurled axle exposed..

Quartering:
You can do this from the bottom, you do not need to get to the motor..
Just take the bottom plate off the 'block. Lift one axle, enough to disengage the gear-teeth, and move it one-tooth (probably all it needs). Pop back down, and check if you have gone the right way.

I sometimes find you get a better result by moving the first axle you try back to where it was, and moving the axle at the other end of the block..

Run the loco dead-slow (in both directions).. You can normally tell if it is binding in one direction or another.

Definitely, remove most (all) the excess grease!
Click to expand...
What Phil said is exactly right the motor on these types DOES NOT NEED TO BE REMOVED TO SORT THE QUARTERING.

After you have done that whilst it is upside down as it were you could put the Bases back on, connect the Skates (on one bogie only) to a couple of Crock Clips if you have them and see how it all runs by connecting to your Power Supply.
 
dunnyrail said:
What Phil said is exactly right the motor on these types DOES NOT NEED TO BE REMOVED TO SORT THE QUARTERING.
.
Click to expand...

Agreed but I'd like to add a small caveat.
It's a very long time since I've worked on one of these but I think the fly cranks pass through dummy outside frames, so the axles won't drop down as easily as on many other locos. I don't recall how the frames are fixed, there'll probably be enough play to rotate the axle idependently of the motor though.
 
Neil Robinson said:
Agreed but I'd like to add a small caveat.
It's a very long time since I've worked on one of these but I think the fly cranks pass through dummy outside frames, so the axles won't drop down as easily as on many other locos. I don't recall how the frames are fixed, there'll probably be enough play to rotate the axle idependently of the motor though.
Click to expand...

That's right, Neil - you MIGHT just about be able to move the axle enough to disengage the gear and do it the way Phil and JonD suggest, but it might be a bit tight as the axles are held in place by the outer frame.
Actually, thinking a bit more about the last time I stripped one of these (which would be when I was building my first "multi-power" loco with onboard batteries and the TVD Dead Rail system), even if you remove both bogie units as I described above, you'll still have to take off the outside frames before you can access the gearbox top plate (motor cover), which will entail unscrewing and removing the cranks from the axle ends.

If you take a look at the first post in this thread:
https://www.gscalecentral.net/threa...-b-b-obb-diesel-to-digital-with-sound.306946/

That will show how the frames are connected to the gearbox unit, though do note that the gearboxes on the old loco in that thread are very early "clamshell" type units that are significantly different from the D type "sandwich" gearboxes that will be on yours - however the frame mouldings and method of attachment is still basically the same.

Jon.
 
On this old engine I would replace both axle gears as when one splits, the other is soon to follow. And there is the other motor block with the same axle gears, and at the low cost of these I would replace all 4.
 
Hi all,

Thanks very much for your helpful comments!

I re-quartered them before taking the bogies off, but that didn't seem to do much - same issue.

Went ahead got the motor out of the gearbox. Running it on its own, I think it's had it - in one direction it doesn't move at all, and in the other it only moves part of a turn before giving up (I think it's a specific set of angles it moves in - if you twist it, it runs a little bit again).

So time to replace the motor(s), and axle gears whilst I'm at it!

Are Champex-Linden worth getting over LGB replacements (looks like I need to order from Germany, and they only re-open in mid Jan!)?
 
penguin said:
Hi all,

Thanks very much for your helpful comments!

I re-quartered them before taking the bogies off, but that didn't seem to do much - same issue.

Went ahead got the motor out of the gearbox. Running it on its own, I think it's had it - in one direction it doesn't move at all, and in the other it only moves part of a turn before giving up (I think it's a specific set of angles it moves in - if you twist it, it runs a little bit again).

So time to replace the motor(s), and axle gears whilst I'm at it!

Are Champex-Linden worth getting over LGB replacements (looks like I need to order from Germany, and they only re-open in mid Jan!)?
Click to expand...

My condolences, unhappily my LGB motor experiences have been similar.
I guess they had a bad batch of commutators at some point in time.
 
penguin said:
Hi all,

Thanks very much for your helpful comments!

