Large Scale Central

GP40 pinion gear removal?

Long story short, I bought a Gp40 online that was supposed to have 10 hours run time on it…max(his words). After I got it, that was a lie.

Fast forward to now…

So, i have all the gears replaced, worm gear included, and 4 wheels. Now, I am replacing the motors. I have new motors, but how the heck do you get the pinion gears off the old motor shaft? I really thought there was a set screw holding them on, but there isn’t. I guess they are pressed on?

Yes, They are friction fit. Some use a gear puller specifically designed for this. https://www.amazon.com/Great-Planes-Pinion-Puller-Hi-Strength/dp/B0030GX1V6 However, it can also be done gently with a hammer and a vise.

Dan Gilchrist said:

Yes, They are friction fit. Some use a gear puller specifically designed for this. https://www.amazon.com/Great-Planes-Pinion-Puller-Hi-Strength/dp/B0030GX1V6 However, it can also be done gently with a hammer and a vise.

Thanks Dan! So, how would I go about putting the pinion gear on the new motors?

Matt

The original GP40’s had ill specified motors as I recall. Aristocrat replaced them free of charge. That said the motors are HARD to find with the correct specifications. Are your replacement motors OEM Aristocrat?

Michael

Michael Glavin said:

Matt

The original GP40’s had ill specified motors as I recall. Aristocrat replaced them free of charge. That said the motors are HARD to find with the correct specifications. Are your replacement motors OEM Aristocrat?

Michael

Michael, yes they are oem motors.

Matt Russell said:

Thanks Dan! So, how would I go about putting the pinion gear on the new motors?

Put the motor in the freezer for an hour or two and heat the gear with a torch and it should slide on pretty easily.

For brass gears I always use a mini torch to remove or install the gears. After heating up a gear on a motor shaft, it just slides off by itself.

I also have used a larger torch outside to do the same thing, but in the house at the work bench I prefer the mini for safety reasons.

Matt Russell said:

Michael Glavin said:

Matt

The original GP40’s had ill specified motors as I recall. Aristocrat replaced them free of charge. That said the motors are HARD to find with the correct specifications. Are your replacement motors OEM Aristocrat?

Michael

Michael, yes they are oem motors.

Thanks Matt, I Shoud have inquired about source previously. Please share the vendor for said OEM motors. Michael

Thanks guys! I appreciate it. I will work on them later tonight. Off to run errands now and hopefully get the yard mowed before the storms roll in.

I am sorry, but I can’t reveal where I got them from, because he didn’t advertise that he had them. I just know he got them straight from Navin, and I think I got the last set. It was just pure luck on my part.

Hey Matt,

Was this a yellow box version or is there a way to tell if you have a newer/older style GP40?

i came across a BNIB one that is the yellow box (I think by this time all artisto was yellow box) but they (seller) have no idea if it’s a first gen or second generation one with improved motors/gears.

Looking for advice for the pending delivery and unboxing. Tell tail signs Of broken/old/issues would be appreciated.

Thanks,

Chris

Chris,

I have no idea what version I got. It came with out a box. There is probably a way to tell which version it is, but I have no clue. Greg Elmassian or Ted Doskaris would be able to answer that for sure.

Matt Russell said:

Dan Gilchrist said:

However, it can also be done gently with a hammer and a vise.

Thanks Dan! So, how would I go about putting the pinion gear on the new motors?

Dan forgot the part with small sockets that cradle the gear but go over the shaft. You will figure it out!

OK Cuz…read this out loud I sofa king we Todd did.

After all that fiasco…that wasn’t even the most confusing part. The motor would not fit in the cradle inside the block after I got it all back together.

I was advised to email Navin. So, I did.

He called me and explained that the new Gp40 replacement motors require work to get them to fit. On the side of the cradle that doesn’t have the electronics, there is a tab in front of the “U”, where the output shaft would sit in. That tab has to be removed for the motor to set down flush. Not the acutal “U” itselft, but the part in front of it.

Matt,
Been there, done that. Trimming of the motor cradle is illustrated below:

It’s fortunate you have the GP40 replacement motors as the originals are subject to failing (shorting windings). Aristo-Craft stated they had 1,000 replacement motors available way back when.
See vignette, title: “Aristo GP40 problems - Smoking motors & Debilitated wheels!

-Ted

Ted, I looked forever for a vignette on this, because I just knew you had to covered it at one point. But, I couldn’t find it. I even tried googling it and all that came up was rs3 motor blocks. Thank you for posting the link it makes way more sense than my description!!! I didn’t even think to take pictures of the process.

Hi Matt,

Yeah, finding the vignette of interest can be a problem. Greg E. hosts my vignettes (articles) on his website for me. In addition to the drop downs that can be erratic, Greg organized the vignettes in pages, 10 vignettes per page. It’s probably easier just to look at the “Ted Doskaris’ Vignettes” overall page to see all vignettes listed (81 to date) and click on the one of interest.

Greg also hosts my videos on his YouTube site.

-Ted

Thanks Ted! I saved that direct link to your vignettes! I’ve watched your videos for a long time now!

For those with Aristo GP40’s that don’t know which type motor they have installed, here are a couple photos of the old one and a new one.

The first photo is an old motor that was removed. Notice in the open slot that you can see white plastic on the left.

The second photo is a new type motor after installation. Notice that in the slot you don’t see any exposed white plastic on the left.

Hope this helps.