The thing that goes braaaappp!

     When I drive, I drive a 1996 Jeep Grand Cherokee. Only has 120,000 miles on it; just getting broken in, right? Well, except for the transmission, the air conditioning, the brakes, the air conditioning...

     And the thing that goes braaaappp. A wonderful noise, that. Braaaappp! Metallic, bronx-cheer, always the same duration.

     It's gone braaaappp for a while now, oh, a year or two at least. I've known where it was, and had a good idea what it was. When I lock or unlock the doors, braaaappp. Thanks to "advanced features" (see "feeping creaturism"), even if you don't lock the doors, when you pass n miles per hour, the car automagically locks the doors -- and goes braaaappp to let you know it's done the job.

    The braaaappp comes from the rear hatch; I've long suspected it's the lock/unlock actuator gone woogly. It really hasn't bothered me. Startles the occasional passenger, though, as we're pulling away from someplace, accelerating, moving into traffic, and braaaappp!

     But it's reassuring (at least to me). When I lock the thing using the remote, I get a bonus -- not only a toot from the horn, but that reassuring braaaappp from the back.

     But finally I decided it was time.  Time to dig out the thing that goes braaaappp, examine it, and probably visit a Jeep dealer and see how much they want for a new one.

    I hadn't been in a hurry to do this for a number of reasons. First, there's the money. I figured things that go braaaappp aren't cheap, even if Jeep still carries them for 1996 vintage vehicles. Second, I'm not sure how much of an ordeal it will be to get to the bloody thing. Will I have to take off the rear bumper to get to it? Dismount the entire rear hatch? Those of you familiar with what passes for "automotive design" are nodding with rueful familiarity -- what was the car where you had to pull the motor off the mounts to change the oil filter and the spark plugs? If you didn't know, to replace the front hood latch on the 1996 Jeep Grand Cherokee, you have to partially dismember the front grill and front bumper. If it weren't for the plastic, it would be quicker and easier to do that job with a saws-all and a welding rig... And that's with the service manual -- which I have. But I digress... Last on my list of reasons is that I figure the damn thing is working, so why harass it? When it stops going braaaappp, then we replace it, right? Until then, let noisily farting dawgs lie.

     Wrong, wrong, wrong, wrong, wrong! The only good thing that's come out of this deal so far is that it's taught me that I live, drive, and park in relatively crime-free areas.

     So why is that?

     Got the shop manual out of the garage, and dug into it to find the proper chapter and verse. Chapter 23, verses 40 through 43. Fig. 66 is particularly enlightening. Shock! Surprise! No bizarre tools required to remove the thing! Someone must have lost their job over that, certainly... Just remove about a dozen screws (three different sizes, naturally), and pull hard to dislodge some one-way fasteners (didn't need those anyway, that's what the screws are for, right?). Oh, that's Fig. 62, lower trim panel removal. That exposes the power lock actuator. Or at least gets you into the vicinity -- the power lock actuator is hidden behind a piece of sheet metal. But that's where it is.

     The hip bone is connected to the thigh bone... Well, in the Jeep, the power lock actuator is connected via the lock rod to the handle assembly. The power lock actuator (also known as the thing that goes braaaappp) locks and unlocks the handle assembly, and the lift gate (as Jeep calls the rear hatch) via the lock rod.

     So I remove n screws and rip the lower trim panel out.

     And I don't know whether to laugh or to cry...

     Set the WayBack machine for a few years ago... I'm driving home from work. The traffic in front of me on the freeway comes to a halt. Being a physics major many many moons ago, I understand Newtonian conservation laws and the transfer of momentum, so I stop, not wanting to transfer any of my momentum to the vehicle in front of me. No big deal, plenty of room.

     The young lady behind me evidently wasn't a physics major. She didn't quite stop in time, and demonstrated that it is indeed difficult for two bodies to occupy the same space-time coordinates, transferring momentum from her vehicle to mine.

     Simply put, she rear-ended me. The good news was we were both uninjured, and insured. Her insurance company paid to get the Jeep fixed. (Aside to the aside -- my first concern was to make sure she wasn't injured, and we were safe. Her airbag didn't deploy, but my bumper hitch did a nasty job on the radiator of her shimy new Jetta. Other than being rattled, she seemed to be okay. Until I gave her my business card and she looked at it -- and blurted out -- "Oh fuck! I hit a lawyer!")

     That's when I think it probably happened, when the Jeep was repaired...

     Because when I popped the trim panel off and looked at the aforementioned lock rod, what do I see, but a lock rod dangling in mid-air, attached at one end to the power lock actuator, and most definitely not attached to the handle assembly!

