Adding P&D power kit to GP9 shell

[up148]

Yep, I'm flip flopping around again (setting the FEF aside) and decided to finally (30 years later) power the P&D body kits I bought. I also plan to use the brass chassis I got from Ron at the same time.

I know there is/was a problem, as well as some fixes for the infamous cracking gears, but I don't remember much about it. Since these power kits are original from the 90's I'm sure they're cracked or will crack, so I'd rather do the fix now rather than later.

Any comments or suggestions would be appreciated.

[bob turner]

If they haven't cracked yet you may be in luck. Raoul and CLW aged their axle gear material prior to cutting. I think P & D and Atlas caught on after failures started popping up.

[up148]

I don't remember is it was the tower gears or axle gears that cracked.

[bob turner]

Probably both. After casting, these plastics continue to shrink for about six months to a year. Shrinking around a steel shaft? Only one way to relieve stress, and a cut tooth is a great stress raiser.

Otherwise, Celcon, etc., are great axle gear materials - better than bronze.

[Chris Webster]

I assume this thread is about the Weaver and P&D mechanisms that use a chain on each truck. There is a single gear at the top of the tower and a gear on each of the two wheel axles. P&D used to sell replacements gears and chain, but I don't think they have them anymore (because the store/website is winding down.)

Replacements for the chain and gear at the top of the tower were available from https://sdp-si.com/ the last time I ordered some. Sorry, I don't have the part numbers or direct links handy. SDP-SI also had a larger diameter gear that you could use to raise the gear ratio.

NWSL'S website says they sell replacement axle gears for $12.95 each:
Worm Gear, 48DP, 20 Teeth x 11.5mm OD x 0.170" Face x 1/8" Bore, Delrin Compatible with: Weaver RS3, FA, GP38

It also says they sell replacement wheelsets (with the gears already installed) for $64.95 for a set of four:
Geared Wheelset, O, 40"/172, 1/8" x 1.810" Shouldered Axle, Weaver RS3, FA, GP38 Upgrade Geared Wheelsets (4)

I don't think I've used either NWSL product; I'm pretty sure that the replacement axle gears I have are from P&D.

Assuming the prices on NWSL's website are accurate, you could buy four replacement gears for $51.80, or for just $13.95 more you can get four shiny new wheelsets with the gears already installed on them!

Also, FWIW, Finescale 360 offers an adjustable tower kit for $56.60: Red Caboose GP9 Adjustable Drive I don't have any experience with this product. The modeler who sells it seems to produce it in small batches.

[up148]

Thanks Chris, as usual you are a fountain of information. I've done a lot [will do more] of research since posing my question and found some very interesting threads about many different upgrades. Most are 10-15 years old, but did give me good info. I actually held my hand up for two of the P&D brass truck power kits, but they use the chain drive, so cracked gears is to be expected. I saw the wheelsets at NWSL and might go that way, but it's easy to spend a lot of money upgrading one of these models.

Finescale 360 "had" some great products (gear towers, chassis, motor mounts, electronics shelves, etc.) but they all show to be out of stock and the owner is on vacation until the end of July.......it also looks like he went into HO, so not sure if he'll do another run. Fortunately I bought one of his aluminum chassis some time in the past and have two of the DPH brass frames, so I'm good there.

Thank you for the SPD-SI link. I remember reading articles about using their gears as replacements, but will try to find out which ones. Maybe Sarge will chime in as I'm pretty sure he's done this before.

[Rufus T. Firefly]

Maybe Sarge will chime in as I'm pretty sure he's done this before.

I'd think that he might be your best source of info on this specific.