Proto 2000 GP7 truck power and painting question

[BigDaddy]

I bought one off ebay a couple months ago, but I have been busy with benchwork, initial track laying and finally my 1st successful DCC install. 

The GP is undecorrated.  I have never painted a diesel with fan detail.  What color to I paint the fan blades.  Are the handrails made out of that slippery stuff that doesn't take paint?

Second, the seller said he replaced the trucks, for the well known gear cracking problem.  Everyone say there LL 2000's run sweet.  Therefore I was surprised to see that only one side of the trucks is wired.  I don't recall any mention of that in the gear replacement or DCC installation vids I've seen or any comments here about how well they run. 

A google search only found replacing the trucks with Kato and milling the frame.  I'd like to avoid that.  What is the best way to power the opposite side trucks?

 

[gmpullman]

I don't remember which Life-Like locomotives came along with the "improved" pickup where bronze strips were used and the wires were soldered directly to them, maybe when the GP-30s came along? All 8 wheels pick up track power just that one side is carried through the frame.

I have many of the older FAs and GP7s that used the frame to carry half the current pickup. There really isn't anything wrong with that method. I tapped a hole and used a small brass terminal with the decoder wire soldered to it (right now I don't recall which, red or black). I completely remove the light board and use LEDs.

A drop of CRC 2-26 on the contact points and the truck bolster pivot helps maintain continuity.

TCS has some "basic" decoder installs in this list but they don't go into much detail.

http://www.tcsdcc.com/Customer_Content/Installation_Pictures/HO_Scale/HO_Search/search.html

 Some modelers like to use an automotive binder spray that body shops use for plastic bumpers on their handrails. I have found that Krylon light gray primer (sometimes I use white if I'm painting the handrails a light color, like yellow) sprayed in a light coat will adhere well to the "slippery engineering plastic". You still have to be careful with handling. I have locomotives that I have weathered the trucks on maybe fifteen years ago that still look pretty good, and that was just a spray of Polly Scale.

Your model probably has the see-through roof fans. Colors depend on the paint scheme of the railroad. The fan starts out as silver but doesn't stay that way very long, so light gray is probably a good choice for the fan blades. On your undecorated Geep are the fans installed? The grilles were usually body (roof) color.

Newer locomotives had galvanized grilles. The molded air intakes look nice if you give them a light wash with India ink very well thinned.

Regards, Ed

[BigDaddy]

I inadvertently hijacked some guys thread on frogs.  Since I didn't see a second wire coming from the trucks, I assumed no power was sent from one side.  Apparently the frame is the conductor.

gmpullman

Again—

The early Life-Likes used a design similar to that of the Athearn engines. The current path took a route through the TRUCK BOLSTER (as noted) then through the FRAME and on SOME life-line engines (The Alco S-1 for example) was routed directly to the motor brush so there was a possibility of cooking a decoder IF the wheel happened to touch the frame. On the Geeps, FAs, Eriebuilts, C-liners maybe others, there was a ring terminal that continued the current path from the frame and then to the motor brush.

Also why I suggested putting a drop of CRC 2-26 on that bolster contact point. Reduce friction, corrosion and improve continuity.

Therefore one side (four wheels) collect power through the frame and the other side collects from the metal tab you show in your photo.

DID you happen to notice that those metal tabs both collect from the same rail?

So how would the other rail get current to the motor... Ed

I saw the soldering tab, sticking up from the same side of the trucks, but I figured there was wire down in the trucks somewhere that routed the from one side on the front and the other on the back.

For the record, I don't have the newer electric board seen here http://www.tcsdcc.com/Customer_Content/Installation_Pictures/HO_Scale/Life_Like/Proto_2000_GP-9/lifeli2.jpg

Where is this ring terminal you mention?  Maybe it's obvious when I get around to removing the oem electrical board

 

[BMMECNYC]

BigDaddy

The PO said he had a LL GP20  It certainly could be different than my LL GP9. In cardiology, they call it concealed conduction, electrical pathways in the heart you can only imagine.  Maybe that's the case here but I don't see a second wire from my trucks.

EDIT If the frame is the second (concealed) pathway, well I'm glad I brought that up before installing a DCC board, otherwise the kimchee would be deep.

