Sell yours and get the new version. Pretty sure the new version comes DCC equipped already. Much betterdrive also.

It all depends on your track work and the engine you are doing it to.
I have several engines that i have removed the weight in the tender or at least cut it in half. They work fine on good track work that is smooth. Most do not have wire betwean  engine and tender or it is very flexible.Try it and if you are not happy put it back in. While you are at it check the wheels on the tender to make sure the roll free
with little resistance.

Remove the tender trucks clean all the contact points for electrical pick-up. Where the springs hit  the brass strips. Where the springs hit the side frame of the truck also. Clean the wheels. Get some electrical contact lube and lube the wheels on the tender. Contact lube is a cleaner with light oil.
Use light oil to lube the engine drivers and the Axel shafts on the pilot truck. Make sure the drawbar between engine and tender is not bent lifting the rear of the engine off the track.  Check the wire between them also. Then make sure the traction tires are tight on the drive wheel and not spinning loose.
Try to loosen all the screws just a 1/4 turn to see if anything is binding ,don't over tighten the screws holding the trucks on the tender because they can prevent the tender from rocking side to side.
When you get done you should have a good running engine in fwd and rev.
I have several of the 4-4-0's and they all run good with some adjustments from time to time.

If you can't find tires for it. I had a Light Mountain that kept loosing one of the tires. Bachmann had none. So i took a very small amount of clear silicon on the tip of a hobby knife and filled the groove. Run the loco upside down and smooth it out. Let dry 24 hours.  Worked like a charm.

I just received a new Light Mountain. One of the traction tires was stretched out and kept falling off. Finally  lost it. Called Bachmann and they had none.
I took some clear silicon on the tip of a hobby knife and filled the groove with it. Running the engine upside down to make sure it had no humps.
Let it dry 24 hrs and it has been working like a charm. Might add a coating of Bullfrog Snot later.

Old traction tires can get hard and brittle with age. This will cause them to slip easy. I have taken Bullfrog Snot and painted it on over them and it grips better. You might also try a thin coat of clear silicone over the traction tire. Both work well and improve grip of the drivers. Make sure you wait for it to dry.

Bob

No need to remove the wheels. If you un-do the rods from the driver you can use 2 toothpicks to stretch the new band around the wheel.
Delicate work but i have also filled the groove in the wheel with clear or black silicon sealer and let dry for 24 hours. Both in N scale and HO .

I have a new HO DCC Northern. Out of the box it works perfect on 22in Radius just fine at all speeds.
What part of yours derails??

Bob

You can use the Bachmann UK web site.
Ehattons in England also ships worldwide. They are like Trainworld in the US.
I have purchased several from Ebay UK. You can use your US ID to sign in, add to your watch list, bid and purchase.

Bob

Try this for more information on the UK models.

http://www.newrailwaymodellers.co.uk/Forums/index.phps forum


Bob

Trainworld still shows some available of the heavy Mountain and 2-6-6-2.
I just purchased the IC Heavy.
Yes they are great engines. I have both the HO and N scale.

Bob

I doubt the clicking sound is coning from lack of oil. Sounds like a linkage rod is loose and only hitting in forward. Tighten all the screws. Also check the plastic sand lines around the wheels to see if they got bent and are rubbing on a wheel. There are also copper wipers used to pick up current that hit the back of the drivers. These also get bent and can hit the spokes of the drivers.
If you remove the bottom cover you can lube the gears just leave all the drive rods on the wheels connected and they will stay in sync. Just lift them up you don't have to remove them all the way.
Run the engine slow and look close and you may see what is clicking.

Bob

The Bachmann model is of the 3781/3784  in the 1940-1950's.
Without research i don't thing it would be hard to do a 3751. How close do you want it to be??

Check the drive shaft coupling where it connects to the truck worn gear. If it is loose it will slip on the shaft. Sometimes they are cracked. Replace it or a small drop of superglue inside the center will hold. Also check the connection to the motor.

Bob

Post your question here in the UK.  You might get an answer since it is Bachmann UK item.
http://www.newrailwaymodellers.co.uk/Forums/index.php