DHK Maximus (Tutorial with Pics) Stock Bumper R&R Plus Aftermarket T-Bone Bumpers

[MailManX]

NOTE: I originally posted this on a different forum, but I know there are DHK owners who read this forum, so I am reposting here for their benefit.

This tutorial is for someone new to RC’s. An experienced RC owner will already know how to do this. The manual that comes with the DHK is the worst I’ve ever seen. Therefore, I hope this tutorial will be helpful to someone who owns the Maximus and is not used to working on it.

Although the bumpers that come on the Maximus are pretty durable, I did break the rear bumper during an extended bashing session which I posted on YouTube. It broke in two places in addition to breaking the heads off of the lower screws:




The yellow dashed line on the following picture shows you one of the places that broke. This lower tab is probably weakest link. However, there are also screws going through the bumper on either side of that tab and they do a pretty good job of holding it together. This truck must have taken a brutal hit for this to happen.




In this tutorial, I will you show you how to remove and replace a rear bumper. The front and rear stock bumpers on the Maximus are identical to each other, so if you learn how to do one, you can do the other. You can also mix and match parts between them.

In addition to replacing a stock bumper, I will show how to add aftermarket bumpers from T-Bone Racing in Texas. T-bone ships internationally. These bumpers are about the ONLY aftermarket product currently available for the DHK Maximus. In fact, they are not actually marketed for the Maximus. T-Bone lists them as being for the DHK Optimus. However, they fit the Maximus without modification.

Optimus XL

The DHK Maximus, Optimus and Zombie share a lot of common parts. Be sure to keep that in mind when you order replacement parts. This also applies to the Megatron and the Ripmax which are essentially identical to the Maximus.

I currently use T-bone Racing bumpers on several of my other RC’s and really like them. They are made of Delrin which is both tough and flexible. It is also fairly slick, so it slides over obstacles more easily than regular plastic.

Although you can install a T-bone bumper onto the Maximus without using the stock bumper, I recommend leaving the stock bumper on. The T-bone bumper uses different mounting points. With both the stocker and the T-bone bumper in place, you get maximum strength and protection to spread out load impacts.

The following steps will show you have to fully remove and replace all three pieces of the rear bumper assembly in preparation for installing a new assembly.

Remove two screws through the outer face of the bumper:




Removing the 4 screws shown in the following picture allow you to remove the center “spring brace” for the bumper:




Before removing the lower bumper brace, you have the turn the Maximus over and remove the 4 screws on the bottom of the chassis common to the differential case.




The lower bumper brace is held on by two screws that are inset deeply into the plastic. They go through the brace and into the lower frame of the Maximus. Once those are removed, you have to use a flat head screwdriver to pry the aluminum chassis away from the bottom of the differential so you can pull the lower bumper brace out. It has a tab that is fitted into a slot on the chassis.




With the three pieces of the bumper assembly removed, you can pull the upper suspension mount off by hand. If necessary, you can pry it away from the suspension using a flat head screwdriver.




The lower suspension plate is aluminum and is a bit harder to pull off. First, remove the two nuts on the ends of the lower suspension hinge pins. Then, using a flat head screwdriver, carefully pry the aluminum piece away from the suspension.




This shows both upper and lower suspension mounts removed. You are looking at the back of the rear differential.




Since my bumper broke off, the tab was still stuck in place. I used a flat blade screwdriver to pry the aluminum chassis away from the differential case enough to release the tab.




If you ever have broken screws with enough left sticking out to grip with vice grips, I find that is the easiest way to remove the pieces.




They came out with no problem using the vice grips.




To install a new lower bumper support, you need to do it simultaneously with the aluminum lower suspension mount. The easiest way is to push the hinge pins in far enough to get the clearance you need.




Turn the car over and install 2 screws through the lower bumper support into the differential case.




To install the plastic upper hinge mount, line up the pins with the holes then simply press into place with finger pressure.






The center bumper “spring brace” installs with the 4 screws show in this picture.




Attach the final piece of the bumper assembly using 2 screws directly through the face of the bumper.




