DIY: Door Lock Actuator - Internal Motor Replacement
 

What?
Replace the door-lock actuator internal motors which fail and cause the failure of the power locks. There are many thread on replacing the actuator ($100+ each) and a few on cleaning the motors to get them to work again. In my case I had one motor (driver side) that worked marginally after cleaning and another (passenger side) that was totally shot, rendering my power lock system dead on both doors. This warranted searching for a replacment motor. I highly recommend replacing any motor that needs cleaning. It's only a matter of time before that old motor dies again.

Parts Needed:
• Unlocking (?) motor: Mabuchi FC-280PC-22125 motor with 20mm shaft (not standard 9.8mm shaft). I bought from eBay member "zinky86" for $6 each shipped.

- It turns out this motor is a common size used by many manufacturers in door lock actuators specifcally. The eBay ad I bought from mentions this motor is for Lexus/Toyota actuators.

- Manufacturer Spec Sheet: http://www.mabuchi-motor.co.jp/en_US...fc_280pcsc.pdf
The specs on this sheet all match the motor from the MINI except for shaft length. You can also see this motor size has four options for RPM, torque, current. I pretty-much bought based on finding one of these with a long enough shaft which is how I ended up with the "-22125" model.

• Locking (?) motor: ***NOTE*** From my testing of the functionality of my motors, I discovered that the "20005" and "0301" motors used in this actuator have opposite polarity even though they have the same external dimensions. So in the same slot, one motor spins clockwise and the other spins counter-clockwise. In this case I lucked out and the Mabuchi FC-280PC-22125 motor I used has the same polarity as the broken "20005" motor that needed replacing. I will try to search for a matching motor so I can update this DIY.

Steps:
• Remove Door Panel and Door Lock Actuator: https://www.northamericanmotoring.co...roblems-6.html See other pages in that thread for more removal instructions.

• Disassemble Door Lock Actuator: http://www.instructables.com/id/Repa...or-L/?ALLSTEPS

Some notes from my disassembly: I broke every one of the white clips that hold the case together. I gave up on the second one and just broke them all on purpose. Upon reassembly I found the four torx screw hold the case together well enough. I did not have to remove the black gear shown in step 8 of the instructables.com link.

• Here's a shot of my motor set-up. The motor I labelled "0301" is made by Mabuchi and was still functional on both my left and right actuators when I applied 9v/12v. The motor I labelled "20005" is made by Johnson (Controls?) and was broken on BOTH my units, just like the person who did the instructables.com article. I'd bet this motor is the issue on most failed actuators out there. Disregard all red arrows I wrote with a Sharpie on my motors and casing. This was from testing rotation direction as I mentioned above.
Attachment 157592

• The first step beyond the instructables.com guide is to salvage the brass worm gear from the original shaft. I set up a vice grips to support the worm gear while not gripping the shaft itself.

Attachment 157593

• This worm gear is pressed-on tightly so I used my heat gun, a large screwdriver and a hammer to tap the worm gear off. Since this motor is junk, don't worry about hammering on the motor body. It's not too hard to tap this off but you certainly won't be able to pull it off by hand.

Attachment 157594

Attachment 157595

• We have now seperated the worm gear. I suggest degreasing the worm gear before applying heat as you will burn the residual grease.

Attachment 157596

• Now this could be a pretty straighforward motor swap, but I could not find a replacement motor with a roughly 30mm (1.181") shaft like the stock motor. The longest I could find is 20mm (.787"). So, we will need to butt two segments of shaft together, with the butt centered in the middle of the worm gear. Butting in the middle provides the straightest shaft and stongest joint.

Attachment 157597

• To accomplish this we first need to trim the NEW motor's exposed shaft to .525". I used a Dremel and cut-off disc for all my cutting.

Attachment 157598

• Next we need to salvage part of the shaft from the junk motor. Cut this piece to AT LEAST .570". One of our last steps will be to do final trimming of the completed shaft assembly, so don't worry about making it a little longer than .570".

Attachment 157599

• Now a summary of our pieces. .525" of our new motor, >.570" of our slavaged motor shaft and the general location of the worm gear.

