DHK Maximus - Help needed !

[Quai18]

Hi everyone !

I am a newbie here, I got my first RC about one year ago.

I made quite a lot of research, and I wanted to buy an Arrma BLX (kraton, and then Outcast), but the prices were too high for me, and I thought I should get something cheaper as a first RC.
Therefore, I bought a DHK Maximus because I thought it was the best RC I could get for less than $300.
Very similar to the DHK Zombie, but wider, better ESC (120A), 2x 2S batteries from stock, and myabe some improved part here and there (no problem with Differential outdrives for the moment).

Quite happy with it, but if I could do it again, I would buy a Granite BLX : awesome truck for the money !!!

Anyway, maybe I will sell my DHK Maximus soon to buy the Granite BLX, but I have a problem I need to fix before. My Maximus is making a strange noice when braking. Noise (seems to) come from the front diff. I recorded a video but we can't hear much... In real, the noise i very loud, sounds like some pinion or something isn't working as it should. Here is a link to the 2 videos I made : https://photos.app.goo.gl/3Mf5tY5KdF8edRC66
I hadn't got this noise before, and there is no noise if I do the same (accelerating, and then braking) with the front wheels off the RC.

What do you think ?

If I need to open the front diff and change something, should I also put some new oil in the front diff ? If yes, should I then put/change oil on all diffs ?
I was searching a lot, but the recommendation on RC forums are from 10k to 50k for the front, 30k to 120k in the middle, and 5k to 60k in the rear diffs.
Would go in the middle if I need to, like 30k in the front, 100k middle, and 30k rear. Does it sound OK for you ?
Any recommendation ?

Thanks a lot !

 

[bicketybam]

Sounds like the mesh between the pinion and ring gear is bad, probably due to damage to one or both of those gears. When you get off the throttle the tirea just stop spinning. That's never good. I'd pull the diffs and check those gears. Good chance you are missing teeth.

 

[Jerry-rigged]

In the vid, you are hitting full brakes to stop the wheels, right?

I think I hear a bit of gear noise when you hit the brakes. My guess is the front diff is wearing out. (I have this on my Kraton when the diffs get old - the front diff starts to slip / pop while braking). You may be able to shim it to get a bit more life out of it, but really, it will need a new ring and pinion. When you put the new gears in, be sure and shim the diffs, so they will last a bit longer next time. For the proper shim size, find the OD of your diff output bearing, and get a shim with the same OD. Start with one shim on the outside of the bearing on the ring gear side of the diff.

Good luck!

 

[Quai18]

Thanks a lot for your replies.
Yes, I am hitting full brakes to stop the wheels.
Not sure I understand 100% what I have to do, but I guess opening it, changing the dammaged part, and closing the diff box after putting some proper oil will do it
I think this RC comes with only bad quality grease in the diff, so I will have the opportunity to fill them with proper diff oil. Thinking of 30-100-30.
Should be OK, no ?

Thanks again

 

[Jerry-rigged]

For 4s running, those oils will probably be fine.

Read this thread, and watch the vids. Some minor details will be different for your truck, and the part numbers for the shims will likely not be right, but it will give you an idea of what to expect.

 

[Quai18]

Also, do you know what it the name of the part at the bottom of this image ?
I changed the oil in my shocks, but these parts where torn up on 3 of my shocks. It is the soft rubber part on the top of the shock, inside, which is making the shock damp-proof. I can buy the original set, but looking for a stronger/ more reliable alternative (diam is 12mm I think)

 

[bicketybam]

In the vid, you are hitting full brakes to stop the wheels, right?

I think I hear a bit of gear noise when you hit the brakes. My guess is the front diff is wearing out. (I have this on my Kraton when the diffs get old - the front diff starts to slip / pop while braking). You may be able to shim it to get a bit more life out of it, but really, it will need a new ring and pinion. When you put the new gears in, be sure and shim the diffs, so they will last a bit longer next time. For the proper shim size, find the OD of your diff output bearing, and get a shim with the same OD. Start with one shim on the outside of the bearing on the ring gear side of the diff.

Good luck!

I thought he was just letting off the throttle, lol. It sounded pretty lound and grind to me.

 

[Jerry-rigged]

Yeah, I think the grind is the issue he is asking about.

Also, do you know what it the name of the part at the bottom of this image ?

That is called a shock bladder.

 

[Quai18]

For 4s running, those oils will probably be fine.

Read this thread, and watch the vids. Some minor details will be different for your truck, and the part numbers for the shims will likely not be right, but it will give you an idea of what to expect.

Thanks a lot !
So I got into the diff and the pinion gear is used.
I will buy a new one and try to find some shims that work.
Really thank you so much: I learned a lot by following your link and instructions !

 

[Quai18]

Well, I've finally invested ?
I bought an Arrma Outcast V3, second hand but it is like new ?
I have a few small repairs to go over on the Maximus and then I will sell it.
Next will probably be the Typhon, that I will Truggified : easier to work on the same brand vehicles. But I will wait on the new 2019 Arrma releases, it could change my mind. Anyway I want a smaller rig than the Outcast, so I will see what's next.
I have also bought the LWB chassis on JennyRC to try out the Kraton one day, by just swapping all the pieces from my Outcast. Still need the rear chassis brace and dogbone.

