This is the final part of your ToyBox assembly. Compared to swapping out your output shaft this is a very simple process. Before I get down to the last steps I want to tell you a little bit about what you receive when you order a ToyBox since you receive lots more than is listed on the Marlin Crawler Web site.

I ordered a ”MC24-TB21 (4 Speed) H41/42 with a 4 speed LC Transfercase” I also opted for the lower 4.7 gearset. Each ToyBox is built to order so plan ahead if you have a upcoming trip you are building your truck for. My ToyBox took about a month to reach my door after I ordered. I found this totally acceptable, a week of that was the time it took to travel across the country.

Marlin Crawler numbers all of their adapter plates and gear sets also. I think this is not only pretty cool, but in the event of theft it is very easy to identify your parts if they are recovered. In the install pictures you can make out the numbers stamped into the parts. I am the proud owner of front adapter plate MC24 number 015, rear adapter plate MC21 number 044, and Marlin Crawler 4.7 gearset number 1242.

Whoever packaged my order could train other vendors on how to ship heavy / bulky items. My order arrived in a “Rubbermaid Roughneck” container that had its top zip tied to the base. I was very impressed. After I cut off the zip ties and removed the top I was pleasantly surprised to find I received a bonus shirt and hat with my order! Not only that but the packaging of the parts was amazing. Everything was individually wrapped in dense bubblewrap and the packer had placed the heaviest items on the bottom and the lighter ones on top. I ordered various other items along with my ToyBox so there were alot of items that were in the container. They all arrived in perfect condition.

The container:

The ToyBox parts. In the picture below starting with the round bearing that goes into your transfercase and going clockwise are the four new bolts to hold your transfercase to your ToyBox, the seven bolts to hold the ToyBox plate to your transmission, and the next two bags of bolts hold the crossmember mount to your ToyBox.

New Outputshaft with washer and snapring which can be seen here along with cool Marlin Crawler carabiner keyring.

Speedocable Extention.

Marlin Crawler Shiftknob.

Shifter and boot.

New transfercase gear.

New transfercase seal and gasket.

Tube of quality RTV.

Now lets complete the installation. You must first remove the outer part of the MC24 adapter plate. It is the plate in the left had side of the picture below. It is held on with six bolts that will only be fingertight. You can see these bolts directly above the tape measure in the picture below at 1.5 inches. Remove the three bolts from either side and gently pull the outer plate away from the ToyBox. In this picture you can also see you are adding 6.5 inches to your drivetrain.

This is the ToyBox from the backside which will mate to your transfercase.

Here is a side shot of the ToyBox. Transfercase side is on the left and Transmission side is on the right where you can easily make out the two halves of the MC24 adapter plate.

Here is another side view. In this picture you can also see the Marlin Crawler stamps and numbering and the fill plug for the ToyBox.

This is what the outer part of the MC24 adapter plate looks like. This side of the adapter plate goes toward the back side of the transmission.

The other side of the plate mounts to the ToyBox. Notice the groove that will be filled with RTV to make a seal.

A side view of the plate that bolts to your transmission. You can see the numeric stamps in this picture.

Clean both the adapter plate and the backside of your transmission with brake cleaner and a shop towel to remove any dirt and oil. Then apply a thin bead of the grey RTV supplied around the back side of the transmission just like in the picture below. Don’t lay too wide of a bead! Insert the seven bolts and washers from the (Plate 1 to trans) bag into the adapter plate and screw them in. The factory torque spec for these bolts is (36-58 ft-lb). You can see Toyoda is using the force to hold himself to the side of the transmission. .

In this picture you can see the plate installed onto the backside of the transmission. I have already applied a bead of RTV into the machined channel on the backside of the plate. It is ready for me to install the ToyBox now. Make sure you clean both plate surfaces with brake cleaner to remove any oil or dirt first. You can see the seven bolts holding the adapter plate to the transmission here also.

*Note I have not removed the two terminals from the reverse light switch. Don’t make the same mistake! Remove them before you get to this step! You won’t be able to fit the ToyBox snugly to the adapter with these in place! I had to take out a chisel and deadblow at this point to remove them. Learn from my mistake!

