QuestionQUESTION: I have a driver side window that goes up and down partially and then hangs up and makes a groaniing sound. I can wiggle the window and it will travel a little and then hang up and groan. I wiggle it some more and I get it full up. Same thing for the down cycle. I think I have an idea but before I dig in wanted your professial opinion. Thanks.
ANSWER: Hi Brian,
Subaru has one of the most reliable window regulator systems on the market, so my experience with them is somewhat limited. However, from what you are telling me, it certainly sounds as though a failing motor is the most likely cause of the problem.
Please send a follow up question if I can help you with anything else.
Ben ... the power window guy
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QUESTION: Thanks for the fast reply. Okay. I thought perhaps the linkage was getting snagged but I could not see anything obvious. When you say motor going bad, why would it work at certain points of window travel? What do you think is wrong with the motor?
ANSWER: Hi Brian,
It is possible that the gears inside the head of the motor are slipping. However, it is really hard to say without actually hearing / seeing the motor work. Sorry I can't be more specific. I just don't have enough information to be completely sure.
If you have a regular mechanic that you trust, I would let him listen to it and get his opinion. That shouldn't cost you anything but a little time.
Ben ... the power window guy
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QUESTION: Thanks Ben. The sound I have more specifically is a ratcheting, skipping, grinding kind of sound. When it happens the door assembly actually vibrates. So since I am able to give the window a little persuasion and it continues to move I did not lean towards a motor. I figured if the gear was missing teeth or stripped I would not get as much window travel as I get. It almost seems like it is hanging up on something and the motor has enough torque to spin the gears. Problem is I do not see it catching anything. I do have the door apart but so I have a good perspective. What kind of details would help you better since you are not able to see it? Maybe a better question would be can a motor with a gear that is fouled still partially work like in my scenario? Mechanically I have a strong skill set but zero experience in this area. Thanks again for all your help and I look forward to your response.
AnswerHi Brian,
Let's keep talking about the motor for a bit longer. It may not be the cause of your problem, but let me give you a better understanding of what I am thinking about so you can confidently eliminate it.
The motor armature turns a worm gear, which turns a planetary gear, which turns the drive gear. A worn spot on the planetary gear produces slipping at just one spot during each planetary gear rotation. It takes 2 to 3 rotations to raise / lower the window so if the motor has a bad planetary gear you get 2 or 3 "slips" while trying to raise the window.
So, if the motor is not the problem, what else is there?
The drive gear on the motor engages the teeth on the regulator arm. If the teeth on the regulator arm are worn, the motor drive gear slips. I doubt this is your problem. Regulator teeth typically only wear out near the top of the regulator, not at several spots along the regulator arm.
What about the "support channels" that stabilize the front and back of the glass? You should be able to see two vertical "rails", one at the front of the glass and one at the back of the glass. Attached to the glass you should see "guides" that slide up and down on the vertical "rails." These "guides" and "rails" are critical to the performance of the mechanism. Anything wrong there could definitely put a load on the motor that would cause it to stall.
You should be able to see the heads of four bolts in a rectangle pattern that hold the window regulator to the door. I have seen one or more of these bolts come loose. Over time, the loose bolt wears a hole in the door sheet metal that causes the regulator to "shift" whenever power is applied to the motor.
The regulator arm that lifts and lowers the window uses a plastic guide at the end of the arm. Occasionally the guide or its stem can wear out or break causing the mechanism to operate poorly.
Hope this helps you discover what is wrong. Feel free to send another follow up if you have any other questions.
Ben ... the power window guy
