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Note: This build log is excerpted from my web site . You can check there for larger versions of every photo or further reading.

The 58060 Monster Beetle was originally released in 1986 and was based on the 58058 Blackfoot chassis released only a few months earlier. This, in turn, was an evolution of the earlier ORV chassis used on the 58038 Subaru Brat in 1983 but now with more suspension travel. The Monster Beetle was re-released in 2015 as 58618 which is the version that I have. The primary difference is an improvement to the durability of the gearbox.
This is rear wheel drive, simple monster truck chassis. The front suspension is independent with extremely durable control arms and radius arms. The rear suspension is an unusual independent trailing arm type which is actually similar to how the original Volkswagen Beetle worked. The motor is located in the rear above the gearbox which contains a plastic gear differential, the weakest point in the model. The motor position cannot be adjusted, so only the included specialized 10 tooth pinion can be used. It is brass and therefore the set screw threads can be stripped quite easily which happened to me. The chassis is a simple two piece space frame which is very strong. The steering servo is buried inside the front of the frame at an angle and is very well protected. The radio gear sits atop the frame. The 4 oil filled CVA shocks are molded in yellow, and the rear shocks are mounted on cranks connected to the trailing arms and are installed longitudinally. The kit includes a mix of ball bearings and metal bushings. Surprisingly for an entry level product, the drive shafts are nice CVD units. The battery installs crosswise under the frame and is trapped by a pair of brackets so only a 7.2V NiMH or something of equivalent size fits. I managed to squeeze in a Li-Po by using a Dremel on one of the battery brackets.

The real highlights of the kit are the tires and body. The tires are large studded rubber without any foams making the car (truck?) very bouncy. The gold plated wheels look really nice. The body is a hard plastic shell originally from the 58016 Sand Scorcher all the way back in 1979. Despite the molded lights, there are no light buckets provisioned for LEDs. The body is mostly open inside, but features a driver figure with only an upper torso suspended from the inside of the door panel. There is a transparent part which serves and windscreen and side window, but the rear window is left wide open for some reason. The body looks really good with the included stickers.

This model is a blast to drive. The stock gearbox is super noisy and the suspension is bouncy, but the drive is pure joy. It is not particularly fast, does not corner that well, and is certainly not a crawler but on gravel, grass, or sand it excels. My copy was stock for a long time, but it is not my way to leave it that way forever. I eventually moderately upgraded to a ball differential.

I was having so much fun building this that I hardly took any pictures. The following show the mostly completed chassis.

The front suspension uses vertical shocks attached to a shock tower, but the control arm arrangement is somewhat unusual. The upper and lower control arms are simple rectangular links while the thrust loads are carried by a wire radius arm. The spindle does not have any bearings and does not rotate. Instead the bearings and hub are located inside the wheel.
The rear suspension is an independent trailing arm type. This means the wheel swings through a wide arc that needs to be accommodated by the drive shaft. The shocks are attached to crank arms on the axle housings. The rear axle joints are protected by flexible rubber boots.
The rear gearbox has metal plate sides and holds a plastic gear differential and an idler gear. The motor hangs from the top of the gearbox and cannot be adjusted. At neutral suspension compression the drive shafts are at a large angle which makes them quite noisy.
From the bottom you can see how the battery is installed. There is a battery hatch which is latched with a white pin. The battery is trapped from moving side to side by a pair of brackets. The battery is the low point on the vehicle and is completely exposed, so you need to use something durable. I use either a NiMH or a hard pack Li-Po, but the latter only fit by trimming away part of one of the brackets.
From a bit further back you can see the two piece red space frame chassis and the black plastic dust cover which slightly protects the servo. The ESC and receiver and almost completely exposed up above. Although the body will later cover them, it has no rear window and therefore they are exposed to the elements. I suppose they are well cooled though.
Here's the final buggy with the body attached. There is a regular vertical body post in the front, but in the rear the body posts stick out the side. The body rattles around like crazy as you drive.

Here's my little pile of upgrades for the Monster Beetle. Nothing too fancy, I just wanted to upgrade the speed a bit. You don't want to go too far or the brittle chassis plastic will just break.
The stock differential, while better than the 1986 original, is still loud and not very strong. The spider gears are housed within a nylon spur gear. I decided to replace the whole thing with a MIP ball differential which is super strong and quiet. It is a direct drop in. You can see the before and after parts below.
After installing the ball diff, the next upgrade is to the silver can 540 motor. I replaced it with a 23 turn Tamiya Super Stock BZ motor. Even though the difference is only from 27 to 23 turns, this thing makes a huge difference in performance. It also has replaceable brushes.


This shows the final before and after. You'll notice I replaced the stock ESC. Even though it was rated to support up to 23 turn motors, I found that it cut out a lot especially when going into reverse so I swapped in a Hobbywing 1060 ESC which works much better.
During the initial build I also replaced all the stock plastic bushings with ball bearings. You can get ball bearings so cheaply that I'm amazed any kit still comes with bushings.

Update: About a month later I went back and reverted to the original motor and speed controller. This chassis is just not up to any more speed. I found a "Torque Tuned" motor in my box and used that.

I wanted to mimic the box art so I went with classic TS-49 Bright Red. The stickers are all right off the box art as well. This was the first drive figure I had ever painted and I can't say I did a very good job. His eyes are particularly disturbing. Don't look into them. Other than that it came out beautiful. If you happen to do any wheelies or jumps the rear license plate is liable to get knocked off which has happened to me several times.
One thing that surprised me about this chassis is the type of plastic used. Tamiya uses a wide variety of plastics in their models. Sometimes very soft types are used for control arms or parts which will take a lot of shock. Very hard types are used for shock towers. Often fiber reinforced types are used where high strength is needed. The red space frames in this model are a very hard, brittle type of plastic which seems particularly ill suited to structure. It can easily crack just from tightening the screws.

I've heard that the original Sand Scorcher body had a rear window but the re-re Scorcher, MB, and Blitzer Beetle do not. Was the original part connected to the side windows or a separate part? Is there any way to still get one?

blakbird wrote:

I've heard that the original Sand Scorcher body had a rear window but the re-re Scorcher, MB, and Blitzer Beetle do not. Was the original part connected to the side windows or a separate part? Is there any way to still get one?

Scorchers of any vintage don't have rear window "glass", it would block off access to the rear body mount clip.

I didn't know the re-re Blitzer and Monster Beetle don't have rear window glass - the originals did, it was just a continuation of the moulding, so four sides rather than a squared off "U" shape. I've never looked for an original tinted 4-sided window part so couldn't say for sure, but my guess is that it'd be rare & very expensive for a perfect one.

Sounds like I should just use a scrap bit of Lexan. In my opinion, the Monster Beetle looks a bit off without a rear window. Your point about the Sand Scorcher makes sense.