Lightly grease the output shaft splines in the picture and gently slide your ToyBox onto the output shaft. Install the six bolts that hold the MC24 adapter plate halves together and torque the bolts to (36-58 ft-lb). Note: Marlin Crawler does not recommend that you use thread locker on these bolts as they have had instances of the bolts stripping the aluminum adapter plate when people have tried to remove these bolts after using thread lock. I am going to keep an eye on mine to make sure they remain snug. If they do not I am going to apply a drop of wicking light duty thread lock to the back sides of the bolts where they protrude from the adapter plate and if I ever need to remove them I will burn the threadlock first with a propane torch before removal. The low heat from the propane torch will destroy the threadlock but not hurt the bolt or the adapter plate and then I will have no worries about a stripped plate.

Here is the Toybox mounted to the transmission. Note how close the reverse light switch is to the adapter plate. All that is left now is installing the transfer case to the back of the ToyBox.

First clean both surfaces with brake cleaner and a shop towel to remove any grease and dirt. I then applied some Permatex spray gasket tack to both sides of the OEM paper gasket that Marlin Crawler provides. It is red and you can see some overspray on the ToyBox. Stick the gasket to the back side of the ToyBox and lift the transfer case onto the output shaft while holding the transfercase gear in place with your hand through the side of the transfer case. Use the Marlin Crawler supplied bolts to fasten the transfer case to the ToyBox and tighten to the factory spec of (36-58 ft-lb). 

Now install the new Marlin Crawler supplied spacer over the output shaft and then install the new bearing. You will need to drive this bearing onto the output shaft. In the picture below it has been driven into position.

You will now need to install the washer and nut and tighten the nut to the factory spec of (80-101 ft-lb.). You must stake the nut after you tighten it. This nut is 36mm, I had to purchase a socket since I did not own one that large. My local autoparts store had one for $6 in stock since this is the same size as an axle spindle nut on many cars. You will need to make an SST to prevent the transfer case from turning while you tighten this nut.

In the picture below is the SST that I built for this purpose. It is a piece of 1.5” square tube steel that I drilled two holes in that I bolted to the transfer case flange. Without stopping the transfer case from spinning you will not be able to tighten the nut on the output shaft.

Here is the finished product! Note that I also installed a “Marlin Crawler Transfer Case Saver”. In the picture below it is the black piece of steel bolted to the top of the transfer case. Land Cruiser transfer cases have been known to crack and this piece of steel is supposed to help prevent that. There are many vendors who sell a “transfer case saver”. The Marlin Crawler one works with the ToyBox so I added it to my order. I was somewhat bummed that the two holes that attach to the ToyBox were not drilled in the right location and I had to drill them both out quite a bit to make the transfer case saver fit. All the other holes were properly positioned. As a welder I understand how difficult it is to get welded brackets to line up properly but when you are charging over $100 for a couple of welded pieces of steel it should fit perfectly.

I also took this opportunity to remove the factory transfer case breather and replace it with one that I can attach a hose to and run higher up the truck. This new breather is from a 22RE intake, in the picture I have a rubber cap over it to keep out dirt.

Now all that is left is to install it back into the truck, modify the driveshafts, create new transfer case shifters, install a reverse light switch, and make a hole in the tub for the ToyBox shifter. If you would like pictures of the shifter linkages I created with riding lawnmower TREs send me an email. I also built a very simple crossmember to support the ToyBox that will be replaced once I build a new skidplate.

UPDATE: 2007
I have put a few thousand miles on the ToyBox on the streets and highways and two years of trail riding. I have drained the transmission, ToyBox, and transfercase twice in that time and the gearoil was clean, with very little metal dust on the magnetic drainplugs. I can honestly say it is the best modification I have done to improve truck's 4 wheeling ability. The control you have with the ToyBox combined with the stock transfercase allows you to pick your lines and take your time crawling over big obstacles you once had to power over with the skinny pedal. I am running 36" bias IROKs with the stock 4:11 gears in the differentials which gives me great highway RPMs (low). Once I get to the trail I usually use just the ToyBox and only engage the stock transfercase low range when I reach a very tough obstacle that requires more control. The first time you drive up to an obstacle you used to have to power over or ride the clutch to get over you will be smiling ear to ear as you crawl over it. Thanks Marlin!

If you have any questions please feel free to contact me at mailto:fj40smurf@yahoo.com