Cat MM55SR excavator

[WrenchDW]

mm55sr controller retrofit kit, help!!!



glad i finally found other people with the same problem, can you email me with a price and availability to the U.S. thanks kevin.

I am looking fro this same option. Can I get some information on it? Thank You.

 

[Graham Hamilton]

I've put all my information re Mitsubishi MM30/40/50 series machines on my website which has electrical details, fault codes, parts manual, engine manuals etc. It's not complete but always interested to add stuff to it.

Hope you find what you need

https://www.woodandtrees.co.uk/

 

[WrenchDW]

No parts needed so far, joysticks stopped working but soldered a new ground on computer and all is well.

Do you have any pictures of where and how you soldered the ground? It would be much obliged.

 

[Aidan166/72791]

Hi graham could you please send me the service and parts manual.
[email protected]
Cheers Aidan

Hi Pete, I'd be very interested to know how you get on with fixing this. I have a parts manuals for the MM50SR if you are interested. Your valve part seems to be part number PA4342. Graham

 

[Graham Hamilton]

Hi Aidan,

I've sent a reply to your email with the details. If anyone else needs them they can be found on my website https://www.woodandtrees.co.uk/

cheers

 

[jim hardy]

Switched it all over to the cable controls that are used on a masy Ferguson tractor. Got rid of all the electronics works great!

 

[Graham Hamilton]

Switched it all over to the cable controls that are used on a masy Ferguson tractor. Got rid of all the electronics works great!
View attachment 302069

Great photo. Have got any more, particularly of the joystick arrangement. I'm always interested to see what to do if the electronics fails.

 

[jim hardy]

View attachment 302652

 

[jim hardy]

 

[jim hardy]

Removed all electronic and wireing, just the basic stuff

 

[maximumtechnology]

I FINALLY (after about 5 years) have a ENGLISH service MANUAL and parts book. I also had a Japanese friend translate some of the marking on the machine (control buttons on the LCD AND the fuse panel).

If anyone is interested in purchasing (I spent countless hours and lots of money having this translated) you can email [email protected]. Email me for a phone number as well if you like and we can chat. I would also be willing to trade for some other mm55sr knowledge OR some other help with it, or parts.

Hello I would like to get my hands on the service manual. Are you able to help? Mitsubishi mm55sr. Thank you in advance if you are able to.

 

[Scott Whitehead]

Hi - I have tried to reach out to the emails on this thread with no luck. Did anyone ever get the ENGLISH MM55SR manual and parts book from Aksobe? If you have it, I would love to get a copy along with anything other documentation related specifically to the MM55SR. Happy to pay Aksobe for it but reached out via email and no response.

 

[Graham Hamilton]

Hi - I have tried to reach out to the emails on this thread with no luck. Did anyone ever get the ENGLISH MM55SR manual and parts book from Aksobe? If you have it, I would love to get a copy along with anything other documentation related specifically to the MM55SR. Happy to pay Aksobe for it but reached out via email and no response.

Scott, have a look at my website and open the Dropbox links under the MM30 etc tabs. This should cover most of what you are looking for. cheers G

Life in the Woods

www.woodandtrees.co.uk

 

[naved]

⚠️ WARNING: Avoid IMD – $4000 Controller Failure, No Support, and Now I’m Building an Open-Source Replacement​

Hi all,

I want to share my experience with IMD (IMDynamics) and why I strongly advise you do not buy their MM-R controller system, especially for excavator control retrofits like the Mitsubishi MM55SR.

---

Why I Went with IMD​

I have a background in automation and system integration. When my excavator needed a modern proportional joystick controller, I thought:

“Why reinvent the wheel? IMD already offers a product that looks like it should do the job.”

So I went ahead and ordered their MM-R system — a decision I now regret.

---

❌ What Happened​

After spending over $4000 NZD, I installed the system — and ran straight into major issues:

• Proportional joystick response is sluggish and non-linear
• Solenoids hammer and buzz violently — no matter the settings
• The system lacks the finesse and feel needed for accurate digging

I followed every instruction and even ran their joystick calibration tool — no change.

Trying to solve the issue, I went above and beyond:

• Sent them detailed voltage readings
• Shared joystick outputs in neutral and active states
• Provided photos of settings, wiring, and system behavior

Tony from IMD even admitted that some customers had experienced the same issues — but since then, they’ve stopped replying.
It’s been over two weeks with zero communication, even though they know I'm based overseas and likely can't do much about it.

---

What I’m Doing Now​

Since I’m not getting any support, I’ve decided to build my own open-source replacement using modern, accessible components.

I've already ordered the parts to build:

• A Teensy 4.1-based PWM controller
• Logic-level MOSFET drivers for the 12 V solenoids
• A touchscreen interface for settings and calibration
• Full safety and fine-tune logic: deadzones, curves, neutral switch, etc.

I’ll be releasing everything publicly: parts list, wiring diagram, source code, configuration tool — all for free.

The entire build will cost $400–$500 NZD total, and will be better-performing than IMD’s system with actual support.

---

Bottom Line​

If you're considering buying from IMD — don’t.
They may look like a professional outfit, but when things go wrong, you’re on your own — especially if you’re not local.

I made the mistake of trusting them instead of building my own solution. Now I’m fixing that, and I’ll be sharing every step of the way to make sure no one else gets caught the same way.

 

[madkeen]

Thanks Naved we were just about to buy from them. We are also in NZ after reading this we won't be. If you can post what you do with your MM55 we have one as well we would like to sort .