 

 

 

 

 

Yes its a hot frame.  When I plugged the decoder into mine I did not pay attention to that (but I had no issues).  Should be black wire running from both trucks.  Red wire is screwed into the top of the weight.  Engineers side if you are short hood forward.  On the Left hand side (short hood forward) is a red wire going to the lower motor connection.  This is how they get away with hot frame.   Both trucks provide power.

[gmpullman]

BigDaddy

The OP said he had a LL GP20  It certainly could be different than my LL GP9.

Well, for the sake of accuracy what I wrote was:

I don't remember which Life-Like locomotives came along with the "improved" pickup where bronze strips were used and the wires were soldered directly to them, maybe when the GP-30s came along?

Which implies that there was a design change somewhere around that time and there was two wires coming from each truck and the frame was truly isolated.

Between 1999 and around 2003 or so lots of manufacturers were trying to get their version of "DCC ready" locomotives into production. There were lots of variations which involved scratching traces off of PC boards, replacing low voltage bulbs or more commonly, completely gutting the electronics and hardwiring from scratch.

STILL there were holdouts, like the aforementioned Alco S1 which—although having an 8 pin DCC socket—still had a hot frame and the motor + was common to the frame! NOT DCC ready in my book!

I DO have a bunch of Life-Like GP-7s and-9s and I did the decoder installs probably eleven years ago. I don't exactly remember where the screw for the wire on the frame is. I didn't take photos of them back then. 

{edit:}

Looks like this (BLUE ARROW)

Life-Like made many production runs of these Geeps, there are still thousands of them still in boxes! Next month I'll go to a train show here in NE Ohio and I'll bet I see a dozen vendors selling them along with many varieties of E units, PAs, FAs and on and on.

They made several design changes during their long production run so there might are  variations, and then there's more changes that Walthers did after THEY took over the line.

The best method for a decoder install in nearly any locomotive is to strip it down to the basics, get rid of any existing PC board with useless diodes. Study how the rail power is collected and how the motor is fed. 

In its very basic form there are only two paths from the rail to the motor. All you're doing is breaking that path then inserting a decoder between the two end points.

Can it be any easier?

Good Luck, Ed

[BMMECNYC]

gmpullman

 

BigDaddy

The OP said he had a LL GP20  It certainly could be different than my LL GP9.

 

 

Well, for the sake of accuracy what I wrote was:

I don't remember which Life-Like locomotives came along with the "improved" pickup where bronze strips were used and the wires were soldered directly to them, maybe when the GP-30s came along?

Which implies that there was a design change somewhere around that time and there was two wires coming from each truck and the frame was truly isolated.

Between 1999 and around 2003 or so lots of manufacturers were trying to get their version of "DCC ready" locomotives into production. There were lots of variations which involved scratching traces off of PC boards, replacing low voltage bulbs or more commonly, completely gutting the electronics and hardwiring from scratch.

STILL there were holdouts, like the aforementioned Alco S1 which—although having an 8 pin DCC socket—still had a hot frame and the motor + was common to the frame! NOT DCC ready in my book!

I DO have a bunch of Life-Like GP-7s and-9s and I did the decoder installs probably eleven years ago. I don't exactly remember where the screw for the wire on the frame is. I didn't take photos of them back then. 

{edit:}

Looks like this (BLUE ARROW)

Life-Like made many production runs of these Geeps, there are still thousands of them still in boxes! Next month I'll go to a train show here in NE Ohio and I'll bet I see a dozen vendors selling them along with many varieties of E units, PAs, FAs and on and on.

They made several design changes during their long production run so there might are  variations, and then there's more changes that Walthers did after THEY took over the line.

The best method for a decoder install in nearly any locomotive is to strip it down to the basics, get rid of any existing PC board with useless diodes. Study how the rail power is collected and how the motor is fed. 

In its very basic form there are only two paths from the rail to the motor. All you're doing is breaking that path then inserting a decoder between the two end points.

Can it be any easier?

Good Luck, Ed

 

Get rid of the Light BULBS!

Dont remember which bulbs where in the GP, but LEDs are an easy upgrade due to LL using a Light tube (At least my MEC GP7 Does).  If the bulb is one of the 3/16" (approx) sized ones it needs to go in the trash.  Can easily turn your well detailed plastic shell into molten slag.

[BigDaddy]

Thanks guys, I've been at the Ocean, at a hotel with 300 baud Internet.  Well they called it wireless.  Thumbs up for wireless.