Attachment 157600

• Now we need to tap the worm gear onto the new motor shaft. First, I suggest using expoy or even red Loctite on the shaft to help secure the worm gear. I also suggest scuffing up the motor shaft to help the expoy adhere. Always support the far end of the motor shaft when tapping the gear on. In this case I put it on my vice's anvil.

Attachment 157601

• To center the worm gear on the butt joint, tap the gear on until you get a .150" gap between the worm gear and motor housing. After I tapped it on, I used a needle nose vice grip to prevent the worm gear from moving further down on the shaft when I tap on the salvaged piece of shaft. In this case the width of my needle nose was conincidentally .150".

Attachment 157602

• Starting to tap on the extension with a hammer. The grey goo is the JB Weld epoxy I used. You can feel and hear when the extension is fully seated and in-contact with the motor shaft.

Attachment 157603

• Clean up the epoxy and measure the TOTAL shaft length. In this case 2.659". The end of the shaft need to be trimmed to achieve no more than 2.50" total shaft length.

Attachment 157604

• Trim carefully. I think I ended up at about 2.495" which is just fine. Going over 2.50" will cause friction in the slot the motor clips into (this spec only applys to the unlocking "20005" motor). The "0301" locking motor has a different slot it clips into and is not as critical to total length.
Attachment 157605

Attachment 157606

• New motor in place! You can see at each end of this motor shaft are two little metal plate which dictate having a precise overall length. The other motor has "open" ends.

Attachment 157607

Summary:
After replacing both "20005" motors in my car (left and right door), my central/power lock system is now 100% functional! $12 well spent :)

Overall the project is not very hard. Getting the actuator out of the door is a little tricky, but after the first one it becomes easy and you learn where things go and how it's put together. Disassembling the actuator itself is pretty easy and as I mentioned above, all my white clips broke. I had little 1" square pieces of plastic milk jug ready to go but could not slip a single one in a clip.

I suggest using new grease in the new actuator. Just wipe off the original white grease and wipe on new stuff.

When installing the interior door pull cable, I suggest using a pea-size glob of RTV silicone and squishing it in onto the blue plastic end of the cable after you snap it into place. This is the end of the cable that commonly comes loose and making the interior pull inoperative. The silicone gives just enough glue effect that it will probably never come loose again, but its also soft enough to remove the cable without issue.

I think the trickiest part of the project is mating the "L" shaped latch and actutor (motor housing) together. There is a few levers that need to be in the right place for it to snap together. I have noted a few below. And don't be afraid to flip the levers around a bunch to see what-moves-what. No parts will go flying.

Attachment 157608

First, the gear I labelled "No Need To Remove" can stay put. You do need to take off the little white connector seen in the instructables.com article, but after that's off you can flip the lever to one position and have just enought room to get the torx screw out that sits behind it.

A:
The little gold lever is spring loaded and its natural position is to move towards the middle of the latch. You need to hold the lever against its spring pressure and have the black plastic lever hold it back.

B:
The lower metal lever had a "U" shaped cutout. There is a black plstic pin that needs to rest in the middle of the "U".

C:
The metal lever needs to stay inboard of the black plastic pin.

D:
This piece is on the driver's side actuator only. There is a little notch on the white piece and mark on the black piece that should line up. This white piece rotates about 180 degrees. When lined up on the mark, it should be able to rotate about 90 clockwise or 90 counter clockwise. This correlates to your key slot in which you can rotate 90 clockwise to lock your door or 90 counter-clockwise to unlock it.

Thanks for this! My passenger door lock went out several months ago and I finally got around to fixing it. I followed your guide and this instructable. I didn't replace my non functioning motor, but opened it up and cleaned it and all is well again.

That's pretty cool, very nice write up.

Can't believe nobody commented on it in the almost 3 years it's been there until today.

I am surprised as well. This is definitely a very nice write up and great resource as it should be very useful for the gen 1 MINI owners with actuator issues.

I know. Somehow it slipped past everybody. For what it's worth, this was a pretty easy repair. I think in most cases, those little motors just get fouled up inside, and can be opened up, cleaned, and reassembled with a little patience. The instructables guide I linked to in my last post describes the process, and it becomes a free repair.

