300E Gear shift position sensor
 

I have a 1990 300E and have an issue with my gear shift position sensor—or whatever it might be called. About 60% of the time, my car won't start when it's in Park, but I can shift it to Neutral and it starts perfectly fine. So I presume there's an obscure switch somewhere that isn't sensing the fact that the gear shift is in Park. I'm not sure where that switch might be, but if anyone could help me solve that issue, I would certainly be very grateful.

Thanks in advance!!

It is called a neutral safety switch. More than likely your shifter bushings are bad. It creates enough gap that you really got to jam it forward to get it to click.

Check the bushings first before condemning the nss

I would probably have to concur with the diagnosis of worn bushings. So...what does it take to change the bushings. I'm pretty handy with the wrench, but I've never disassembled a console. Do you happen to know of a good set of instructions that would be of some help?

Everything is accessed from under the car. Drive up on some ramps, and crawl underneath.

Buy oe (genuine MB) bushings only, they fit well and are very cheap. There is the bushing tool you could buy, it will probobly make it go in like a snap.

Remove them one at a time by lifting on the metal clip, then sliding it out, Soak the new bushes in hot water to make them more flexible. Insert them in to the "bushing tool" ( not sure what its called) and pop it in.

It will all make perfect sense when you see it. Its very straightforward.

Wow! I certainly appreciate your help. I just ordered the bushings for $0.99 each, and the retainer clips for another $2.49 each. I should have the job done before the end of the week. Thanks tons for your knowledge and insight...I certainly do appreciate it!

These are attached to the side of the transmission and connected to the linkage that you bought the bushings for:

124.026 NSS

124.030 NSS

Neutral safety switch
HELP! S-320 will not start! but finally got to start with direct power to starter - Benzworld.org - Mercedes-Benz Discussion Forum

Neutral safety switch - Benzworld.org - Mercedes-Benz Discussion Forum

Neutral Safety Switch - Wrench Log - How I Did It

You can go to any auto parts store and ask them for a bushing installation tool. It should be for rent.

If no tool, don't be afraid to trim the bushing a bit. It's really tough to get it to pop in.

It's a real pain to install the bushing without the tool pictured here. Some have had good luck with a socket, bolt, nut and washer but the easiest is to use the tool. It costs about $50. Very doubtful that any local auto parts store would have this tool to rent or purchase. You might find the tool on the member tool rental list of this forum. Mark

I found these pictures on a competing website posted by user name Winston. This illustrates the socket, bolt, nut and washer installation method (google "Mercedes shift bushing tool helper" and you will find the post). You will have to remove the shift lever from the transmission and reinstall it properly in the neutral safety switch with this method. Mark