Reverse gear in automatic

[n/a]

Hi everyone
I took the car for a drive in the mountains on the weekend and dropped in to see some friends. I parked my 230SL on their fairly steeply sloping driveway with the nose pointing downwards. I was there for about 8 hours and when I went to back the car out it wouldn't move. The motor revved but the car wouldn't reverse up the hill. Fortunately, it was football grand final night and there were a few blokes around to give me a push. When the car was given a little help to start moving it was fine. No problems with the 3 hour drive home and the car reversed up my own fairly steep driveway as usual. This has never happened before. Any ideas?

Thanks, as usual! Mark

1965 230 SL

[Cees Klumper]

Did you put the handbrake on or was all of the weight of the car on the automatic transmission in "P"?

Cees Klumper in Amsterdam
'69 white 280 SL automatic

[rwmastel]

Mark,
I have not been parked on a steep slope, Ohio is mostly flat, but I would recommend making sure your parking brake would hold the car while in Neutral.  Once held by the brake, then put it in Park.  Is this your procedure?

Rodd
Powell, Ohio, USA
1966 230SL, Euro, Auto, Leather, both  tops
1994 E420

[George Davis]

Mark,

I'd guess that while parked on the slope, the transmission pump pick-up was uncovered by the ATF flowing forward.  With the pick-up uncovered, the trans pump wouldn't develop any pressure, and without fluid pressure it's not possible to engage any gears.  Total guess on my part, because I have no idea where the pick-up is located.

George Davis
'69 280 SL Euro manual

[n/a]

Hi Cees and Rodd,

The parking brake was on and there was no effort shifting from park to reverse or neutral. The car just wouldn't move until it got a push and then it was fine. I think I've tracked down the problem. I mentioned this to a friend with many years experience with older Mercedes cars. He asked me if the car was sitting for a long time on the slope, had it been raining and did I give the handbrake an extra 'notch' to hold it. Yes to all of these questions. He has found that the rear brake shoes can occasionally jam under these conditions and cause exactly the problem I had encountered. This would explain why it has not occurred before and why there has been no problem since.

Another one to chalk up to experience.

Mark

Ps. I used to live in Ohio, Rodd. It is flat, isn't it?

1965 230 SL

[ja17]

Hello Mark,
Be sure to check the fluid level with the transmission warm and the car running on perfectly level ground. Next check the reverse band adjustment. A large 22mm lock nut may become loose allowing the 10mm reverse band adjustment bolt to loosen. This 22mm locknut should be a checked for tightness occassionally. To re-adjust the band, the 22mm locknut should be loosened and the 10mm adjuster bolt should be just snugged (clockwise) then back the 10mm adjuster bolt out (counterclockwise) one and a three quarters turns (1 3/4). Tighten down the 22mm locknut. If the adjuster bolt becomes loose the transmission may be slow to go into reverse or may not reverse at all. If the adjuster bolt is too tight it may cause wear to the reverse band.
Here is a photo of the 22mm locknut and 10mm adjuster bolt. Good luck!


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Joe Alexander
Blacklick, Ohio