I broke most of the brittle white plastic clip pieces off on mine. At first by accident, then almost out of spite. They didn't seem necessary to hold it back together.

This was a great fix and a solution to the "fonzie method" , well done. :)

Question about motors
 

Good afternoon, you're the only one on the internet that has the solution to this problem, I congratulate you for such a good guide.

I have a Discovery 2 and the passenger door do not open or close, I guess that it is a bad motor and the tail door has the same problem.

I wonder which motor make and model did you used for the locking motor? that have understood that the motor to UNLOCK is the FC-280PC-22125 model. But to LOCK is the same motor model and spec?

Once more congratulations for such explicit guide and sorry for my English, I'm from Venezuela.

Congrats for the tutorial on the fix. It is very useful.... the only problem that I am encountering is that when I try to open the door it locks and when I try to unlock it locks o.O ... any suggestions please, I have bought the Mabuchi FC-280PC-22125 motor and replaced the same faulty motor as described on the tutorial

I have replace the unlock motor as per the guide but now have a problem.

When unlocking the door actually locks and vice versa! Any ideas where I went wrong?

Did you find a fix?

were you able to fix your problem? Is this actuator same for Land Rover Discovery 2?

If not then you must call the dealer or locksmith , they can replace the actuator with the new one. Also, they will describe how to prevent those problems to get in with your locks.

Yeah i have done as you said , have called the locksmith and the replacement has been done by them. It's been at very fair cost and they offer warranty for 3 months also.

You have done well but in such cases you must take help from locksmith and then they will resolve the issue well..

You have done well but in such cases you must take help from locksmith and then they will resolve the issue well..

Take out the motor and cleaning it well is also a good way to check the problem but if this doesn't work then find nearby locksmith and ask them to replace the actuator. Repair can cost much as compared to replacement and there is probability of getting it serviced again so replacement is necesaary.

I had hired locksmith dallas tx for that work , they replaced the actuator and solenoid both. Now it works fine with no issues.

Has anyone solved the issue of the reverse locking?

John i think you should talk to locksmith brooklyn, may be they can help you with it. My all lock issues has been resolved by them.

This is caused by the motor being the wrong polarity. Instead of it rotating right (for the lock) its rotating left. Simply reverse the rear of the motor 180 degrees, you may have to notch the casing to allow it to reseat back in but it does work.

I just resolved my door locks the same way. You can also use the 20mm motors without the need for adding the extra spindle length. The rest of the spindle is for support but the motors are such a good fit in the housing it does not impact the operation of the doors without the extra length. Simply order the Mabuchi FC-280PC-22125 motor with 20mm shaft as stated, rotate the rear 180 degrees if you receive the wrong polatiry motors. That means you can use these for all the motors in the locks.

I realize this is an old thread but I did have the same issue so I've added it in the hope I can save someone a lot of time scratching their head.

Motor reverse
 

Thank you Josseh for this clarification!!!
I just replaced both the motors and I was driving mad after seeing that the lock motor run in reverse!!
This evening I re-open the actuator, rotate the motor head and see if it finally works.

Hello everybody,
as I wrote yesterday I re-opened the driver side's door lock actuator wich was working bad after I replaced both the motors.
In particular the issue was with the LOCKING motor wich was working inversely (unlocking the lock instead of locking it).

I easily turned the plastic motor's head of 180° (as Josseh explained), reassembled the actuator....AND NOW IT WORKS PERFECTLY!!

At the moment also the passenger door handle's cable is detached from its door lock so, since I'll have to disassemble the door's panel, I'll take advantage of it to change the motors as well.

Thank you again to AutoCoarsen and Josseh!

I'm really pleased to hear my post helped someone else. It makes it worthwhile registering just to post it. Good luck with those other little fixes.

Thank you guys! it was very helpful and clear, and very smart trick for change polarity

It's also helpful for R56, there is a little difference between only with one motor in. So there is what i have done

https://cimg7.ibsrv.net/gimg/www.nor...ef841c2d13.jpg
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