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I am having issues re-installing my passenger side blend door gears. The bottom gear on the actuator was broken, so I have a replacement part as shown below. But it looks like the top mating gear is not in the right position. That gear can only be installed in 1 position, as shown. That top gear is in the position shown, with the blend door in the down position. That gear needs to rotate counter clockwise about a quarter turn to open the blend door. But you can't rotate the gear that far without it hitting the top housing. Also that would not mesh correctly then with the bottom gear. If that top gear could be shifted about 30 degrees clockwise that looks like it would fix the problem. Is it possible that shaft its connected to has slipped relative to the blend doors? Is that even possible?
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From the picture you posted, then blend door is in the closed position based on the top gear rotated fully to the right. As the blend door opens it rotates the top gear clockwise.
Does the top gear swing freely without the bottom one installed? My blend door got stuck/jammed in the closed position due to over travel. Probably when the bottom gear broke.
This is a very expensive fix as the whole dash needs to come apart to replace the whole blend door unit.

I took the plastic hvac ducting leading to the floor out of of the blend door unit. I then had to work my hand inside the unit and wiggle/push the blend door open. Very tough. This caused the top gear to turn freely and allowed me to line up the two gears.
 

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Thanks for your response! I think something is broken inside. I removed the top duct to get some view inside. With the gear as shown, the blend door is in the bottom position. The gear will only rotate counter-clockwise from this position. Its strange, because when I get a look inside (using my phone camera) it seems to be closing in the bottom position correctly, but I know the gear needs to rotate further clockwise for this work right. Therefore the bottom position must not be closed fully. Hard to explain. Here's a photo when I pushed my phone looking top down. Seems like this piece is broken. So I'm probably going to have to do what you did to get inside.
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I've got the same problem in 2011 WK2, split temp L/R, just noticed yesterday, passenger side blows hot air and the colder I set it, the hotter it gets on the passenger side.... ....so obviously my passenger side blend door is misindexed and the most likely culprit is that the gearing skipped teeth and the root cause might be the shaft for the blend door is damaged....

I'm going to look up the calibration process for the blend doors, and try that first, but if it doesn't work, then I have to start digging into the dash and fix the problem....

This has been going on since 2000 for all the manufacturers, when they started switching to these HVAC boxes that use little electric motors to position the blend doors... ....now I can see the first couple of years, them having problems and learning their lesson, but no, 20 years later its the same thing, still flimsy just strong enough plastic that doesn't last.... ....the slightest gumming up of the mechanism, and you've got the cheap flimsy plastic breaking..... ....its not like they have to make it out of steel either, you could still make the parts out of plastic, just beef it up and make them stronger, but NO, they continue to make the components "Just Strong Enough" for when it's new, which means its inadequate strength when it ages, wears and gums up some.... ...but hey at least it's in a component buried deep inside the dash that is a $1000 in labor to repair just to get inside the dash....
 

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Don't even get me started on those blend doors.

Mine broke (and rebroke) so many times I have removed the passenger side actuator completely, and now i duct tape that gear to full heat in winter and full cold in summer.

The problem as mentioned above is multifaceted. First, those inner gears, which pull straight out of the air box btw, tend to get jammed at the extremes. Then, the gear attached to the actuator breaks when trying to move the stuck gear.

Another issue is when the Jeep detects something wrong with the rotation of that actuator, it tries to calibrate again automatically, which can once again jam that inner gear. That is because calibration basically forces the gears until it feels enough resistance to assume it is at the limit.

When replacing parts, if you unplug the battery overnight the actuators will calibrate as soon as power is restored. But sometimes it jams again despite calibration, new actuator, and new gear!

The first time I replaced the passenger side it lasted for years. The next time, maybe 1 year. The final one: a month. I stopped reinstalling the glove box at this point, and out comes the duck tape.

Removing the actuator or other HVAC faults cause the fan to cycle off/on for the first few minutes of each drive so I live with that too.

On the driver side I only replaced the actuator once and it was so difficult that words can not descibe. Imagine my surprise when the replacement only lasted a month. What did I find? That inner gear jammed again to one extreme. I used a screwdriver to shove it loose and when it broke free the screwdriver slipped and snapped off one of the posts for the actuator screw.