[BigDaddy]

It's an old thread but it's mine and I'm bringing it back  My engine has been parked on Procrastination Junction. 

Unlike the above pics, there  is no red wire attached to the weight.

WH 1 & 2 both come from the left sides if the bank and short hood trucks.

M+ red wire to motor

M- is a copper tab that extends below the board to contact a copper strip above the engine

RL's and FL's are for the lights. There are soldering pads P1-8 except I'm not seeing P3.  P7 is soldered to a couple resistors?

There is also a "cut here for DCC"

My intention is to install a loksound micro decoder in place of this circuit board, install LED's instead of the bulbs and alter the weight for a cell phone speaker.  This is only my second DCC install, so I have a lot of trepidation. 

I assume much will be revealed when I unmount the weight.  In the meantime, would the right side trucks connect to both the motor and circuit board via M- ?

What are all these P pads for?

I am assuming the Cut here for DCC is about the voltage to the lights, but how would a decoder mount to this board (not planning on going that route)

[rrinker]

That big hole bottom center, to the left of the P7 marking - does a screw go in there? That looks like where it picks up from the frame, since the whole has a copper ring around it for contact with a screw head. Plus that very trace leads right to one of the "cut for DCC" X's. The motor minus is going to be a clib soldered to the circuit board (looks riveted on, actually) at the M- hole right center of the circuit board.

P pads I used to train my dog when she was a puppy.   Actually, I think if the X's are cut those are supposed to correspond to the 8 pins on the DCC connector. Do yourself a favor, just completely remove that board for the install. Since it uses a clip to the top motor connection you may need to solder a wire to the top brush holder. Since there is a wire going to the lower brush the motor most likely is isolated from the frame but double check so as to prevent frying the decoder.

                                --Randy

 

[BigDaddy]

The two round holes are screw holes. (screws removed before I took the pic)

rrinker

Since there is a wire going to the lower brush the motor most likely is isolated from the frame but double check so as to prevent frying the decoder.

This is just a straight forward continuity test?  (looking for ways to avoid screwing up)

[BMMECNYC]

BigDaddy

The two round holes are screw holes. (screws removed before I took the pic)

 

 

rrinker

Since there is a wire going to the lower brush the motor most likely is isolated from the frame but double check so as to prevent frying the decoder.

 

 

This is just a straight forward continuity test?  (looking for ways to avoid screwing up)

 

Yes and no.  

Place locomotive on a dead piece of track.  Check continuity between rails and frame.  When you get a beep, remove probe from rails while maintaining contact with frame.  Touch probe to bottom motor wire, if it beeps, you have an issue, if not, should be fine.  

Alternately you can unscrew the weight and remove motor (either screw or those rubber mount press fit in).  Carefully remove the drive shafts by pulling away from but in line with the flywheels (they should be telescoping).  

If rubber mount, rock motor side to side and end to end while pulling up, may need to apply pressure to the bottom four holes.  If screw mount it should pull out somewhat easily. 

Once motor is out, place a piece of electrical tape on the frame at the centerline of the locomotive.  Check to make sure that the motor doesnt have one of the frame pickup tabs on it (it shouldnt if there is a wire going to the lower motor contact).  Look at the solder joint between the lower motor wire and the frame while you have it out.  If it leaves something to be desired, you may wish to re-solder it while it is out. 

IF you remove the contact clip from either side of the motor, take care not to loose the motor brush and brush spring (spring is slightly compressed, and if you just pop the clip out it may launch into orbit).  

If you get this far, you may find it desireable to clean the trucks and re-lube with Labelle products.  I have found most of the models that I get from factory are excessively lubricated, even new old stock.  Walthers and LL P1k/2k particularly.  Had an P1k RS2 that would not run at all due to dried up grease in the gearbox.

Reverse process to reassemble.

 

[BMMECNYC]

BigDaddy

I assume much will be revealed when I unmount the weight.  In the meantime, would the right side trucks connect to both the motor and circuit board via M- ?

The answer is kind of to first part, second part no.  The M- just contacts the motor contact clip on top.  

Right side trucks feed power via the bolsters directly to the frame.  The copper ring contacts around the lighting board are the give away.  Right side truck power feeds througth the weight to the board.  

If you can find a ring terminal small enough (I think that is what they are called), you can immitate the photo that Ed? posted that has the arrow.  If you cant find one, you can make one with a small brass washer by soldering a wire to it.

