1984 300D transmission gearshift prevents starter to engage

I recently bought a 1984 300D. I have noticed I can move the gear shift (US auto) up and down without the car started. I believe you shouldn't be able to do this. Also where reverse is located the shifter is between Park and Reverse. Anyway I think this causes the car not to start. I can get it started no problem, run an errand, and when I hop back in it won't start. I can try to start it 5 or 6 times and it won't crank (normal glow light and buzzer). So I did an experiment and put it into N and it started right up. I did this a couple of times. Is there a gearshift switch and if so is there an adjustment to fix this problem? Thanks

Jeff

Reply to
jefftino
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Yes, there is a starter safety switch... on driver side of tranny and black thing by the privot. Sometime, your bushings on these linkages are shot or gone so the alignment is off... get these bushings from dealer...cheap enough and pop them in with help of plier.

Safety switch is easy enough to change.

Reply to
Tiger

Reply to
Wan-ning Tan

This statement is only partially true. I have an 84 300D that will only start in neutral or park. I know this because when I bought it I hadn't owned an automatic in over ten years, and the second time I tried to start it, it wouldn't start. This was because the first time I had left it in drive and used the parking brake. Oops. If you have an 80s car that doesn't have this feature, it is broken. I have also owned cars from 70, 71, and 78 that all had neutral safety switches on automatic transmissions. They weren't Mercedes, but that switch is not new technology.

You are right about the interlock that you mention concerning the brake and shifting out of park. This is a relative newcomer, but the shift linkage tied to the starter circuit is old.

Reply to
weelliott

Is that what you would call a gearshift bushing(s)?

Reply to
jefftino

No, they are two separate things... you see, the bushings keeps it align so when they fall out or deteriorated, the neutrals safety switch sometime think it is still engaged in gear... so you can't start.

Reply to
Tiger

I spent some time looking in the service manual on CD (wish I had a hard copy instead) and could not find info on the automatic. Is it in there?

Thanks Jeff

Reply to
jefftino

I was only mentioning about the interlocking, which came out in late 80s after many incidents of sudden-moving-forward (the most famous is probably Audi 5000).

The neutral safety switch on automatic transmission is old, probably older than me :-)

snipped-for-privacy@gmail.com wrote:

Reply to
Wan-ning Tan

No automatic transmission is included in any service manual... those are strictly autmatic tranny service manual.

Reply to
Tiger

Hello Jeff if you have to replace the neutral safety switch to not purchase a rebuilt one battery manufactured in China and do not work. I spent a day trying to get one of these rebuilt ones to work. Replace it with OEM only. An original equipment manufacturer

Reply to
Joe

So I went looking under the drivers side and found the linkage (I think). However I don't have ramps to jack the car up. I think I could live with it for the time being. Sounds like they must be rubber or something like that. I mean the linkage is off so the gearshift is off to the corresponding P,R,N, etc. The safety switch works. It's too bad the tranny manual is not included with the regular service manual. :-(

Thanks for all the advice.

Jeff

Reply to
jefftino

If the linkage is really loose as it plops in the hole, there is that bushing that is missing or loose. Old one is like silicone... new one is more rigid plastic that flex only enough for you to slip it in with pliers.

Reply to
Tiger

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