I cannot for the life of me get the screws off that hold the couplers in place. I have never re-moved them, and the engine was brand new when i got it, i applied all the details and everything a while back, now i wanted to try and replace the couplers and open up the shell, and i cannot loosen the screws that mount the couplers in place. They are so dang tight from the factory, they just wont budge. I even tried to put the screw driver in my power drill and it just wont come loose, its just stripping.... Its almost like there welded in place or something, and its really frustrating!

What should i do? Should i contact KATO? Can anyone suggest something to do? The screw on the front of the loco is kinda stripped now, and the rear one is also a little stripped

Righty - Tighty

Lefty - Loosey



They may have used a thread-lock, but what you describe is extreme...

The only thing that I can think of is touching a hot soldering iron to the head of the screw for a few seconds.

It may help to burn off the thread lock...

The other thing may be to use a dab of penetrating oil like WD40 to soak into the threads.

Lastly, if all else fails...

Drill out the screws and then re-tap the holes for slightly larger replacement screws when you re-assemble it.

Hi Josh,

Have you some side cutters you could grip the underside of the head of the screw while you try and undo it ........ support the loco while you try it in a box of polystrene chips .... the soldering iron may loosen the thread lock but no idea why it is so tight try a mail to Kato U.S.A. for advice.

Thanks guys for the tips, ill try that soldering iron thing, if that doesnt work, ill try and manually loosen it with some pliers if i can get a grip on it lol

Hopefully one of these works, if not, i guess ill be calling KATO to see what they say lol

Trucklover Wrote:Thanks guys for the tips, ill try that soldering iron thing, if that doesnt work, ill try and manually loosen it with some pliers if i can get a grip on it lol

Hopefully one of these works, if not, i guess ill be calling KATO to see what they say lol

Hi Josh,

I would use these cheap sidecutters i bought from radio shack



Grip the screwhead and hopefully there is a bit of give in the screw the angled edges will grip and as you squeeze the cutters together while undoing the screw hopefully the cutters will close together the angled edges pulling up the screw and it will come out.

Hi Josh,

I googled Kato and found the Parts List for the HO SD90/43MAC

The screws look like they have a thick shank and a thinner set of threads that are possibly self tapping.

[attachment=1422]

They may be locked with metal chips from the tapping process so try the WD40.

Here are the replacement parts:

900100 Screw For Frame Mount Couplers, 6 ea $1.25

953030 Coupler Set: X2F w/ Screw, 1 pr $2.00

953050 Coupler Set: Type E Magnetic Knuckle Coupler, 2 ea $2.00

I would not try the soldering iron trick. Leaving the iron on for slightly too long could damage the plastic. I think I would write to Kato, USA and see what response they give you first. They may want you to send the model back to them for repair. If you break it trying to remove the screws, they may not want to replace it because of abuse. Put it away and give them a few weeks to respond to your inquiry.

Russ Bellinis Wrote:I would not try the soldering iron trick. Leaving the iron on for slightly too long could damage the plastic. I think I would write to Kato, USA and see what response they give you first. They may want you to send the model back to them for repair. If you break it trying to remove the screws, they may not want to replace it because of abuse. Put it away and give them a few weeks to respond to your inquiry.

Thanks Guys for the help and replies

Russ, this is a good idea and exactly what i am going to do If i damage that loco, and they say they wont tough it because of the abuse, then i certainly will not be a happy camper lol