[santafe5000]

I have been working on a Proto2000 GP60 which was in the same time frame as the GP7. There is only one wire from each truck, on the left side. The frame, via the bolster is the electrical path for the right side. I too have a wire attached via a small ring terminal to the top of the weight for right side connection. The fuel tank is held on by a strip of double sided tape which had through all these years become a strip of GOO. It took soaking the frame in an alcohol bath to remove it from the frame.

There are two large screws next to the motor mount tabs which in conjuction with the two small screws at each end of the frame which hold the weight to the frame.

The motor mount plastic tabs on my unit were the white type, but were hard from age. They broke off from the bottom of the motoer when i rocked them side to side to remove the motor from the frame. The standard Athearn screw mounts fit perfectly, so i will replace with them.

There was another strip of gooey double sided tape running along the bottom of the lower motor brush retainer, that would ensure the motor was isolated from the frame. I replaced with a strip of Kapton tape.

The tiny ring terminal on the top of the weight was broken loose from its connection,, so i used one of the PCB mounting screw holes to reattach it. Chunked the PCB board and wired in a JST plug to the associated wires and installed  DH142 decoder. And replaced the bulbs with LEDs.

[GrandTrunk-HO]

Proto 2000 Diesel Locomotives (HO) Scale

BigDaddy

September 04, 2016

I bought one off ebay a couple months ago, but I have been busy with benchwork, initial track laying and finally my 1st successful DCC install. 

Second, the seller said he replace the trucks, for the well known gear cracking problem.  Everyone say there LL 2000's run sweet.  

Therefore I was surprised to see that only one side of the trucks is wired.  

I don't recall any mention of that in the gear replacement or DCC installation vids I've seen or any comments here about how well they run. 

A google search only found replacing the trucks with Kato and milling the frame.  I'd like to avoid that.  What is the best way to power the opposite side trucks?

I presently have over (10) Proto 2000 diesel locomotives, from Life-Like first release, till Life-Like last release, before Walthers Trains took over this product line.

Sorry to inform you, but this Ebay seller was (100%) incorrect informing you to replace the trucks, for this well-known gear cracking problem.

When I checked my Proto 2000 diesel locomotives, (85%) of the drive axle gears were cracked. (faulty manufacturing using the incorrect type of plastic). This faulty drive gear will not rotate the locomotive axles.

 

To repair my Proto 2000 diesel locomotives, it only required that all the locomotive drive axle gears be replaced. A very simple procedure and no special modifications were required.

I used Athearn #60024 gears to replace my LL cracked drive axle gears that are exactly the same size.

Part# ATH 60024 Loco Drive Axle Gear - SD40-2 - 6 per pack

 

[BMMECNYC]

GrandTrunk-HO

Sorry to inform you, but this Ebay seller was (100%) incorrect informing you to replace the trucks, for this well-known gear cracking problem.

The seller did the replacement, did not instruct buyer to do any replacements.

BigDaddy

Second, the seller said he replaced the trucks, for the well known gear cracking problem.

 

[GrandTrunk-HO]

BMMECNYC

 GrandTrunk-HO

Sorry to inform you, but this Ebay seller was (100%) incorrect informing you to replace the trucks, for this well-known gear cracking problem.

  

The seller did the replacement, did not instruct buyer to do any replacements.

 BigDaddy

Second, the seller said he replaced the trucks, for the well known gear cracking problem.

 

 

Sorry, but I am confused. Are we talking about “trucks” or “drive axles?

[BigDaddy]

GrandTrunk-HO

Sorry, but I am confused. Are we talking about “trucks” or “drive axles?

It's been a year since I bought the thing on Ebay.  The original ad is gone.  I may have mispoken or the buyer may have.  I was trying to forstall the thread moving off to gear replacement and lubrication.  Looks like I failed.

[GrandTrunk-HO]

BigDaddy

GrandTrunk-HO

Sorry, but I am confused. Are we talking about “trucks” or “drive axles?

It's been a year since I bought the thing on Ebay.  The original ad is gone.  I may have misspoken or the buyer may have.  

I was trying to forestall the thread moving off to gear replacement and lubrication.  Looks like I failed.

Hello: Henry (BigDaddy)

No problem at all, because Proto 2000 diesel locomotives require the drive axles to be replaced. (cracked plastic gears).

