Broken Neutral Safety Switch and replacing shifter bushings
 

Worked on my daughters and sons cars today.
While we were at it I decided to replace the shifter bushings since mine were rattling.
Did the 240D's while I replaced the transmission rear seal, another story, and figured I would jack up the 300TD, place the front on jack stands and replace the bushings.
First replacing the bushings is a PITA. They are hard to get into the hole. Need some serious forcing with a screw driver. Had to take the shifter rod out of the car to get the front/tranny bushing in. Not very much room next to the tranny of the 300TD. Lots more room in the 240D, the tranny is more forward in the tunnel
The rear bushing, or shifter bushing has room around it so it is doable in the car. Otherwise you will have to remove the entire shifter assembly.
Removed the rod and installed the bushing. Reinstalled the rod HOWEVER I did not properly install the neutral safety shift lever into the metal shifter lever on the transmission. The result was when I moved the shift lever to the park position. I broke the plastic lever INSIDE the switch. Drilled the rivets out and opened it up. Broke the thing.
Now what's interesting. We have no working car.
240D drive-shaft out, LCA bushing out, battery tray out
560SL idling rough and I hope the air pump clutch made the terrible noise, if not It might be the timing chain rails :eek:
65 Mustang in the middle of installing the AC system.
300TD neutral safety switch.
Tomorrow My sons friend will take us to the dealer for the part. Then I promise I will not touch the 300TD until the 240D and Mustang are on the road.

Tomorrow night is the Barbecue get together at the West End in Dallas. Got to get the car running.

What I learned, besides don't work on the only car you have running.:D :D

To replace the shifter bushings it is easier to remove the rod and do the forward/tranny bushing on the work bench. To remove the rod, remove the bolt/nut assembly holding the shifter lever to the transmission rod that comes out of the tranny.
Remove the rod toward the rear.
When putting the rod back on the shifter shaft, ensure the neutral switch rod is inserted into the shifter rod that attaches to the tranny. The neutral switch has about a 90 degree movement and you can position the black plastic switch lever as you install the shifter lever.
Install the bolt/nut unit on to the tranny shaft and tighten.
IF you break your switch your car will not start and the backup lights will not illuminate.
If the black plastic lever can go around 360 degrees, you broke the lever inside the switch.
You can take the switch off the tranny without draining the fluid. It's attached with 2 10mm bolts. It does require a small ratchet to remove them. Not much room in the 300TD transmission tunnel.
To do it rotate the white electrical connection locking ring. Rotate the front part clockwise until the tabs on the black connection are free. Then pry the switch out with a screwdriver. 2 would be best. Unscrew the 2 bolts and the unit will lift off. The shift rod lever must be off the tranny to remove the switch.
Have friend drive you to the dealer for your new part and install it.

Dave

A picture of the broken switch.

eeewwooooooooooodogggeeeeee!

Good info!
the 240D needs the shifter bushing sometime in my next life!

Was going to steel the NSS from the 240D to get the 300TD running to pick up a new one. Of course they are different.
The 83 240D has the W4B 025 or 722.117 transmission.
The 82 300TD has the W4A 040 or 722.315 transmission.

Dave

Some pictures from a car I worked on
 

Some pictures from a car I worked on.

www.**************.com sells a little homemade tool that makes installation of the bushings easier. I know, sorry to mention this after the fact. :D

More pictures
 

from the same car.

I just got my new(to me) '84 300D tonight. The back-up lights don't come on and I can start the car in any gear. Is this a bad neutral safety switch? They are a royal PITA to replace.

yep

Thanks

i took my NSS apart after I R&R'd it. What had happen was a little plastic piece broke off inside and the shift rod would move the switch but the switch wouldnt contact the pins/wires

Does the NSS have a seal, or leak any fluid when removed? I have one ready to be installed (back-up lights come on halfway between park and reverse only).

Nope. It just has three bolts that are kinda hard to get to because there's very little room between the side of the tranny and the frame. It doesn't mess with the innerds of the tranny, just bolts on to the outside. One lesson I learned the hard way, the electrical connection doesn't just pull off. If you examine it closely the white ring turns then the black connector comes off. I almost broke the black connector trying to pry it off

Quick solution for the non-functioning neutral switch: jumper the terminals for the starter lockout, terminals 3 and 4 from the diagram I have, at the switch. This way you'll have your car up and running until you get a switch. Of course, you won't have backup lights, but that's minor. Just make sure to always press the brake when starting in case it is in gear.

