Air Recycle Motor “DIY” gear repair.

[Digger]

So that tick, tick, tick, under the dash has finally ticked you off enough to do something about it and when you Google it up looking for the best price, you find the instructions on how to remove the air recycle motor and re-clock the big gear.


The big gear only moves a quarter turn and re-clocking it to bypass the bad tooth is the ten minute job that it is supposed to be, but along with a broken tooth in the big gear, this motor also had two stripped teeth on a smaller gear and it’s going to take a little more than re-clocking to repair this assembly.


This is not the end of the mechanism, but it does add another twenty minutes to the job. With 3D printing available through online services, implanting new gear teeth will probably become a lost art, but for this movement you don’t need the tools of a machinist or the skills of a watch maker. Your tools are a drill bit, wirecutters, and a small file if you have one. Your materials are a paperclip, glue and as there is no stress on this gearing except at end of travel, the paperclip is optional and if you don’t have a small paperclip, a wooden toothpick will do.

The most important part is drilling the hole in the right location at the right angle. If you don’t have a drill press, wrapping the shank of your drill bit with tape to build up the size and make it easy to manipulate by hand, will get the job done almost as quickly. If you have a pin vice, don’t waste the tape.

After you have drilled your holes, glue your material into place. “Super glue sets up faster, I used JB weld because it photographs better.”


After your glue is set, cut your stud to a length just a hair bit shorter than the full gear height.


Then cut or file a taper onto the tip of your new stud. Partially reassemble and test for movement without binding.


The smoother it moves the better and for a full tooth repair this is only the beginning, but we don’t need a full tooth here so long as this is not the one spot of the gear that is stressed. (Note: Binding with, or gouging into the adjacent drive gear with your new stud will shorten the life expectancy of this repair.)

Partially assemble and insure that this section of gear does not contact the driving gear at end of travel. Notice the new location of the broken, now missing tooth of the large base gear and the location of the stud implant for end of travel reference.


The drive motor is attached to the other half of the clam shell and when you snap that back on you should be good to go, but do plug into the wireharness and test operation before reinstalling.