Spectrum 4-8-2 LM modifications

[AardvarkMine]

I'm sure these questions have been answered before, so feel free to point me in the right direction...  I have two Spectrum light mountains that run well & I'd like to develop, but I have the following questions.

#1  I've read that shimming the traction tire axle on the LM will improve it's performance.  Are there any step-by-step instructions for this process anywhere?  Or can you tell me what size shim to use & where to put it?

#2  I'd like to put a functional knuckle coupler at the front of my locos... suggestions?

#3  Would like to install a DCC chip w/ sound if possible... again... suggestions?

Thanks - Art

[in_eden]

Buy a heavy mountain. I think it has every feature you're looking for!

[AardvarkMine]

LOL!   I've been told that... just hate to see a loco go to waste.

[James in FL]

I own one of the B'mann Light Mountains.

I have never had a problem with mine pulling eight cars + caboose.
Although I have read internet chatter complaining about lackluster performance concerning this loco I don't see it "right out of the box" as some others have stated.

That being said;
Some report that simply rotating the bearing blocks 90°cures all.
I have not measured the bearing blocks to see if they are square or rectangular.

Some have reported good (better pulling power) by placing a sliver of shim between the frame and the bearing block of the traction tired driver and the frame.
Reports have been all over the board on how much shim is required to achieve desired results.

Scotch®Magic transparent tape and/or 3M® #5413 Polymide Film (Kapton) tape ~ .002in.
Computer printer paper ~.004in
Masking tape ~ .007in.

I cannot recommend a fix as to shim thickness, as stated previously, I have not had a problem with mine and have no need to shim the bearing block.

As far as step by step procedure...turn the loco upside down and secure in a foam cradle, be careful of the boiler shell detail.
Remove the two Phillips screws that secure the driver cover plate to the frame.
Remove the cover plate.
Slightly raise the traction tired driver and slide your shim of choice between the bearing block and the frame.
If you remove the bearing block completely from the frame, be sure to check driver quarter before re-assembly.
Place equal thickness shim under both opposite sides.
Replace the driver cover plate and tighten the two Phillips screws.
The amount of tension you put on the Phillips screws will directly affect the running characteristics of the loco.
Don't torque them, just lightly snug them.

Can't help with #2. I have no need.

Can't help with #3, I run DC and am experimenting with true R/C in n scale, which I feel will make DCC obsolete in short time.

Good Luck.

[AardvarkMine]

Thanks... your advice is greatly appreciated.  I must admit that I too have had good luck with my light mountain.  Pulling 40' cars... my loco pulled 13 plus the caboose up a 2% grade including a 13" rad curve at half speed last night.  That's pretty good in my book... but I'm always willing to work on improving performance.

Your comment about DCC is interesting, what is true R/C and why do you think that DCC will be obsolete soon?