So I jammed the actuator in place with some tinfoil and duct tape wedged against an airduct. That actuator is still wired in but I only touch the dial twice a year when I switch the other one, because it only has a few turns left before it falls out.

This is not my DD but I do have to say Im annoyed it has come to this.
 

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Chrysler used to be best in the Industry when it came to this crap, they designed the vehicles with servicing and repair in mind, and were much easier and cheaper to repair and service then other vehicles.....

The whole industry has thrown this concept out, but starting with Daimler and even worse Fiat, this idea has completely gone out the window.....

For the engine, they select plastic intakes, oil pans, valve covers... ...so instead of making a slight change in the engine block for repairability, they instead come up very expensive special tools and procedures that make changing and engine mount, 3 times longer and more difficult, i.e. very expensive and only the dealer can do it (for the most part)...
So when it comes to selecting engine mounts, I guess they just forgot how difficult and expensive they made changing the engine mount, and then select a type of engine mount that only lasts 1/3 as long as your typical engine mount....
What used to be 1/2 hour in the driveway with a floor jack and $40 worth of new engine mounts, at 200k miles, now requires paying the Dealer $800 to do every 60k miles....

Removing the Dash costs $1k in labor at the Dealer, so you'd think the Manufacturers would make sure the couple things that go under that dash that require its removal to repair, might make sure they were the least likely to fail? Nope, started with Daimler, the rash of evaporator failures because they were rushing them through production and not finishing the cleaning process properly, resulting in acids being left inside them and eventually holes forming....

The whole industry is suffering from these HVAC boxes, absolutely ridiculous after 20 years, every component is cheap plastic just built to adequate strength for when its new, they all eventually fail because the components break and jam because they are not strong enough to deal with any additional stress that would likely come with age.... ...and they don't even need to make them out something other than plastic, just change the design to be a little thicker and more sturdy shapes.... ....look at the photo above with the shaft bent in the center, right at one of the pockets, are they even needed? and do they have to be square with stress riser corners and weak spots with minimal material at square corners? after 20 years, they have learned no lessons and still put out crap like this?
 

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Discussion Starter #7
Thanks for everyone's comments and feedback, and I totally agree. For my issue, I figured the blend door was out of position, but I gave up on fixing it myself. I had cut a small access hole, but it was really hard to see what was going on inside. I took it down the street to my local mechanic. He was able to put the door back in position for me, and get it all back together for $350 (CDN). It was tricky for him too. Not sure how long it will last, but it its working for now.
 

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I did find the air blend unit, it must bolt on to the rest of the HVAC unit, for like $180..... ...but alas, that will require removing the dash to replace.....

I'm going to research it more, I have seen posts where folks have gotten just some of the small parts and didn't have to resort to purchasing the entire sub-assembly....

But usually there is a reason why the gears skip teeth and the doors get misindexed, so just resetting the gears and door index gets it working again, but only temporarily.... ....you have to fix what ever is at the root cause of why the door hung up and forced the gears to skip teeth in the first place....
 

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So I just dove into this airblend door issue on my WK2......

I have removed the glovebox and trim pieces on the passenger side to get access to and remove the motor and gear for the passenger side airblend door, the gear has the limiter block on one end snapped off (i.e. it must have over rotated to snap that part of the gear off), I've ordered a new one, the gear to the airblend door itself appears to be misindexed (out of place in clock position) and the door seems to jam up with resistance trying to move it back into "what logically appears to be the proper position/index"......

This appears to be my exact problem, that someone is demonstrating in the youtube video, except mine is on the Passenger side and not the Driver's side (keep in mind my air distribution box is still in the vehicle, the dash is still on).....

This is what I'm talking about the poor design still after decades....
They switched to a drum with ventilation openings instead of flapping doors, great probably stronger and more reliable, less likely to snap the cheap the plastic shafts from the load and stress of the long doors....
But they never put any limiters on the drum rotation, other than the flexible seals....
So I'm sure in their testing, the soft seals were just strong enough to limit the drum rotation; but what about with age and wear?

