Regearing Kits

Has anyone used the ERNST kits for Athearn locos ? What were your results and do you have any tips ?

I have installed a number of the ernst kits , mostly in the old metal sideframe trucks. The only inside bearing trucks I did were a couple of SD40-2s.
If gear noise bothers you Find another alternitive such as a replacement motor with a lower RPM.
If your ok with a little gear noise, follow the instructions included, they are pretty straight forward and easy to follow. The only thing I do extra on the outside bearing trucks is to add shims to reduce the endplay of the wheelsets.
I realy liked the difference as far as slow speed running capability and less current draw .
If you add a little extra weight to the loco there won’t be much that will compare in pulling power.

They are loud.

Make sure that you follow the instructions EXACTLY, the gears have to be put in correctly, or you will not change the gear ratio…

Make sure the gears and the truck parts are complete free of burrs and flash.

If the noise is an issue, and you are on a limited budget, the Mabuchi motor used by Mantua in thier last 8 wheel drive GP20 and F7 units, will drop the speed of an Athearn locomotive by ~30%, with a cooresponding improvement in low speed performance.

I have used the kits in two Athearn SW7s. It did make them noisier, but I like the reduced speed and increased pulling power. Since then I have repowered both locos with ALine kits. The noise is still their, but really only noticable if I have it full throttle. It’s fairly quiet at lower (switcher speeds). Really the only problem I have now with it is weight. It can pull much more than the traction it can make…and their just isn’t too much open space to put weight in those.

I used their kits to regear and remotor Athearn SW7 Cow and Calf units, but could not tell any significant difference in running qualities other than the fact that the Athearn growl quietened down a little.

I strongly suspect that you got one of the gears in backwards, resulting in no change of ratio. The difference between the 12:1 stock ratio and 32:1 Ernst is significant.

I’ve repowered about 10 Athearn loco’s with Ernst gears and I’m very pleased. [:D][:D] The only odd thing besides the noise is that no two engines turn out the same. Some can crawl super slow and others don’t take to well to the gears despite repeated reworks. That may be due to Athearn’s low quality engines. [:(] Over all, it’s worth it or I wouldn’t have reworked 75% of my Athearn fleet.

Has anybody seen the gear I dropped? [sigh]

DR;

Have you done the Pearl Drops thing?

Never heard of the Pearl Drops thing. Fill me in? [?]

I used an Ernst gear set in my S12. I too used the Pearl Drops method to break in the gear train - I was obsessive with it, to the point that the truck with the worm off will ROLL on a piece of track as you tilt it back and forth, no sliding. With the stock Athearn motor still in place, it runs GREAT! Nice and slow as a switcher should. I replaced the wheels with NWSL ones, which gave me far better electrical pickup, but cut back traction a bit, so I stuffed every available place with weight. Still stalled on the old club layout where I was a member - on a 2.5% grade with 50 cars! I stacked extra weight on top just to see what would happen, NEVER got it to stall, it would always spin, but I WAS able to get it to haul those 50 cars up the grade - albeit with an extra ‘load’ of weights draped over the hood. This loco is capable of continuous slow speed running that is even better than my P2K locos, and the only noise is from the stock Athearn motor. The trick there is to use an eraser and poli***he commutator segments - GREATLY quiets the motor down.

–Randy

Thanks guys. Now I know why my first adventure with an Ernst kit didn’t work out very well. That switcher needs some polishing!

Jim

I am into steam only, but a friend had all the problems I read about here. The Pearl Drops treatment really did work on the Ernst gears. My friend disassembled his unit one final time, cleaned the gear lubricant from the gearbox, gears and bearings. He then applied powdered graphite as a lubricant. Talk about smooth running, and dead quiet as well. I am impressed, but not enough to change my layout to a later time period so I can run diesels. All locomotives seem to benefit from an upgrade to better quality motors.

Tom

Ink eraser or just a regular rubber pencil eraser?

Nfmissio, Guys

One thing though. I will be using the Pearl Drops method for all of my Athearns.

However, is it possible to quiet an Athearn even more without reducing the gear ratios? I still want my FP45s to be able to hit 80 scale m.p.h (some of the prototypes did 90!).

From what I understand, these regearing kits provide quieter running, but the top speed is reduced considerably. Great for switchers and even some Geeps, but not for the “Hot Shots”.

I appreciate your feedback, Thanks![:D]

I have one of the Ernst kits in an Athearn SW1500 and I’ve had mixed results. At first the gears were very stiff and noisy. I then used the Pearl Drops method and gave it several hours of break in, which improved it considerably. There was also a molded ridge inside the gearbox that was acting as a brake against the large gear that meshes with the worm. I trimmed that down and it moved much more freely.

I cleaned the gears and reassembled them with graphite lubricant, and they rolled well but were still somewhat noisy. I then cleaned out the graphite and used some Labelle 106 grease and that quieted them down more.

The switcher runs better than it did for sure, and the overall noise level is now pretty low. However, it still has a bit of jerkiness that’s especially noticeable at crawling speeds. It seems to speed up and slow down in very tiny increments. I had previously installed a PPW repowering kit in this locomotive so I don’t think the motor is a problem. Maybe it just needs a bit more tinkering.

With regard to Athearn noise in general, I’ve noticed that aside from the gears, noise also comes from the universals. I’ve found that using a spline shaft that is long enough to completely fill both cups and eliminate all or most play helps. The cups tend to wobble and this makes noise, especially at high speeds. If the spline shaft is long enough it will help to keep them from doing that. At moderate speeds most of mine now run pretty quiet, though at full throttle they still growl. A little grease inside the cups also helps a little.

Someone else made a regearing kit(don’t remember the name) that would fit between the motor and the truck gear train. I put both it and the Ernst into an Athearn GP9 and I think the gear ration was something like 120:1! Noisy, but oh so slow.

Bob Hayes

If noise is an issue, besides addressing the gears, you can replace the ‘U’ joints and poli***he armatures on Athearn units with very good results usually.

Where is a good place to purchase Ernst Gear sets?