Several months ago, I bought 2 custom-painted and detailed Life-Like GP-'s. Both seemed to run fine during my test run but just the other day, one of them started having problems. It jerks along and “whines” a little bit. I noticed that the jerking isn’t just on curves but on straightaways also. It sounds like something is “binding” inside. The wheels are clean and so is the track, so that’s not the problem.
I took the engine apart to look for flash on the gears but found none. I greased the gears and also checked to be sure the electrical pick-up wires that are soldered to the clips above the trucks are okay. I checked to be sure the worm gear doesn’t have too much play because if there is, then you need to add a washer to reduce the play.
I literally checked everything that is suggested in the “Athearn Locomotive Tuning and Upgrade” book because these Life-Like engines are obviously a copy of the Athearn drives and experience the same problems.
I also noticed the typical “thumping” you get when one of the axle gears is cracked on these units so I replaced the cracked gears. Life-Like had sent me a whole bunch of the axle/gear assemblies some time ago when I had other engines with cracked gears.
I was having issues with one of my Athearn SW7s a little while ago. It was stalling at random points with no visible explanation for the stalls. I eventually tracked it down to one of the trucks that would hesitate every couple of revolutions. After disassembly and a close inspection of the gears I found no flash in the cogs and no visible cracks. I asked my LHS owner about the problem and he suggested using a fine toothpaste to artificially wear the gears down a bit. Instead I decided to use a small file and sand all of the gears a bit and that fixed the problem for me.
Had same problem with same engine. What I discovered was the worm gear on top of the truck was slipping. (it was solid to the motor but didn’t mesh completly with the gear in the truck) In my case I think it happened because of a speed mismatch in MU operation. Anyway it sounded just like the cracked gear problem. I ended up putting a spare truck in and everything worked great.
I’m sorry to relay this answer to you, but when you siad that the locomotive is thumping and jumping, it’s not slipping gears or lack of oil. Instead it’s a bigger problem. One of the gears in the trucks of your locomotives is broken. In other words, it has a crack in it. Open it up and look at each of the gears. You will notice in one of if not more a hair line crack that runs down the gear. I had this problem once and opened my GP18 up and looked at the gears. 2 of the three gears h
Those locos are famous for cracked axle gears. Replacements available from Walthers or you can use Athearn’s, since the Proto drive is a copy of Athearn’s. The wheels just pull off the gear.
As other have noted in this thread, you’ve probably addressed the thumping by replacing the cracked gears.
However, the jerking and whining are probably the worm shaft bushings in the gear tower. If they’re not damaged too badly, a good lube job may do the trick. Note that you have to disassemble the gear tower to lube it properly. Unfortunately, all that weight that makes them decent pullers prevents one from getting in there to do a proper lube job.
If that baby is like the GP30, I hope you have a couple of hours to rub together for disassembly, cleaning, relubing and reassembly. They put some of the screws on the GP30 in some interesting places.