help -- 108 4.5 park won't hold

[kpb]

came out of a shop this pm (NAPA) and plunked my rather sturdy butt into the seat of my daily driver 108. Parked on a short but steep slope -- SURPRISE, I'm rolling backwards and notice a ka-chunk, ka-chunk, ka-chunk sound (and feel). DAMMIT.

Is there some type of parking pawl in the V-8 tranny that snapped? Car starts and runs fine, just gotta set the parking brake to hold it since "Park" really is no longer. I've been leaking serious AT fluid since I got it (12/03) but stay on top of the level. Any connection? And, If I dig into the tranny to fix the "park" issue, any suggestions on seals, gaskets, etc., to change in the hopes of minimizing my AT leak(s)?

As always, my gracious appreciation to each and all is extended...

[luvthe111]

My Cabriolet used to do it as well, and for a few years I just used the parking brake. I finally got around to taking it to a tranny shop. They dropped the pan, adjusted something inside, closed it up and I paid them $80. I guess it happens frequently that they knew what was wrong right away. Bonus was that I need to reseal the pan anyway.

Perry

[Mark DiSilvestro]

I'd check the shift linkage bushings and adjustment first, otherwise, the problem is inside the transmission.

Happy Motoring, Mark

[kpb]

Thank guys. I'm gonna dig out my parts picture manual and try to discern something useful therefrom.

My major concern is, if something snapped, will I risk inordinate damage by driving it around with some piece bouncing around inside the tranny?

[leenart]

Probably your shift linkage is out of adjustment. That kachunk sound is the prowl skipping, thats a good sound as it means everything is working you just need to bring them together. Probably need to replace one or more of the plastic bushings. You may need to adjust the linkage, but the best thing is replace the bushings. If they fail, your linkage drops out and then you get to shift your car by placing your hand under the transmission and manually shift it. Remember to put the parking brake on before attempting this one
I carry an extra bushing just in case mine wears out and strands me.

[Tomguy]

The prawl or pawl or whatever the hell it is... I hear these can be bent, or can get out of adjustment.

It's more likely to happen if you have a column shift than a console shift, but your linkage could be out of adjustment too.

Mine is bent or out of adjustment, I just keep my parking brake set all the time and I have no problems. I've yet to have it roll on me in the time since I've "resurrected" it, but before that, I sat on the hood once (about 8 years ago) and it started to roll down the driveway!

It won't damage your tranny, nothing broke. It was just the sound of the lock skipping. Use your parking brake!

[kpb]

Thanx for input y'all. Looks like it is the bushing so I've got one (actually 2 ) ordered.

[kpb]

For future searches on this point -- my problem was indeed a 98 cent bushing. Unfortunately, the one I ordered appeared and is the wrong piece. In the meantime I've rigged up my own special bushing from PVC and plastic hose. IT WORKS.

Lesson: Do not assume it is catastrophic tranny damage if one day you begin to roll down the road in Park

[Mark DiSilvestro]

As long as you catch it before there's catastrophic body damage!

Happy Motoring, Mark

[kpb]

Mark -- I heard that brother, if there had been somebody parked behind me in the alley...OUCH.

[psfred]

Dude, there are only 2 types of linkage bushings on a Benz since 1960 or so -- the big one that looks like it won't fit made of Viton (it fits, but you have to press it in) and a smaller one of harder plastic used since 1997 or so.

Peter

[kpb]

psfred -- dude backatcha! wuthehell is Viton? Is it white plastic about three sizes too small to go over the lever and too small to fill the hole for the bushing

Your expert advie is needed...

[psfred]

Yup, you got the new style, or one of the plastic bushings for the column mounted shift lever.

Viton is a very stiff but flexible translucent rubber like material, often found in plastic tubing (it's not PVC).

The correct bushing just fits on the rod and looks somewhat too big to go into the hole in the tranny lever, but does with some help with a vise and a socket.

Take the tranny lever off, it's MUCH easier that way...

Peter

[kpb]

Thanx peter. Your description of the Viton bushing coincides with what is in my hand. Stiff but slightly flexible translucent item. Perhaps if I soak it in hot water first it will ease installation and also assist it into place with WD40 or PB Blaster.

Thanx again.