Trouble Shifting Out of Park


#1

2007 Chevrolet Impala 1LT
3.5L Flex Fuel Engine
Auto Transmission with shift lever on the steering column
29,980 miles

Bought new Nov 2006 so is now four and a half years old
The drive train is still under warranty (6 years or 60,000 miles).
All recommended service per the manufacturers manual has been done. Book calls for first transmission service at 50,000 miles

NOTE: Previously at 19,600 miles the transmission cooler line fittings were replaced due to a small leak. Currently no evidence of a leak; no fluid on garage floor and the transmission fluid level on the stick shows right on the mark. Fluid still clean pale red and has no odor.

Majority of my driving is short hops with multiple stops, so the car gets heavy use shifted into and out of park gear. I do use the “parking brake” applying it after shifted into park and released before shifting out of park. I always have my foot on the brake pedal when shifting out of park.

PROBLEM: Having trouble shifting out of park on a cold engine or if the car has been sitting for an hour or more since turned off and put into park gear. Oddly enough, if I’m running a series of errands where the car has been in park for only 5 to 30 minutes, there is no problem shifting out of park gear. But if the car sits long enough for the engine to cool then it becomes hard to shift. The longer the time it sits in park the harder it is to shift out of park when the car is started.

In retrospect, I began having slight difficulty a couple of weeks ago but the problem has become truly noticeable the past two days.

Anything in particular more I need to think of to tell the shop when I take the car in?

Per OK4450’s past suggestion, I’ll have this info printed out to give a copy to the service manager and a copy left on the seat for the mechanic to see.

Any help is appreciated! Thank you.


Marnet
…still reading, still learning!


#2

I will commend you on a very thorough account of the car and your issue. However, I will still have to ask for some info. Is it possible to describe what the shifter feels like when it doesn’t shift easily? Does it just feel really “heavy” and hard to move, but will move? Or does it literally just feel stuck? If it just feels stuck, what does it feel like when you finally get it to go?

My first guess would be that you’re having a problem with the shift interlock mechanism. Its a safety device that blocks you from shifting from park unless the brake is depressed. The device itself can get sticky, and it would not be unusual for it to mostly be reluctant to move when the car is cold. But you can also have a problem with the brake light switch. Its that switch that has to “tell” the interlock that the brake is on & its ok to get out of the way.

If its just really heavy/hard to move but it does move then the first thing I would inspect would just be the shift linkage at the transmission.


#3

Thank you for the compliment.

The shift lever is truly stuck and requires considerable force to move. With it being a shift lever on the steering column I have to slightly pull the lever toward me and downwards to the right to shift out of park. I’m able to pull the lever toward me but it is very difficult to move downward to the right. I have to move the lever away from me back into the original position it is in when in park and pull toward me again and back several times before it will go downwards and right into another gear.

If I’m in reverse and then shifting into drive I have to make the same exact motion but have no trouble when shifting out of reverse. Nor is there any problems with shifting from drive into lower gears or from moving the shift lever to the left to go from drive to reverse or into park. It is only when shifting out of park that is a problem.

Part of what baffles me is why it becomes more and more stuck and difficult to shift out of park the longer the car has been in park, such as overnight, as opposed to shifting out of park normally if I’ve had it in park only briefly such as when filling up the gas tank, running into the store for 10 minutes, etc.

I will reiterate that I ALWAYS have my foot firmly on the brake when shifting out of park.


#4

It certainly does sound to me like the shift interlock. The fact that it will mostly happen after sitting for a long time makes perfect sense if the device is sticky. I don’t know the specifics, but its probably something like a little lever that blocks the shifter. The lever is probably moved out of the way by a little solenoid. If it is just sticking from contamination, old grease, etc. then when its been sitting a long time is when it will get stickiest. Once its gotten itself moving its not stuck anymore. The same thing used to happen to the Tin Man.

I know that you mentioned always putting your brake on. But if the brake light switch has a problem or if the locking mechanism is sticky this isn’t relevant (except of course that without pressing the brake you’ll never get it moving).


#5

Well, I can certainly test whether or not I can shift out of park without my foot on the brake. I’ll have to park the car on the driveway for a few hours and see what happens when I try shifting out of park without my foot on the brake. I certainly won’t try it with the car in the garage! LOL

Thank you so much for the feedback.


#6

Well, without your foot on the brake it won’t matter how long the car sits. If you put it in park and try to move it back out without your foot on the brake it won’t come out of park no matter how long it has or hasn’t been sitting. You could try moving it from park without your foot on the brake just to see if it feels the same as when it is having the problem.


#7

One thing you can do for a test is to back in a parking space at a business with glass behind you so you can see your brake lights. Then go through the scenario where you can possibly duplicate the problem, when this happens you’ll be able to see if your brake lights are on or not.


#8

Ah, thank you Cigaroller. You had already explained how that worked but I was having brain freeze and didn’t make the connection. I appreciate the reminder explanation!

And thank you Mr. Peters for the suggestion about how to check and make sure my brake lights are working!


#9

If it is the shift interlock, is that something which is considered part of the drive train and therefore apt to be covered under warranty?


#10

This sounds like a defect, certainly not a wear problem, so yes, it should be covered under powertrain warranty,
I didn’t download it but maybe this PDF will off some insight. http://www.pdfoo.com/chevrolet/177-8646-pdf.html

Otherwise, this model experienced in 1998 the same problem, and it was fixed.


#11

UPDATE: Meant to post this sooner and forgot until now. Anyway…

Murphy’s Law being what it is, of course, the shift wouldn’t act one bit sticky for the mechanic even after they let it sit for several hours which usually produces the problem. Rather than tear into things, the shift cable was lubricated, I was given a printout about torque lock and asked to drive the car and see if the lubrication solves the problem. Given that this was the Friday at the beginning of the Memorial Day weekend, I didn’t object to that approach.

I will say that the shift lever is sticking less since the shift cable lubrication although still doing so a little sometimes. So I’m trying to pay more attention to how firmly I have my foot on the brake before applying the parking brake and shifting into park. Also, truthfully, I’ve been doing one thing incorrectly to avoid torque lock according to the car manual instructions; I habitually release the parking brake before shifting out of park and the instructions say I should shift first and then release the brake. So trying to retrain an intrenched habit and see if that further helps.

While there I did ask about their procedure for servicing the transmission. They only flush without dropping the pan and changing the filter, claiming that all that is taken care of when they “back flush” all for a price of $168. I asked about having the pan dropped and the filter changed and they said that would constitute a “double service” and would charge accordingly.

So I’m going to check with some local independent transmission shops and with the independent mechanic I often go to and see how they do the service and for what pricing. Then sometime in the next few thousand miles at most I’ll get the tranny serviced to keep it happy and healthy.

Thanks again for all the help!


#12

Sidebar: I was given specs on the condition of the brakes and tires when the tires were rotated. Both are still in good condition. But one thing puzzles me. The rear brakes have more wear on them than the front brakes. Since this is a front wheel drive car I thought the front brakes would wear faster?