Tranny slop when put in Park? - PeachParts Mercedes-Benz Forum

gawlbpd · #1 06-10-2003, 12:08 PM

Does anyone else have what I can only characterize as a lot of "slop" when they put their 300SD in "Park"?

For example, when I come to stop, then place it in park, the car will slide forward, or backward, depending on the slope, maybe 6 or 8 inches. Of course, the tires aren't moving, it's in the tranny somewhere. It's unnerving, and it locks up my ignition key sometimes.

Is that the flex disk going bad, or the tranny, or both, or is it somewhat normal?

83 300SD 174K

vwbuge · #2 06-10-2003, 01:17 PM

I really don't think it is the transmission locking up your ignition key. Next time it "locks up" try turning the wheel side to side as you turn the key. I know the wheel is locked but there is a little play there.
My car also has a little slop in Park but I never let it happen. I ALWAYS USE MY PARKING BRAKE!!! Even if I'm parked on a level surface. Just a froce of habit. If you continue to park on a slight or heavy slope and just put it in park over time you will do damage to your tranny.

gawlbpd · #3 06-10-2003, 01:46 PM

Yeah, unfortunately, the rear rotors are lipped so bad that they must be under spec., and, of course the parking brake doesn't work because the pads can't reach.

I have four new rotors that are going on this weekend. Thank you Thomaspin for his website to walk me through it!!! I'm waiting for his next installment. Tom.......we're waiting!!!!!

vwbuge · #4 06-10-2003, 04:21 PM

It is not your rear pads that activate the parking brake. Do you have a w126? They are like my Subaru. The parking brake mechanism is actually a drum brake located inside the rear rotor. These mini Shoes are kinda hard to find with all the hardware. Don't worry about tackling anything brake related on a MB. They are way easy. It took me longer to jack the car and remove the wheel than it takes to replace the pads.

sixto · #5 06-10-2003, 05:14 PM

When you apply your park brake on a slope, the natural camber flexibility of the rear axlw will cause the car to move a little bit. The wheels won't roll but the body will shift on the rear axle. Same thing happens when you hang the car on the parking pawl except that the wheels will roll a little depending on how far the parking pawl is from engagement plus a little wear. 6-8" sounds like considerable wear.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

The Warden · #6 06-10-2003, 05:30 PM

Another possibility...I've found that, when I release the service brakes with the parking brake on, the front wheels move a bit. This is due to my bad guide rod mounts; when driving, the front wheels move back a little bit, and when the brakes are released and the vehicle doesn't move, the wheels return to where they're supposed to be. At first, I thought it was the whole car shifting forward like it would if the tranny was put in Park and the E-brake wasn't used, until I tried putting the tranny in neutral and setting the E-brake...it still shifted a little bit, but then stayed stable.

Just a thought...good luck!

And E-brakes are our friend...I rememebr reading a story about a guy with a Suburban pulling a trailer who stopped, put the tranny in Park, and didn't set the E-brake, and climbed under the truck to look at something. The Park gear was stripped, and the truck started rolling...ran right over him, killing him. Extreme example, but IMHO I wouldn't trust the tranny by itself to hold any vehicle, nor would I trust the brake by itself...I firmly believe that it's best to use both.