If you are not planning to install a T-bone aftermarket bumper, then simply install 4 screws into these holes on the bottom of the chassis and you are done. Otherwise, save these holes for use with the T-bone bumper.




Although you can use the stock screws with the T-bone bumper, I recommend using screws about 1mm longer to make up for the thickness of the new bumper.




T-bone makes a standard or wide basher rear bumper. I purchase the basher bumper: DHK Optimus XL bumpers by TBR

The wide rear basher bumper fills up maximum width across the back of the Maximus without interfering with the tires. As you can see from the following pictures, the TBR rear bumper provides much better shock and A-arm protection than the stock bumper would by itself.








This picture shows how well the stock and TBR bumpers work together. Since each uses different mounting points, it makes the back of the Maximus sturdier and spreads out crash impacts.




While I was at it, I decided to add a new T-bone bumper to the front of the Maximus. T-bone makes a standard or wide basher front bumper. I purchased the basher bumper: DHK Optimus XL bumpers by TBR

The next two picture show how well T-bone maximized the width and angle of the wide front basher bumper to just barely clear the tires at full lock steering.






The front and rear T-bone bumpers are similar, but not identical.




Here are a few final pictures of the front and rear of the Maximus with the new bumpers and the body on. This look is probably not for everybody, but I like it. You can’t deny the extra protection they provide.

[Warmntoasty]

Ordered sensei.

[MailManX]

Uh oh! I'm costing you money. That's gonna get me in trouble with your missus.

[Gula]

Those shock towers look like they're on their last leg!! Bent them a few times ?

[MailManX]

Originally Posted by Gula

Those shock towers look like they're on their last leg!! Bent them a few times ?

The front tower holds up well, but the rear takes a beating. Although it is aluminum from the factory, it is quite soft. I can't get the specs on it because DHK doesn't list them. Not much heat treating to it, though. I bent the tower back with large pliers. I wasn't concerned with looks, so did not protect the metal from the pliers so it messed up the anodizing color. That makes the tower look worse than it really is. Although it has a hell of a warp to it now, it continues to do its duty, so I can't complain. I have a couple of spares waiting in my tool kit.

I have an idea in mind for a reinforcing strap that I will post if I ever put it into action.

[Warmntoasty]

Mine arrived yesterday and I installed them just now. They're made of sturdy stuff so will hopefully offer even more protection. The shape of the front bumper didn't conform to the underside of the chassis where the chassis meets the existing bumper but it flattened out once I screwed it in. Hopefully it settles over time rather than placing additional stress on the screws.

Pretty happy with the look and will give it a good bash over the weekend!

[btrc]

hi, i know this is an old thread~ but i just get mine a zombie~ looking for tbr bumper, do you had zombie? are their chassis same? can i install the tbr to my zombie?

[MailManX]

Originally Posted by btrc

hi, i know this is an old thread~ but i just get mine a zombie~ looking for tbr bumper, do you had zombie? are their chassis same? can i install the tbr to my zombie?

The Zombie, Optimus and Maximus all share a common chassis and suspension system. Theoretically, any bumper made for one will fit the other, although some minor alterations may be required. In the case of the Optimus bumpers that I put on the Maximus, I installed them OVER the existing Maximus bumpers and achieved extra strength! Now T-Bone Racing makes bumpers and a wheelie bar specifically for the Maximus. Those did not exist back when I bought my rig nearly 4 years ago!

[btrc]

Originally Posted by MailManX

The Zombie, Optimus and Maximus all share a common chassis and suspension system. Theoretically, any bumper made for one will fit the other, although some minor alterations may be required. In the case of the Optimus bumpers that I put on the Maximus, I installed them OVER the existing Maximus bumpers and achieved extra strength! Now T-Bone Racing makes bumpers and a wheelie bar specifically for the Maximus. Those did not exist back when I bought my rig nearly 4 years ago!

okie, i get it~ Thanks Very very much~ appreciate your reply~ your thread helps me alot~ nice job man~

[MailManX]

Originally Posted by btrc

okie, i get it~ Thanks Very very much~ appreciate your reply~ your thread helps me alot~ nice job man~

You are VERY welcome!