1994 E320 Neutral Saftey Switch installation help request. - PeachParts Mercedes-Benz Forum

john90290 · #1 02-15-2008, 11:06 AM

I have the new switch and was planning on installing it this weekend...the only problem is that I cannot find any details about the switch in my CD-ROM manuals.

Any suggestions as to which module I should look under or any tips on the install would be great.

deanyel · #2 02-15-2008, 03:05 PM

It may not be there - could be considered transmission related and included there. The Haynes manual has it, I suspect Alldata has it (at some public libraries) and there's quite a bit of info here with a search. It is a good idea to get some instructions - there's a sort of intricate alignment issue.

280EZRider · #3 02-15-2008, 03:29 PM

I am not familiar w/your model; however if it is anything like the W123 cars, disconnect the linkage, then remove the adjustment plate while noting the position of the adjusting screw, and then remove the switch. It's not really difficult if you have enough light and room to move about.

Arthur Dalton · #4 02-15-2008, 08:03 PM

The switch is tight, but straight foward to replace.
It is mounted to the trans with 2 10mm bolts. The bolt holes are oblonged for rotational adjustment.
The only tricky part for first timers is the plug has a white locking ring on it that requires you to turn the ring to the unlock position in order to unplug the harness..and there is also a pin in the sw. acyating lever that has to line up with the hole on the shift arm to lock that into proper location upon reassembly..but that is pretty much evident once you are down there.
Adjustment is correct when you have a starter engagement in both N and P and back-up lamps in R.
You may also want to take a look at the shifter rod rubber bushing for wear while you are there ..they are usually worn and simple/cheap to replace.

emerydc8 · #5 02-15-2008, 08:55 PM

You may find that dropping the transmission pan makes it easier to get to the bolts of the switch.

Arthur Dalton · #6 02-15-2008, 09:01 PM

If anything , disconnecting the rear mount would be easier than dropping the trans pan for additional clearance.
Dropping the pan means draining/refilling the fluid.. unless you are doing a Fluid/Filter change anyway............

richard28 · #7 03-31-2008, 10:27 AM

I had a local garage, not mb specialist but with a good reputation, replace the NSS two years ago after I couldnt start my car on cold days in either P or N. Many months after replacement, just for fun I tried to start the car in N, but it wouldn't start; it only starts in P. Would that suggest the NSS was bad or not properly aligned? Thanks.

Arthur Dalton · #8 03-31-2008, 10:35 AM

Possibly, but not likely..

Try R and see if you have Back-up lamps..if you have start in P and lamps in R, most likely the sw is in adjustment.

What happens to these NSS is they get water in them from the road and in cold weather, the water freezes. stopping contact on the switching points. until the sw warms up.

A test for N adjustment is to hold the key in START position with left hand and move the shifter on each side of N..if it works off N center ,than the adjustment is likely just off a bit.. ..

richard28 · #9 03-31-2008, 10:47 AM

Thanks Arthur for another expert reply (to which we all are grateful).

Arthur Dalton · #10 03-31-2008, 10:48 AM

You are Welcome.......................................

EricSilver · #11 04-26-2008, 11:14 PM

I pulled the switch, removed the black lever, and reinsterted it to match the position of the old one. After reinstalling I still do not have normal start in Neutral, and was worried until I read this:

Quote:

Originally Posted by Arthur Dalton

A test for N adjustment is to hold the key in START position with left hand and move the shifter on each side of N..if it works off N center ,than the adjustment is likely just off a bit.. ..

I tried it, and the car started in Neutral, so it appears to be an alignment issue, which I may or may not correct.

Overall, this was not nearly as difficult a repair as I thought it would be. Start to finish required about 30-35 minutes. The key is small tools -- a 1/4" ratchet is essential, with a 2"-3" extension for removing the linkage bolt. All bolts are 10mm.

For easier removal/replacement of the switch's top bolt, the shifter should be in Neutral. For easier removal/replacement of the linkage bolt, the shifter should be in Park.

EricSilver · #12 03-31-2008, 12:29 PM

Quote:

Originally Posted by richard28

I had a local garage, not mb specialist but with a good reputation, replace the NSS two years ago after I couldnt start my car on cold days in either P or N. Many months after replacement, just for fun I tried to start the car in N, but it wouldn't start; it only starts in P. Would that suggest the NSS was bad or not properly aligned? Thanks.

Uh-oh. Add that to my list of concerns.

I think it was a mistake for me to wait for warmer weather to do this repair, since, because it is not cold, I will not be certain the repair worked. Hopefully it will still be chilly this weekend, when I do it.

EricSilver · #13 04-26-2008, 10:33 AM

I am doing this repair now.

I have the shifter linkage unbolted, but the linkage it not sliding off the metal pin/bolt that connects it to the switch. The outer part of the 'U' shaped connection slid over the bolt/pin but the inner part has not. Before I try to pry it off, is it supposed to slide off, or does that pin/bolt come out as well?

fred1948 · #14 04-26-2008, 12:05 PM

Quote:

Originally Posted by EricSilver

I am doing this repair now.

I have the shifter linkage unbolted, but the linkage it not sliding off the metal pin/bolt that connects it to the switch. The outer part of the 'U' shaped connection slid over the bolt/pin but the inner part has not. Before I try to pry it off, is it supposed to slide off, or does that pin/bolt come out as well?

I'm not sure exactly what you are trying to describe. You have to completely remove the clamp bolt to be able to slide the arm off the shaft. Also, when you get it off look at the plastic arm on the switch (which engages the metal arm) and you will see a small hole that is intended to be used to align the switch. With the gear selector in neutral, the hole in the plastic arm lines up with a hole in the switch body. Insert a pin to align the two holes before you tighten the switch to the transmission. If this isn't clear, do a search and you will find some diagrams.

EricSilver · #15 04-26-2008, 12:21 PM

Fred, thanks.

I resoved it and got the lingage off. The geometrically-shaped pin(?) that goes to the transmission had to be turned a bit to align it with the oval shape of the linkage. After that, I was able to get the linkage off.

Thanks again.