Tuesday, March 17, 2015

Kato MP36PH mechanical issues

The Kato MP36PH is a good looking locomotive; it is also the first Kato I own with the new drive mechanism, and for the most part it was not a problem. At first…

It started (or I noticed it) when I pushed the locomotive forward over a rerailer. None of my other locomotives rolled! And the sound was unmistakable; there was some slipping going on.

From then it got progressively worse; as I added more cars to the train, going up a grade, or accelerating from a standstill. It would occasionally stop, with what could only be described as a grinding sound from the drive train. Usually turning off the power would correct it, and it would be OK.

And it kept on getting worse, i.e. more frequent.

After digging for reports of problems on line, and finding none, I took the plunge an called Kato in Chicago.

Apparently some of the first models had "too tight of tolerances" in the drive train, and it would slip as I described. I could ship the locomotive back to Kato for a repair, but I preferred to get the parts and do it myself. After what seemed like absolute ages, they finally arrived. But then I managed to misplace them, or leave the train elsewhere when I planned to repair it, or leaving the replacement parts in a box of tools on the other layout.

Yesterday I finally broke down and repaired the locomotive yesterday the task daunted me a bit...

Well, it was not all that hard.

One key bit of advice from Kato: "Keep the new frames separate from the OLD frames. Theu look identical..."

And this is very true!

The doing:

The one-piece truck frame is flexible enough to pry far enough apart to let the gears drop out (after removing the axles), but be careful to keep them separated. The three lower gears appear to be identical, and from there the worm gear and idler are easy enough to tell apart.

Why is this so important? The trick is to put them back in the correct sequence:


From the top of the truck frame, insert the small idler gear that sits beneath the worm gear

Then the worm gear

The lower "middle" gear

The two outer gears that drive the axles

Of course, fitting the truck and the contact strips into the side frames is a special challenge, but with time and care it slips back after a few tries.

I finished this up about 11:30 p.m., so only a short test run to confirm success was made. I will try to get some filming done tomorrow.

I know it is better as you can't push the locomotive and hear the gear slip noise you used to hear. It even sounds a little quieter under power...