As for the fellow with the non-functioning backup lights, drill out the rivets and clean the contacts. Then fasten it back together with some small screws. Heck of a lot cheaper than buying a new switch.:)

thats a lot of work for a $26-45 dollar part. I would just buy the switch..i have a 722.303 trans and my switch was only 26 dollars.

check www.***************

That's a much nicer price but will an off brand perform the same as the name brand in this case?

I was reading this tread and seem like my problem is related to this neutral switch. My neutral start switch is leaking fluid from the rod, the lever from it is not connected to anything and rotates freely, i can pull the lever entirely out with the rod from the tranny and the fluid starts coming out, if i put it back the fluid stops. I can see a seal. I'm not sure where the other end of the lever connects to. the car starts and i can move it back and forth. Also i noticed that the accelerator pedal has this section like a lever that is touching the exhaust pipe, but not connected to anything either.. is that where the lever from the tranny is supposed to connect to? any ideas how to approach this? any help it's appreciated.

Answer
 

Data needed:
YEAR
MAKE
MODEL


The NSS is not your main issue at this moment.

This lever is your gear selector = if it falls off...:eek: :eek: :eek:

The problem is inside your transmission, a fastener has come loose, allowing the arm to come out.

Remove the transmission oil pan and check for loose/missing fasteners or mechanical damage.


Have a great day.

Neutral Safety Switch
 

Neutral Safety Switch how would I go about replacing one?

And how much should It cost for a shop too replace one?

:EDIT: 1984 300SD.

Thanks,

Tony

Answer
 

Transmission:

Broken Neutral Safety Switch and replacing shifter bushings
http://www.peachparts.com/shopforum/showthread.php?p=646647

Replacing all shifter bushings on W126 - p.1
http://www.peachparts.com/shopforum/showthread.php?t=112582


If the shop charges more than one hour Labor = run away, they are crooks.

Any idea if the NSS is the same between 1986 300SDL and 1983 300SD?
On APE the parts seem the same.

I am diagnosing "no reverse lights" on my newly acquired 300SDL.

Thanks.

Answer
 

W126.120 300SD
MB# 000 540 47 45

W126.125 300SDL
MB# 000 545 49 06

Thanks for the follow up reply.

I am not really sure what the answer is here.

The part numbers listed appear to be different, but possibly the same. When I look the parts up I am given the same part number. It is also possible that I order both numbers listed here and get the same box. yes?

I am weighing if it is worth the effort to remove and install 2 switches.

Again, thanks for the help.

On my 1975 280c, I have removed the NSS however i can't seem to be able to put the new one in... I have the correct part and everything just cant figure a way to get it over the rod. Any ideas??

Hmmm
 

More data = pictures needed for this issue/question.

Where to find NSS electrical Plug (Neutral Safety Switch)
 

I saw this thread and thought someone could help. I have a 1980 300SD and the NSS switch PLUG has deteriated. The switch part number is #000-545-4606, but I can't find the electrical plug part number that goes in it. Even the guys at Auto****AZ and Shumaker Mercedes don't have a clue. Any help is appreciated.

I just looked throu the EPC, and could't find anything on it. The EPC for the 116 is slightly less organized than the 126. Try getting in touch with Lee or Roy here on the forum, I'm sure they can find something for you.

NSS Plug
 

How do I get a hold of Lee or Roy?

Hello
 

You came to the right place for answers..

insulating sleeve, NSS
MB# 000 546 08 45

Note: 100 in North America..


.

NSS Electrical Plug
 

Hi all

What I need is the part number or where to fing the NSS PLUG. Do I have to buy part of a wiring hanress? Mine deteriated and falls off.

Answer
 

This is the PLUG/hard shell that holds the spade connectors which you attach to the NSS.


insulating sleeve, NSS
MB# 000 546 08 45

Note: 100 in North America..


.

NSS Plug
 

Ahhh Sooo.

Thanks!!! Do you guys carry it?

Answer
 

SPECIAL ORDER = we can get it..

Check with your local MB dealer, their price should be $2.00..


.

Recycled
 

Because I replaced another one today.


.

Hello all, I have the rolling in park symptom and a sloppy shifter and my shifter vibrates and rattles. I think i also need to replace bushings. I have a 83 300d. I saw another site had 2 smaller bushings not listed on this site for a total of 6 bushings. What I see here is (2)115-267-12-50-M200 and (2) 115-992-03-10-M36. Is this all i need?
Thank You

I got the 2 bushings on the shift linkage replaced, under the car. That was a PITA to get the bushing in the hole under the shifter. I actually gave up and cut the flange off one side, done. There is actually a hard stop at the gears now. No more rolling backwards or rattling.

