Broken Neutral Safety Switch and replacing shifter bushings - PeachParts Mercedes-Benz Forum

dmorrison · #1 06-03-2004, 11:57 PM

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

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.

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.

unkl300d · #2 06-04-2004, 12:14 AM

eeewwooooooooooodogggeeeeee!

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

dmorrison · #3 06-04-2004, 12:36 AM

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

whunter · #4 10-16-2005, 07:06 PM

Some pictures from a car I worked on.

SD Blue · #5 10-16-2005, 08:06 PM

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

whunter · #6 10-16-2005, 08:19 PM

from the same car.

sailor15015 · #7 12-20-2005, 06:49 PM

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.

Diesel Giant · #8 12-20-2005, 07:04 PM

yep

sailor15015 · #9 12-20-2005, 07:16 PM

Thanks

JamesDean · #10 12-20-2005, 08:01 PM

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

rg2098 · #11 12-20-2005, 09:33 PM

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).

sailor15015 · #12 12-20-2005, 09:41 PM

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

KCM · #13 12-20-2005, 10:20 PM

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.

JamesDean · #14 12-20-2005, 11:18 PM

Quote:

Originally Posted by KCM

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.***************

sailor15015 · #15 12-20-2005, 11:35 PM

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