I re-quartered them before taking the bogies off, but that didn't seem to do much - same issue.

Went ahead got the motor out of the gearbox. Running it on its own, I think it's had it - in one direction it doesn't move at all, and in the other it only moves part of a turn before giving up (I think it's a specific set of angles it moves in - if you twist it, it runs a little bit again).

So time to replace the motor(s), and axle gears whilst I'm at it!

Are Champex-Linden worth getting over LGB replacements (looks like I need to order from Germany, and they only re-open in mid Jan!)?
Click to expand...


Try our very own Muns (Garden Rail Outlet - there should be an ad on the right of your page) for the motors - he might even have the axles too? Alternatively, Peter at Chalk Garden Rail is the approved LGB spares and repairs agent, but several other dealers should have the relevant bits too (eg: GRS).

Jon.
 
Greg Elmassian said:
Couldn't the motor problem be worn brushes?
Click to expand...

It could, but can't say I have ever had that as a problem..
Normally, it is the commutator that gets contaminated.

I have also had motors which must have been stalled, with current going through them for quite some time?? - Possibly one motor has become jammed, and the loco pushed round the track by the other?
This has caused the windings to heat-up, and swell. Permanently jamming the motor.
 
while i think greg and phil and neil et al have said is correct

let me add, since it can t hurt
1 i have had luck cleaning commutators by spraying the motor and commutator and brushes (if you can access) with contact lube and cleaner, then swabbing or or brushing with soft tooth brush, and then blowing with compressed air, and THEN dipping the motor in meths, remove it and run it-yes i have done this and yes, it can dislodge crud. i do this because while contact lube is initially great, it collects brush carbon and becomes gunk. the motors run better without this stuff, or, only a teeny tiny toothpick end droplet at best.

otoh, the above has proven to be either a long or a short time improvement-and it doesnt always work, but it has a couple of times. if your motor has replaceable brushes, i have found that on some of these motors, the brushes can hang up. if so, work them back and forth and add the teeny tiny droplet to the brush sides for lube.

if the motor, brushes are shot or a winding broken, cleaning wont help, obviously, but it doesnt sound like anything is broken as it runs.
.
ive messed with buehlers and they take time and patience and you cant always see a broken wire, or, if you do, reattach it. AND, be mindful with those tabs, as while sturdy, the will break if repeatedly bent by careless re insertion into the motor block.

and,
2
while i agree about the cracked gear and its slipping, another short time fix would be to completely clean the axles, with detergent, removing every bit of grease, centering the gear, and then, indeed a drop of super glue

i did this over twelve years ago with a NOS 2051S which had a slipping axle gear, i believe it had to have been cracked, but dont recall now. that drop of glue has held and that loco has had a fair amount of running under load. at the time i didnt have a spare, and since ordered the gears, but awaited failure....still waiting.

just suggesting a cheap fix if you have problems getting parts. on the whole things dont seem terribly worn. i think gregs on the money with the cracked gear slipping and being the culprit re quartering. wonky motors are a PITA and the only thing is to replace them. had this on a sound mallet with little run time, earlier this year. yes it was a shiny motor that failed.
no signs of fluid or grease.

finally, check to see that the u shaped hole which crades the axle shaft in the chassis isnt worn, ie elliptical. i had a very old 2076 with new axles and motor and it still slipped out of quarter because the frame had worn and allowed the axles to jump a tooth under almost no load, and did this in only one direction. had to get a new block. im sure some could rig /insert a brass bushing insert , but i cant.

new parts tend to eliminate all the time of tinkering and still not having it right, and the barin damage of disassembly, assembly ad nauseum.

best of luck
 
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I think the fact that LGB sells replacement brushes, and my friend Dan Pierce posted in another place about the different brushes for different motors, it's a common replacement part. When something goes wrong, and you draw a lot more current, the brushes will wear faster, so people that have had few LGB failures won't be as familiar with motors needing brushes.

Greg
 
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