     I've been unable to (automagically) lock the back of this damn vehicle for at least the last two years! But thanks to that braaaappp, I've felt safe and secure, knowing that Detroit's finest engineering minds were reassuring me (and anyone else nearby with normal hearing) that the electric lock was doing its thing.

     Wrong.

     (Break for dinner -- bbq baby back ribs, macaroni salad, mixed olives, Rheinhessen 2002 Auslese. The dawgs guarded the bbq while the ribs cooked, and got some of the bones as payment for their furry vigilance.)

     Aside -- I think this is the same hypothesis the TSA operates under -- if they're annoying enough, like the thing that goes braaaappp, they must be doing a good job, no? (No!)

     Okay, back to the scientific method -- we've formed a hypothesis, now let's experiment, observe, and see if the results of the experiment support the hypothesis or require that the hypothesis be changed. Observe the power lock actuator while pushing buttons on my remote. Braaaappp. Yup, the hypothesis is supported -- it's the power lock actuator, the power lock actuator that's actuating not one damn thing and hasn't for years, that's going braaaappp.

Autopsy

     Removed the offending device. Plastic with a slidy thingy, and the aforementioned nonfunctional already disconnected lock rod. The slidy thingy slides back and forth way too easily, and none too smoothly. Plastic case doesn't look like it's been made for disassembly, but when has that slowed me down? Not in the last 45 years at least! A bit of prying with the Swiss Army Knife...

(insert pic here?)

     Cheezy design -- big surprise, no? Motor with plastic gear and what looks like a clutch assembly, the gear on the motor shaft meshing with gear teath on the slidy thingy. Guess what -- the teeth on the motor shaft gear are chewed to shit. In (presumptive) normal operation, the motor turns the motor gear which meshes with the gear teeth on the slidy thingy, translating rotary motion to linear motion until the slidy thingy reaches the end of its damn travel and the clutch mechanism on the motor shaft slips. But in non-normal operation, when end-of-travel is reached, gears chew against gears, producing that wonderful braaaappp as gear teeth are chewed up.

     Interim conclusion: there's nothing here for me to fix. Replace the trim panel and the screws.

     Close the rear hatch and lock it with the damn key. Press the lock button on the remote. The vehicle is locked for the first time in years. Quietly, too! Sniff, kind of miss that braaaappp already!

     Perusal on the World Wide Wait (WWW) popped up no instances of the aforementioned power lock actuator, although Google did present me with a web page which said that wonderful braaaappp noise was undoubtedly a power lock actuator that wanted replacing.

    Remaing to do:  (1) clean up the dishes, (2) decide if I want to take pictures of the stripped gears or not, (3) visit a Jeep dealer and find out how much they want for a new one, assuming they can get it.  What's my monetary threshold of pain on this one? Not sure. I know it's locked now.

     A successful endeavour? Not sure. I know what goes braaaappp.  I know why it goes braaaappp.  It doesn't go braaaappp anymore. Partially, it's like a scab that's finally gone -- nothing to pick at anymore. Maybe I'll replace it, maybe I won't. We'll see.

Update 2005 August 13

    Talked to my friend and colleague Marc -- we found the thing on some websites, learned that the same unit was used from 1993 - 1998, and once I figured out how to reduce the search space, lo and behold!  I found one on eBay! (The secret to good searches, as I should know from using Lexis/Nexis for a long damn time, is restricting the search space just enough.) The one on eBay didn't have a "buy it now" option or I would have. Gave it my best shot, figuring it was a pig in a far-away poke. N days later, can you say sniped? Lost it in the last five seconds. Oh well, how many times have I done that to other folks? He who lives by the snipe dies by the snipe.

    Ended up at the Dodge/Jeep dealer parts counter, but after talking to the guy I take the Jeep to. He says, "I call in part for you! Save you money!" He did; I did. As I groused with the parts guy behind the counter about cheezy design, plastic gears and all, he told me that the redesigned part uses much better gears.

    Looked at new things -- they want $44k for a new Jeep? "With DVD player!" touts the saleshark. But I don't want a damn dvd player! Looked at the Dodge Magnum and 300. Took a while, but I figured out what bugged me about them. Weird, throwback design... Aha! A muscle car for the Viagra set! Don't need that. Not yet, anyway.

    Took a few minutes to install the new power lock actuator. In searching on eBay I found a set of speakers (weird-ass Infinity sound system) and got that so I could replace the speakers in the rear passenger doors that make ugly noises.  That took a few minutes. Also got a replacement passenger side mirror to replace the one I altered slightly in backing in a little too closely to a brick pillar; that one I'll do later today or maybe tomorrow.

Namaste-

Bob