I myself have never seen any detailed information about lubrication, when it comes to Proto 2000 locomotive diesel drive assembly mechanisms.

I presently have over (10) Proto 2000 diesel locomotives, from Life-Like, till Walthers Trains took over this product line.

(1st) Life-Like First Release = Tan Colored Boxes

(2nd) Life-Like Second Release = Blue Colored Boxes 

(3rd) Life-Like Third Release = Silver Colored Boxes 

I removed the bottom cover plate from a locomotive drive assembly. This is exactly what I have found. Of course there is the obvious cracked axle drive gear. I was shocked to find that some of the internal gear drive assemblies had gear lube that has dried out. (plugging up the gears). This will also cause the internal gears not to rotate smoothly, especially at slow speeds.

Looking at the actual posted image (below), there is actual yellow dried out gear grease.

Gear Grease: 

It is used so the lubricant stays on the gears. It is also a thick lubricant used on very small gears. Also has a limited usage time till it breaks down or dries out.

Gear Jel: 

It is used so the lubricant stays on the gears. It is also a jel like lubricant used on very small gears. Also has a limited usage because I used this type of product and in time the jel turns into a liquid.

Gear Oil: 

It will tend to slowly drop off the gears. It is also a thin lubricant that is ideal on very small gears. I use gear oil because no future internal gear cleaning will be ever required. When doing required locomotive maintenance like cleaning the drive wheels, remove the bottom cover plate from the locomotive drive assembly and only add a drop of oil onto each internal gear.  

Here are some of the top gear oil sellers.

* Woodland Scenics Hob-E-Lube WHL654 Lite Oil

* Bachmann E-Z Lube #99984 Light Gear Oil

* Labelle #102 Medium Viscosity Gear Lubricant

* Bachmann E-Z Lube #99983 Heavy Gear Oil

* Best Choice --> Woodland Scenics Hob-E-Lube HL655 (tough, long-lasting, heavy-duty, with tack additive for anti-drip adherence) 

http://woodlandscenics.woodlandscenics.com/show/Item/HL655/page/1

Warning:

Be sure that all the internal gears are (100%) clean from any dried on grease, before adding any type of gear lubrication.

My Recommendations:

I use gear oil because I will “never” be required to totally rebuild and clean the internal truck drive assemblies.

 

[GrandTrunk-HO]

Optional Replacement Parts

Walthers Replacement Drive Axle Gears pkg(6)

Walthers Part # 116-40005

 

Walthers Proto Geared Drive Assembly

Walthers Part # 920-584408

Replacement Geared Driver Assembly (Diesel Wheelset) pkg(2) -- For Early PROTO 2000(R) BL, FA, GP7/9/18/20/30/60 & PROTO 1000(TM) F3,RS2,RSC2

Walthers Proto Geared Drive Assembly

Walthers Part # 920-584494

Replacement Geared Driver Assembly (Diesel Wheelset) pkg(3) -- For Early PROTO 2000(R) E6/7/8/9

My Assembly Procedures

Each individual Proto 2000 drive axle consists of (5) components.

 

For the locomotive drive axles to operate correctly and very smoothly, I use a NMRA Standards Gage (HO Scale). To check for the correct wheel flange distance at the (2) notches marked "WHEELS".

 

Also for the locomotive drive axles to operate correctly and very smoothly, the square bronze bushings must spin freely. I use a feeler gage set. This will insure that all (4) required gaps on the drive axle will be all the same. I use a feeler gage set that has a round nut on it, so all the shims can be removed.

I use regular, none tapered shims. (26 shims = 0.0015" inch to 0.025" inch)

 

Since the (1) plastic drive gear is molded and the (2) square bronze bushings are casted, there will be different equal gap sizes for each individual drive axle.

This is the easiest procedure I presently use to have the (4) required equal gaps.

(#1)

I totally assemble (1) complete drive axle. Then I press it together, not allowing any open gaps. 

(#2)

I always hold the plastic drive gear, while I slowly "only" adjust (1) wheel location. I use the NMRA gage to check for the required correct "WHEEL" distance.  

(#3)

Where I "only" adjusted the (1) wheel location, I push the square bronze bushing up against the plastic drive gear. Using the feeler gage set, I measure this open gap, stacking shims together and record the measured value.