Why do the suppliers of these HVAC systems have such a slow learning curve? And why hasn't FCA insisted they fix these things?

The WK2 is approaching a decade in production/service, and no has said to the supplier, we're experiencing too many very expensive repairs on your HVAC box and it appears if you just modify the design to add a hard limiter to the airblend drums rotation it would prevent most of the failures......

I'm going to do my best to force the seal and drum past that lip it hangs up on and get the drum rotating in the proper index again. If that doesn't work, I'm going to have to pull the dash the air distribution box and heater core to fix this.... ...ugh....
 

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Dang, $1300 bucks??

I've had my problems with the passenger side actuator. Sure seems like the doors have some sort of goo that makes them really sticky after a few years. Then all hell breaks loose. ?
 

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Dealer probably charged $300 for the air distribution box and $1000 for the labor to pull the dash out to get the access to replace it and then put it all back together again.

BTW, the heater core is mounted in that air distribution box, which makes removing it even more difficult, BUT still far better than the AC Evaporator....

I tried to fix it last night, I pulled the floor vent tube off the air distribution box, that has an opening with a door, just above the drum shaped air blend door.... ....my hands are all scratched up trying to get my fingers in there, can only get enough of my finger in there to feel one corner of the seal and push it down slightly. What I feel in there, the position of gear and how it acts trying to move it back to center all support I have the same thing in the video. I tried a lot of different things last night, but nothing could move the barrel enough to force the seal past the lip far enough to break it free, so the airblend door is over traveled and stuck on full heat on the passenger side.....

Two options left before I'm forced to bite the bullet and remove the entire dash just fix this stupid little cheap plastic drum that was so poorly designed it got stuck in full heat mode....
  • Try to remove the distribution door from floor vent so I can get more of my hand in there, which is risky that I might break the parts....
  • Cut a hole in the side get access to force the drum back into position....
I can't live with this, well maybe thru the winter, but come spring and summer it has to be fixed, as it is now, I'm uncomfortably hot doing my best with the vents closed off on the passenger side and the driver side on the lowest temperature...... ...summer time my vehicle will be a sauna even with the AC on..... ....so I may be doing a dash removal this spring.....
 

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Tell you what else annoys me... This being broken really tanks the potential resale value and sellability of the vehicle.

Who is going to buy a used car without working AC/heat controls? I've got to drive it until the wheels fall off now.
 

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Tell you what else annoys me... This being broken really tanks the potential resale value and sellability of the vehicle.

Who is going to buy a used car without working AC/heat controls? I've got to drive it until the wheels fall off now.
OR
  • You could take it to an independent shop that would charge less than the Dealership
  • You could repair it yourself
  • Get an estimate from an independent shop that is much lower than the dealer, and present the estimate during sale with the fair market price marked down the cost of the repair
I agree its incredibly aggravating they allow poor designs that create this situation and it reflects very poorly on FCA as a company......
.....but its not like you've been doomed to live with this car until the wheels fall off....
 

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SUCCESS!

I was able to force the seal past the lip of the frame of the overtraveled air blend door, it now moves freely in its normal range of motion.....

The secret was removing the air distribution door for the floor vents, which the port is just above the air blend door.... ....Once the door was out, I was able to get my entire big mit in through the port, and work the seal past the lip and force the drum edge with even force and pop the drum/door right back where it should be.... ....Only took 5 minutes, compare to the hours I spent before, once I applied the pressure in the right spot....

Put it together with the new gear, got a new actuator as well, no sign anything was wrong with the old one, except the door was overtravelled and jammed, so why risk it happening again with this actuator.... ....installed it all, went to test it, the actuator won't move.... ....neither does the old one.... ....I have been driving with the actuator disconnected for the last few days, waiting for parts, maybe that has something to do with it, it calibrated itself for no actuator connected? ....I have the replacement actuator installed, before a could research some sort of calibrations procedures, after a couple of start up's and shut-downs, it started working and all is working perfectly now....

Still have to put the glove box and trim pieces back in, afterwards I might do a tip/how to in the tips section....
 

