I just purchased 2 of the upgraded rear driveshafts from the Bachmann parts page for 2 of my older Climax locomotives.  What are the instructions on how to remove the old driveshaft and replace with the new?  Do I need to remove these 2 screws?

Yes.  The two screws hold G11BX-00V06 to G118X-00V05.  Once removed the old driveshaft will come out.  Put the new drive shaft in and replace G11BX-00V06 on to G118X-00V05.  There are groves in G118X-00V05 into which the forks of the new driveshaft must be placed; G118X-00V05 will be held onto the center gearbox with a yoke connector so you need to be mindful of that. 

Can you please elaborate on exactly what I need to be mindful of?

Once you have removed the screws that hold the two parts together, G118X-00V05 will dangle from the center gearbox; a plastic yolk connector pressed onto the shaft of the center gearbox holds G118X-00V05 on to the gearbox.  That yolk connector is somewhat fragile so you need to be mindful.  If the yoke connector breaks it's not the end of the world as you can get replacements from Bachmann (https://estore.bachmanntrains.com/index.php?main_page=product_info&cPath=69_641&products_id=10622). 

G118X-00V05 has four "grooves" inside of it; two are for the yoke connector attached to the center gearbox and the opposing two are for the driveshaft.

Ok... I think I got it.  Guess I will find out once I tear into it.

Thanks

I got the 2 small screws out and removed the original driveshaft.  However, I am struggling to get it put back together with the new upgraded driveshaft.

Quote from: Waikiki968 on January 02, 2026, 12:23:23 PMOnce you have removed the screws that hold the two parts together, G118X-00V05 will dangle from the center gearbox; a plastic yolk connector pressed onto the shaft of the center gearbox holds G118X-00V05 on to the gearbox.  That yolk connector is somewhat fragile so you need to be mindful.  If the yolk connector breaks it's not the end of the world as you can get replacements from Bachmann (https://estore.bachmanntrains.com/index.php?main_page=product_info&cPath=69_641&products_id=10622). 

G118X-00V05 has four "grooves" inside of it; two are for the yolk connector attached to the center gearbox and the opposing two are for the driveshaft.

Keith, this appears to be a 2 man job? 

A second pair of hands might help.

Also it can be helpful to remove the rear coupler so that you (and maybe a helper) can stand the locomotive on its back (tender) so that G118X-00V05 is facing up while you are working on it.  If you do this, be sure that someone is holding the loco firmly as it will fall over if it isn't supported!

Here are pictures of how I stabilized G118X-00V05 while putting the new driveshaft in:


OR:  using a pair of Threading Tweezers for a Serger (sewing machine):



(the tweezers themselves: 

And here is a picture of the inside of the (old, broken) assembly with both the yoke and the driveshaft inserted into their respective grooves: 


The key is to stabilize  G118X-00V05  while it is still attached to the center gearbox shaft.  This is tricky and will take time.  Before you stabilize, turn G118X-00V05 so that the screws are easily accessible while you're working.   Don't apply too much pressure with the stabilizing shims as the bolster and the yoke are both old and fragile--only enough pressure to stabilize the bolster while you insert the shaft and then screw the bolster cover back on.  It will take time and patience.