(#4)

For example I got a .062" inch total gap measurement at only (1) location. Require (x4) equal spaced gaps. I now take the (1) total .062" gap and divide it by (4). For (4) equally spaced gaps will require (4) .0155" shims. In this case the mid range is .016". I would use (4) different shims, .014", .015", .016", .017" = .062" in total.

(#5)

I now slightly pull out the opposite wheel so there are now (4) open gaps. I also found it very difficult to hold the (4) different shims at the same time.

Using plaster scene, I make a square block that holds the (4) different shims, roughly in the required locations. I place the (4) required shims into the (4) required gaps.

Then I press the complete drive axle assembly together, making sure that there are (4) open gaps from the shims. 

(#6)

To insure that this locomotive drive axle will operate correctly and very smoothly, I use the NMRA gage to check each locomotive drive axle.

 

[BMMECNYC]

BigDaddy

 

 

GrandTrunk-HO

Sorry, but I am confused. Are we talking about “trucks” or “drive axles?

 

 

It's been a year since I bought the thing on Ebay.  The original ad is gone.  I may have mispoken or the buyer may have.  I was trying to forstall the thread moving off to gear replacement and lubrication.  Looks like I failed.

 

It is unfortunate.  Was I able to answer your internal wiring questions?  Did my post leave you with further questions?

[BigDaddy]

BMMECNYC

Was I able to answer your internal wiring questions?

Thank you for your help.  I got sidetracked with my F&C gondola and that I need to get in touch with a friend who has a milling machine to make room for a speaker.  I'm sure I'll be able to get it wired up correctly.  I'll be back when I get it done.

[BigDaddy]

BMMECNYC

Alternately you can unscrew the weight and remove motor (either screw or those rubber mount press fit in). Carefully remove the drive shafts by pulling away from but in line with the flywheels (they should be telescoping). If rubber mount, rock motor side to side and end to end while pulling up, may need to apply pressure to the bottom four holes

Edit (16:44 edt)   I finally mustered up the courage to try this.  I'm trying to remove the engine to make sure there are no surprise points of contact.

These rubber plugs, are they attached to the engine and mushroom out the bottom of the gas tank. I boogered one up pushing it out

If that grease was in my motorcycle tranny I'd say water got in there.  For those that don't know, that is the worm cover, upside down, just to show the color of the grease.

The truck cover (bottom) came off but I don't see how it is possible to disassemble it any further.  When people say they add a second wire to the trucks for improved pickup, where are they doing it?  I suppose you could solder it to the outside.  I don't want to chance melting the gears though.

As you can see, the insulating tape is starting to wear thin in one corner.

The grease is not like coffee and milk, it is like peanut butter.

[BMMECNYC]

BigDaddy

 

 

BMMECNYC

Alternately you can unscrew the weight and remove motor (either screw or those rubber mount press fit in). Carefully remove the drive shafts by pulling away from but in line with the flywheels (they should be telescoping). If rubber mount, rock motor side to side and end to end while pulling up, may need to apply pressure to the bottom four holes

 

 

Edit (16:44 edt)   I finally mustered up the courage to try this.  I'm trying to remove the engine to make sure there are no surprise points of contact.

These rubber plugs, are they attached to the engine and mushroom out the bottom of the gas tank. I boogered one up pushing it out

If that grease was in my motorcycle tranny I'd say water got in there.  For those that don't know, that is the worm cover, upside down, just to show the color of the grease.

The truck cover (bottom) came off but I don't see how it is possible to disassemble it any further.  When people say they add a second wire to the trucks for improved pickup, where are they doing it?  I suppose you could solder it to the outside.  I don't want to chance melting the gears though.

As you can see, the insulating tape is starting to wear thin in one corner.

The grease is not like coffee and milk, it is like peanut butter.

 

Yeah thats pretty typical for the grease.  You might see if athearn motor mounts are available, they have a version the screws in insteand of press fit.  They might work, as this is an athearn clone drive.  You will need a washer or a pan head screw with a wide enough head to simulate the rubber stub that held the motor in place.  Isopropyl Alcohol and q-tip does wonders for getting rid of the grease. 

The trucks do come apart, but it is sort of a pain to get there (involves removing an easily broken clip on the bottom of the truck).  Once removed the side frames should pull out then the gear box halves should come apart with little or no force (there might be a screw or two involved with taking the gearbox halves apart).