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Trick to aligning gears is carefully prying apart actuator and turning gears to correct position. Mine had an arrow on shaft and actuator box. At that point it was lined up correctly.
To calibrate I did repair with battery disconnected and it self calibrated on start up. Works great now. I did passenger side two years ago.
Here is a link for drivers side, awesome video. About 2-3 hours of pain and misery but it's done...
 

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SUCCESS!

I was able to force the seal past the lip of the frame of the overtraveled air blend door, it now moves freely in its normal range of motion.....

The secret was removing the air distribution door for the floor vents, which the port is just above the air blend door.... ....Once the door was out, I was able to get my entire big mit in through the port, and work the seal past the lip and force the drum edge with even force and pop the drum/door right back where it should be.... ....Only took 5 minutes, compare to the hours I spent before, once I applied the pressure in the right spot....

Put it together with the new gear, got a new actuator as well, no sign anything was wrong with the old one, except the door was overtravelled and jammed, so why risk it happening again with this actuator.... ....installed it all, went to test it, the actuator won't move.... ....neither does the old one.... ....I have been driving with the actuator disconnected for the last few days, waiting for parts, maybe that has something to do with it, it calibrated itself for no actuator connected? ....I have the replacement actuator installed, before a could research some sort of calibrations procedures, after a couple of start up's and shut-downs, it started working and all is working perfectly now....

Still have to put the glove box and trim pieces back in, afterwards I might do a tip/how to in the tips section....
Spent a bit of time on my passenger side tonight. Following your suggestion, I removed the floor ducting and was then able to get the air distribution door out. The rubber on my distribution door, as well as the blend door is all a melted, sticky mess??? I had to use brake cleaner to get it off my hands. I could put it all back together and probably have working heat/AC for a while, but one or more of these doors is going to stick again. Haven't looked at the drivers side yet (which clicks non-stop, so at least the gear is broken). What the hell would have made the rubber seals melt?

I hate this Jeep so very much.
 

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What the hell would have made the rubber seals melt?
Heat or Chemicals, mine weren't melted... ....you'd think the rubber they used would be well above the temperatures the seals would ever be exposed to.... ....not sure what chemical could get in the ducting, but I've seen cars that people were utterly stupid in what they think would clean with and damaged plastic and surfaces with crap like oven cleaner.....
 

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I had the blend door issue (AC working on the driver side but blowing hot as possible on the passenger side). I replaced the broken gear and also put in a new actuator. Now, when I turn on the truck it spends like ten or 15 minutes making an awful clicking sound with the AC turning on and off. After that the AC works perfectly on both sides, but it goes through that process again every time I turn the truck on.

Any ideas what the issue is? I feel like I didn't install the gear teeth properly and it's slipping around until it finds the proper alignment, but then I don't know why it would have to do it more than once. Thanks
 

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Heat or Chemicals, mine weren't melted... ....you'd think the rubber they used would be well above the temperatures the seals would ever be exposed to.... ....not sure what chemical could get in the ducting, but I've seen cars that people were utterly stupid in what they think would clean with and damaged plastic and surfaces with crap like oven cleaner.....
I've owned it since new; it isn't chemicals that have caused this. Since posting I've come across a few other guys with the same issue, so I'm putting it down to a materials failure.

No way to repair this without replacing the entire air distribution unit, so I guess I'm ripping the dash out.
 

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I had the blend door issue (AC working on the driver side but blowing hot as possible on the passenger side). I replaced the broken gear and also put in a new actuator. Now, when I turn on the truck it spends like ten or 15 minutes making an awful clicking sound with the AC turning on and off. After that the AC works perfectly on both sides, but it goes through that process again every time I turn the truck on.

Any ideas what the issue is? I feel like I didn't install the gear teeth properly and it's slipping around until it finds the proper alignment, but then I don't know why it would have to do it more than once. Thanks
On a related older thread, if your fan cycles up and down there is an error with the actuators test cycle because of broken or misaligned gear. It won't throw a code on dash, but the cycling is the computers way of showing the error. Mine did the fan cycling when one side failed, but when I properly aligned new gear with actuator by actually prying apart the actuator and turning gears to the proper alignment everything worked fine when I powered up the system and the actuator did its first test.

I have now done both sides, but there was a lot of good information on any related threads.
 
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