yes

It will be necessary by all

It will be necessary by all reports.  I have a around 10 Proto 2000 GP30's still new in the box and those that I keep and run, I take it for granted I will need to order the gears and replace all.

What is the current source for gears?  Athearn?  Part #?

#60024

Gears

Back when LL GPs were fairly cheap at swap meets, I bought a pile of them and am slowly adding decoders (TCS LL8) and cleaning out lubrication crud. Engines get new axle gears at the same time, and I use a Sharpie to mark an "A' for axles on the bottom of the fuel tank. If one breaks in an active engine, all four axles get the fix. I'm using the Athearn gears.

Replacement is very easy. Pop the bottom cover off the power truck, lift out the axles and pop the old cracked gears into the can or a marked Ziploc.

Timely

I've got an old P2K E8 unit I'm rebuilding and turning into DCC and the wheels are not in great shape and I haven't even looked at the gears.  Figured I'd replace them all at once given the reports I've heard.  Was going to go with NWSL replacements.

Unfortunately E gears are not the same as the others

They have the same failure source, but are not the same diameter.  Athearn did not make an engine with this size gear.  The source for these is limited.  They all eventually crack, but where you are in the failure cycle is a variable. I use to buy otherwise trashed units for this kind of part.  40-50 percent would be ok.  There is no guarantee how long those will last, but neither is there on a set of new gears.  The crack failure source is cyclic fatigue.  This can be due to load or temperature or both.  Good luck in finding some replacements.

Millage Will Vary

I have more than half a dozen old LL Proto 2000s which have been running for decades and hundreds of hours. I have only replaced less than half of the wheel sets, but many of those replacements have been due to wear and or pitting of the wheels. So blanket statements regarding the reliability of the gears is of little help to the Op. I would suggest that you clean, lube, inspect and run the engines on DC to check how well they run before replacing any wheels. If, down the road, you experience a failure wheel replacement is fairly easy.

True.  You will probably know

True.  You will probably know it if you do have the cracked gears.  There are certain types of LL  Proto 2000 which reportedly have a very high rate of cracked gears.  The GP30 is one of them.  I sold one a couple months ago and the guy, who knew about the problem, reported sure enough, he had to replace the cracked gears.  I have at least 9 others and I won't be surprise if all nine have one or more cracked gears based on all the reports, at least for the model.

Prevent or repair?

Odds are that the gears will fail.  Replacing the gears then becomes a matter of replacing them now, i.e., preventing failure, or replacing them after they fail.  Choice doesn’t matter much, but be sure to get a set of those Athearn replacement gears now.

See my blog for details about replacing axle gears, idler gears, and iron containing bearings in more than 20 locos.

Athearn and NWSL

Athearns are way cheaper but I seem to get about 2 out 10 repeat cracking when replacing.

I've had problems with gear breaks (among other things) in recently purchased Athearn RS3s. Those take a lot of tweaking to get them up to snuff. Athearn has made good on replacements, but I'm slightly embarrassed to ask for replacements each time I put another one in service.

The NWSL fit well and seem to be of higher quality, but you pay more. Great wheel set replacements, but again, you pay more. I've used these to replace wheel sets in my P2000 FA1s.

Hats off to both companies on customer service.

If you have time, clean the lubrication out. Both companies use Skippy Peanut Butter.

Bob

Omaha

Boiled gears

I wonder if boiling the gears would prevent cracking... Years ago when I raced R/C cars we would take all the nylon/plastic parts and boil them prior to assembly. The parts would not crack or break as easily after being boiled.

I always disassemble clean

I always disassemble clean and lube everything before putting them into service. When doing that I inspect the gears and if I have any that are cracked they get replaced. This takes more time than unwrapping a package but I believe it is worth while. From some of the chunks of solidified lubricant I have removed while doing this I suspect that I have saved a few gears by doing this.

I also check the wheel gauge, coupler height, and replace non kadees with kadees  I also look to see if I need extended length couplers so foot boards will not become contact points between units.

Huh?? Boiling... A note on Plastics will tell you NO

@Kregan: 

Among the properties of Nylon (Thermoplastic / not thermoset) is that it is Hydrophyllic... It LIKES WATER, and will absorb it (slowly).  This absorption  degrades the plastic-  it Does NOT help!

(you may have had a different plastic... delrin is similar in appearance and properties to nylon... and may have fooled you.  I don't know if it gains any advantage by boiling.)

Out of curiosity, has anyone

Out of curiosity, has anyone just tried to repair the gears with a drop of CA? I have a fair number of 80s-90s Athearn and old P2K that either have bad gears, or they crack after service and while the athearn parts are cheaper than that NWSL, Even the gears alone are pretty pricey. 

gluing won't work

Simple answer..

It is well known about those gears.. and since you will have the loco apart anyway, why not do all you can while it is opened up.. IMO it is better to do all work while things are opened up, than open up again  later. Hopefully you can take care of all the work once and never have to open it again..hopefully

Replacement Wheelsets

I just received  several packages (3 each) of Walthers geared axle replacement sets for the early P2K E-units. They had been backordered since early summer but are back in stock.

As mentioned previously, the Athearn parts will not work in the Es. Gear mismatch will fry a decoder pretty quickly.

Ream 'em...

Just learned from a friend in the DCC installation/custom/repowering business to ream the replacement gears with a #43 drill before installing. Doing so results in there still being enough friction fit to grip the axle, but less stress on the axle gear.

I just received 4 packs of Athearn gears yesterday, and sat down at the workbench to replace the gears in one of my afflicted P2K GP7's. There was no way the gear would have held up without drilling out the gears to fit the axles better. (The gear essentially would have been a press fit onto the axle. Ridiculously tight.)

SO... I will see how well that helps the gear to keep from splitting.

Andre

Interesting

Reaming is a good idea that has to be done with care.  Executed properly and the static stress will be lowered, which will reduce the part failure rate.  Great idea just be careful.

Cleaning out old lube

I've seen MULTIPLE references to this problem of 'peanut butter consistency gear lube' in Proto engines,...and everyone says clean old lube out and replace it. But no one suggest what to use to clean old lube out,....safe fluid for plastics??

Is mineral spirits safe for plastics?

I think rubbing alcohol is safe.

I've used it to clean gears and plastic wheels before I was able to replace plastic wheel sets with metal.  In fact I have a few cabooses that still have plastic wheel sets.  Mineral spirits is good for cleaning track, but you don't want to use it excessively.  The electrical problems connected with using rubbing alcohol to clean track does not apply to gear sets.  I either blow dry the gears with compressed air after cleaning, or just set them aside for long enough for the alcohol to evaporates off of the gears before I put the trucks back together and lube them.

I use Super Clean in an

I use Super Clean in an ultrasonic cleaning tank.