I acquired an Athearn F45 loco today from the LHS used for a great price, with one issue. The front wheels spin freely. I look the top off and the drive shaft is in good condition. Leads me to believe that the problem is with the gears in the truck. I have no experiences opening one of these to check for broken gears. I have looked for a tear down how to and to no avail.

Any ideas or suggestions from the community?

Here is the model

http://www.athearn.com/Products/Default.aspx?ProdID=ATHG67636

Hi,

I had a deal on a pair of Athearn rtr Canadian Pacific gp35. At first I thought that
a good weathering job and a few details here and there was all they
need. But when I started to look for some prototype reference picture
it doesn't take long to realize that those cp model are all wrong.

Fist the Bell and headlight are not at the right place.

Fine, that's an easy job. Let's do it and they will run again in a week.  

Due in Jan, finally delivered today.  Hm,  only 4 months late?

Renumbering decals already in, replacement wheelsets in the same box from the same order.  Kadee #5s on hand - oops, have to order alternative weights....

At least something good.  The replacement wheelsets also cover the ones needed for my caboose superdetailing.

I will say the detail looks good though.

Have to wait on the weights to start construction though, argghhh

I'm starting to think about my future D&W locomotive fleet.  There will be at least 7, possibly 8 available for regular service, not counting whatever Southern locomotives I build for the purpose.  Of those, 5 shared two tender designs, and at least one tender was swapped between two of them in late '39 or early '40.  I do not know if any other tenders were ever swapped, or why the one was.  Depending on the exact date I want to model, I might need either one or both tenders for that one locomotive.