 

[slick2500]

Well, I've finally invested ?
I bought an Arrma Outcast V3, second hand but it is like new ?
I have a few small repairs to go over on the Maximus and then I will sell it.
Next will probably be the Typhon, that I will Truggified : easier to work on the same brand vehicles. But I will wait on the new 2019 Arrma releases, it could change my mind. Anyway I want a smaller rig than the Outcast, so I will see what's next.
I have also bought the LWB chassis on JennyRC to try out the Kraton one day, by just swapping all the pieces from my Outcast. Still need the rear chassis brace and dogbone.

When you say smaller how small are we talking here?

 

[Quai18]

When you say smaller how small are we talking here?

Well I am sure I want to stick with Arrma, and almost sure I want to stay with a solid rig (aluminium chassis, tower, shocks...) so the Truggified Typhon is the best bet at the moment...
I like the Proline MT 4x4 as an exemple, or the Arrma Siren by TP-Parts ? so I guess 1/10th is what I am looking for.
I still want to have the ability to go on every kind of terrain, and the Truggified Typhon seems to be very versatile just by changing the wheels (MX28 for all terrain, Jconcept G-locks as Rich's for street and drift...)
Vas (Aussie RC Playground) was talking about possible 1/18th, but I don't know how small it can be... Never saw one in real, but I think too small.
Or maybe the "to be released" Outcast or Kraton 4S could be the answer, if they are tougher than the 3S rigs, or if the parts are (really) available at launch.

Do you have any suggestions ?

 

[slick2500]

The HPI Savage XS Flux, it is massively overpowered out of the box and kind of a pain to work on do to the TVP design. This uses standard roar sized batteries. https://www.amainhobbies.com/hpi-sa...YUnjV5zCtuacwoGYFJQnlMSPN8AfsStQaApidEALw_wcB

LC Racing EMB-MTH/Tacon Valor, the radio that comes with the rtr version is kind of on the small size but it is light and feels good in the hand and it alone is definitely worth the extra $15 over the ARR version, the nimh battery that comes with the rtr is kinda meh only 1100mah. This uses mini batteries and the stock battery holder is rather small so it limits the size of battery you can run. I ditched the stock battery hold down and went with one of these that I trimmed down https://www.amainhobbies.com/purete...ck-mount-strap-black-medium-pur022-bk/p146382 I also put some Velcro on my batteries as this mount uses Velcro as it's base, really nice stuff. Parts for these can be found in quite a few places Warren Rc, Nitro RCX(under the Tacon brand), rcmart and eBay. Whatever you do DO NOT buy the brushed models, they are not worth it at all. http://casterracingmi.com/index.php?route=product/product&path=173&product_id=1854

Just a size comparison from left to right Arrma Outcast, LC Racing EMB-TGH(LWB) and what started it's life as a Tacon Valor turned into an LC Racing EMB-MTH.

 

[Quai18]

Wow thanks a lot for the detailed advice !
But if I was OK about having 2 different brand rigs, which means different parts, different layout etc, I would probably just keep my Maximus. So next will be an Arrma ? !

 

[slick2500]

Wow thanks a lot for the detailed advice !
But if I was OK about having 2 different brand rigs, which means different parts, different layout etc, I would probably just keep my Maximus. So next will be an Arrma ? !

Having more than one brand isn't a bad thing. I have cars from Arrma, Axial, Ecx, HB Racing, LC Racing, Team Associated and Traxxas.

 

[Quai18]

I am sure it isn't but I am new in the hobby so at the moment 1 brand seems more manageable ! ?

 

[Quai18]

@slick2500
Ah and one last thing, I have found a deal close to my home: 2x Tekno MT410. One is brand new but already assembled, the other is an used one (this last one is sold without the shocks, and may need some repairs), 350 USD for both. Without any electronic or tyre of course. I think it is a good deal, but I have read that some people still prefer Arrma, and the MT410 needs some upgrades to be as tough as the Arrma, even if some components are better quality.
What do you think ?

 

[bicketybam]

@slick2500
Ah and one last thing, I have found a deal close to my home: 2x Tekno MT410. One is brand new but already assembled, the other is an used one (this last one is sold without the shocks, and may need some repairs), 350 USD for both. Without any electronic or tyre of course. I think it is a good deal, but I have read that some people still prefer Arrma, and the MT410 needs some upgrades to be as tough as the Arrma, even if some components are better quality.
What do you think ?

The Tekno is a really good platform. Rock solid and as tough as Arrma for sure (if not tougher).

 

[Bri26]

I would say the Tekno is tougher than ARRMA. It's the ProLine MT 4x4 that needs some upgrades to be as tough as an ARRMA.

Another really good option is the Team Redcat TR-MT10E, it's definitely in the top 3 as far as 1/10 scale 4x4 RC monster trucks. If you want to run 3s, then it's best to get the optional center diff and fill it with 300K diff fluid.

Brian

 

[slick2500]

@slick2500
Ah and one last thing, I have found a deal close to my home: 2x Tekno MT410. One is brand new but already assembled, the other is an used one (this last one is sold without the shocks, and may need some repairs), 350 USD for both. Without any electronic or tyre of course. I think it is a good deal, but I have read that some people still prefer Arrma, and the MT410 needs some upgrades to be as tough as the Arrma, even if some components are better quality.
What do you think ?

$350 for 2 MT410s is a great deal. You could buy electronics for both and run both with different bodies or if you wanted to keep costs down a bit just run one and use the other one for a backup or spare parts.