Author Topic: Auto transmission wouldn't engage reverse  (Read 2801 times)

Cowichan

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Auto transmission wouldn't engage reverse
« on: August 01, 2006, 21:08:47 »
I was driving my SL and when I put it into reverse, it wouldn't
move. I was able to coast out of the parking spot and then I drove
home. It acted like it was in park when reverse was selected. I noticed that a linkage cable going to the firewall looked strange.
I could see the internal wire. The protective jacket was dislodged
from the holder. The device it went to on the firewall is about the
size of a deck of cards with this linkage going to it as well as an
electrical cable. The linkage cable descends towards the
transmission. I was able to free up the cable and reset the selector
switch and now the transmission seems to work fine again.
Does anyone know what the device is and what the linkage cable might
be so I can order a new cable.
Thanks!
Cowichan
250SL

ja17

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  • USA, OH, Blacklick
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Re: Auto transmission wouldn't engage reverse
« Reply #1 on: August 01, 2006, 22:22:14 »
Hello Cowichan,
The device is a neutral safety switch for the engine. A cable runs to the switch to interrupt the starter unless transmission selector is in "P" or "N". In addition the switch also controls the reverse lights.

It sounds like your cable kinked causing the transmission linkage to bind. Also check the plastic bushing in each end of the linkage rod from the shifter to the automatic transmission. These can age and crumble away causing the  rod to fall off or become loose.

Joe Alexander
Blacklick, Ohio
Joe Alexander
Blacklick, Ohio
1969 Dark Olive 280SL
2002 ML55 AMG (tow vehicle)
2002 SLK32 AMG (350 hp)
1982 300TD Wagon turbo 4spd.
1963 404 Mercedes Unimog (Swedish Army)
1989 flu419 Mercedes Unimog (US Army)
1998 E430
1974 450SLC Rally
1965 220SE Finback

Cowichan

  • Guest
Re: Auto transmission wouldn't engage reverse
« Reply #2 on: August 02, 2006, 09:51:51 »
Thanks Joe! Now that you mention it, I remember once
that the car started in gear. This was back when I
first got it and I wasn't used to the backwards shifting
pattern. Good thing I always use the (working) parking
brake!
Thanks again!
Vaughn

Cowichan

  • Guest
Re: Auto transmission wouldn't engage reverse
« Reply #3 on: June 27, 2007, 23:41:46 »
It turns out that the transmission had an internal problem with
a shift rod. It sheared off. I replaced the transmission with another
unit.