Here's my 2 shillings worth. Buy the Athearn gears and replace all of the original gears..
Larry
Conductor.
Summerset Ry.
"Stay Alert, Don't get hurt Safety First!"
You know the routine - buy some from Athearn and problem solved. If you use gears out of a P2K GP20, you may end up having to replace those too so might as well do it right and get them replaced properly once and for all. BTW, I have 10 P2K GP30's I'm going to need to do the same thing also.
Rio Grande. The Action Road - Focus 1977-1983
You should be able to see the crack once gear lube is removed...If You can't..it will be the one that You can turn the wheels/axle's freely in the gear. All the engines You mentioned, the gear's should fit. As long as the axle shaft is the same diameter and it is a twelve (12) tooth gear. If You would like to get replacements, (which would be the wisest choice) Athearn #ATH 60024 gear axle's will fit, they come six in a pkg.
http://www.athearn.com/Products/Default.aspx?ProdID=ATH60024
Take Care!
Frank
happy new year to all. I have an older proto 2000 what seems to skip on the track. I think it's a cracked gear and I have a wrecked proto gp 20 and some athearn gp9s some old sd40s can I use their gears? Also can you see the crack in the gear? rambo1..