Transmission clunks in Park

I've noticed in the last week or so that whenever I put the car in Park, that if the car rolls forward toward the stop, that it "clunks" as it gets to the stop. Whenever I park on a slope, I use the parking brake, but not on level (or relatively level) ground. For instance, at work, I rent a space and the car sometimes will roll just slightly when I park...othertimes, it won't. If it does, it will "clunk" as it touches the stop. I just had the oil changed the other day and the transmission fluid was checked then and I was told that it was full, plus it was bright pink and no smells to it at all.

I think, to be safe, I'm going to have to start using the parking brake whenever I park, regardless of the slope...or lack thereof.

But is this an indication that my transmission is starting to go bad?

It's possible that you have a bad motor mount, or even internal damage to the paul lever, but I would always use the E-brake when parked on a slope, rather than relying on the internal park lever (paul) inside the trans. Follow the procedure below.

1) Stop vehicle;
2) Firmly set Parking Brake;
3) Put transmission in Neutral;
4) Let off foot brakes (slowly, to make sure Parking Brake is holding); then
5) Put transmission into park.

If you follow this procedure, there is no strain on the transmission whatsoever.

I was thinking of the parking pawl, too, but I've never seen one go bad. I always use my Parking Brake on a slope, but I'll start using it always now, just to be sure my car stays where I park it.

I've had a motor mount go bad about 3 years ago...my mechanic found it while working on something else. Not a stretch to think another one has gone bad. How many are there on this car?

I have broken several "Anchor" mounts within a year. Did your mechanic use a genuine GM mount, or Anchor Brand? You should inspect all 4 or 5 mounts for damage.

Thanks for the reply. I called my mechanic and his office manager said that he would have used "DEA" or something like that, but a hydraulic mount. His opinion is the same as yours, that another mount may have gone. I have an appt on Friday and he'll have all of the mounts looked at...and at no-cost to me :)

Thanks again.

Three years is probably about the limit for an after-market replacement. Shown below is the typical mount that fails (Left front trans mount)

Anchor Mount Features & Benefits

Both natural & SBR (Styrene Butadiene) rubber provide good abrasion resistance and aging stability to ensure maximum life & performance
All Rubber material is manufactured to specific Durometer (hardness) measurements based on the vehicle's application requirements
All fasteners are made of hardened steel with heat treated Grade #5 bolts
A special Chemlock® bonding agent is used to ensure a superior rubber-to-metal bond
Hydraulic Mounts (applicable where OE) are designed for most front wheel drive vehicles, because of the transverse drive train mounting

http://info.rockauto.com/getimage/getimage.php?imageurl=http%3A%2F%2Finfo.rockauto.c om%2FAnchor%2FEngMntGen.jpg&imagekey=338700-1&width=450

So, if the mechanic tells me tomorrow that I have a mount that's bad, should I go buy a GM replacement and have them install that one, rather than the aftermarket type they ordinarily use? Would there be a significant difference in cost?

If you have the money to buy an original GM mount, that would be my recommendation. They do cost more, but also last longer. Even if you can get a lifetime warranty on the after market brand, that does not cover labor to install, which could cost more than the mount.