Tried to change shifter bushings, broke Neutral Safety switch
 

OMG I finally undid the damage I'd done to the SD. It started last week when the car slipped out of gear at an intersection. At first I thought I'd lost the tranny then I recalled something about loose shifter links being common in mb diesels.

I got home. Sure nuf, worn front bushing. Gone actually. Long gone.

No biggie I thought, I'd just slip some 3/8" fuel line over the link rod. I have a lot of scraps. So I did it. I should have read dmorrisons post about not putting the neutral safety switch in correctly and it broke just like his as I shifted into park.

I was pretty bummed as I put it all back together and the car didn't start. Rather than debugging I went straight to the forum. Arg, I broke it. A reverse light check verified the bad switch.

So I ordered one. And a new bushing and clip. I felt tight so I rolled the dice on the Vemo instead of the MB at Pelican. It looked pretty good. As I put it on the lock ring fell off. I couldn't get the cable on for the life of me.

So I took it off and made sure I knew how to connect it all together before installing it again. There was a little spring loaded rivet under the locking ring that made it impossible to put the ring back in while it was in the car.

Did I mention there isn't much room? :(. My neck hurts.

Ok, got it all back in and the cable is locked down. Car starts. Drives and shifts nice. For some reason my car likes to downshift as I slow down to a stop. It didn't do this before.

No harm but somehow messing with the link bushing changed something. Hard to believe it can be the new Vemo switch.

Anyone know how to bypass the switch without going under the car? I'm worried the locking will fail on the cable and leave me stuck. I double checked it and it was locked but I'm just paranoid. I feel like I should come up with a zip tying scheme or put a spring between the tunnel and connector to make sure the dang thing doesn't come off. I pulled on it and it seemed sturdy.

I'm getting too old for this stuff. I may have to just call it a day and buy a cdi. I certainly have saved enough money over the last decade driving these tanks to get something newer.

Installing bushing
 

Forgot to mention. I saw the tools offered online for installing the bushings. I took the link arm off the tranny and pressed the bushing in on a vise with a big socket.

It isn't a big deal taking it all apart.

I guess I wouldn't have broken my switch if I hadn't pulled the link arm.

Ok, nosed around here. Looks like the easiest way to get the car bypassed is to connect 12v to the little terminal on the starter solenoid. I'll toss an alligator clip in my toolkit.

I don't remember farting around with my NSS last time I installed shifter bushings. The installation tools available take a 60+ minute fuster cluck session and turn it into a 10 minute slide in and slide out deal. The only thing that may be temporarily removed is the rod from the shifter to the trans and that is only to install the bushings.

Right, because you don't have to. I'm an idiot and I thought I'd take it all apart and bring the link arm into the garage where I have a vise. I didn't buy the custom tools and boy oh boy, I wish I had after I turned a bushing swap into a NSS swap. While taking off the arm I misaligned the NSS toggle that goes through the arm...just like the OP.

Now my transmission has a clunking downshift from 2-1 when approaching stop signs at less than 10mph as I brake. I'm not sure what did this but maybe I bumped the modulator when I was down there and started a leak. I'll need to hook up a vacuum gauge tomorrow and go for a drive.

It looked really easy to just take that shifter arm off rather than buy that plier press tool that I'd only use once. Using a bolt, washer and 17mm socket to press the bushing in May have been a good compromise.

This is something I've done on 3 different 240D's I've owned. There are a total of 4 bushings. I've found replacing all bring the factory ride back. The bushings are stiff and I bought a tool from Kent Bergxxxxx which was nothing more than a series of washers, nuts and a coupler which pulled the bushing into place. I recommend highly putting the bushing into a pot of boiling water for 3 minutes prior to installing. Makes installation SOOOOOOO much easier.

Hey,
Apparently he sells a plier tool now. It was $60 with some bushings. Again, a bargain compared to the snafu I made up for myself. But, as I said Im an idiot sometimes.

I'm shocked the bushings in my 4 spd 240d never went out. They get a lot more action.

Anyhow, I just got out of under my car. The clunking shift was the hose that I knocked off the modulator. I'm shocked the up shifts were so smooth without vacuum. Maybe that's a bad sign of things to come. I recall unhooking vacuum gave me some nasty harsh shifts. It was shifting quite well without the line.

Nothing is forever.