1985 300CD: Replace orig. starter + neut. safe. switch before they fail? - PeachParts Mercedes-Benz Forum

5cylinder · #1 08-20-2015, 08:37 PM

My 1985 300CD-T (Calif.), 30+ years old now (203,000 miles), still uses the original starter and neutral safety switch.

My question: Is it advisable to replace these two items prior to their inevitable failure? I intend to keep the vehicle for the foreseeable future.

Starter background...as of now:
A) The starter motor always turns over but to my ears, it does sound a bit like it is getting tired (3 year old Interstate battery in use).

B) There is no trouble with the starter slipping or grinding-screeching during cranking.

C) I have not noticed any starter solenoid clicking or lack of clicking.

I have replaced the starter on a 300D and so I know the work that is involved. In that case, I replaced the starter at 232,000 mi. not because it failed but because a professional M-B Tech. told me: Since you have the intake and exhaust manifolds removed for the head gasket and head replacement you're doing, it is an optimal time to replace the starter.

I am aware that, among other causes, when the tips of the starter drive wear, the timing between pull in slow rotation and full power rotating becomes incorrect and causes the starter drive to rotate at full power and impact the flywheel teeth. Translation: Fatiguing the teeth causes them to break.

So, regarding the starter...
Any thoughts about the wisdom or foolishness of replacing the starter and solenoid before either or both clearly show signs of impending failure or just quit?

Same thing goes for the neutral safety switch:
Replace it before its death is known or just let it die a natural death?

Thank ya-

leathermang · #2 08-20-2015, 08:50 PM

Uh... like they asked in Ghost Busters..... is this a trick question ?
I say wait and let them surprise you when they go out on some trip or some time when it will be much more exciting finding and getting them replaced... and probably cost a lot more than now.... keep your sense of adventure !!!
You could even take bets from family and friends on when they are going to quit on you and just how bad the situation will be compared to replacing them now at your convenience .......

mannys9130 · #3 08-20-2015, 08:51 PM

I would advise you to refurbish/clean up the starter rather than replace it. These 61x starters are very strong and well built. Stretch wrote up an awesome thread for doing this.

The NSS I'd wait on because you can usually start it in neutral if park stops disengaging it.

I'd pro actively replace the ignition tumbler before all else.

leathermang · #4 08-20-2015, 08:58 PM

The ignition tumbler is a good idea...
go ahead and buy the NSS now while you can... yours may not quit till ten years from now.....and no telling about availability then....and keep it in your emergency box in the trunk.
I suggest if you do redo your starter.....that you find a shop in a local farming community and seek out the best starter/generator/magneto shop to do it... I had mine done while I watched them... and it was really hard to get it apart.. they have the right equipment to not hurt it opening it up...

mach4 · #5 08-20-2015, 08:59 PM

Why stop with the starter and NSS - while you're at it, consider the turbo, vacuum pump, steering gear, fan clutch, injector pump, pistons, seals, transmission, flex disks, wheel bearings, alternator, differential, valves, injectors, fuel pump, oil pump, timing chain, oil pump chain, u-joint, radiator, A/C compressor, glow relay, camshaft and so forth...

It's very difficult to know how long any particular component is going to last. If you're going to be taking long road trips into largely uninhabited areas and concerned about being stranded...maybe. If you're driving is mostly local and the impact of a failure is just inconvenience...maybe push it.

You'll likely get as many opinions as there are people.

In my opinion, certain things are true PM items, timing chain for example, because the results of "pushing it" are catostrophic. Others are fix-when-broke items - for example the NSS can be bypassed to avoid being stranded.

leathermang · #6 08-20-2015, 09:02 PM

I would put the vacuum pump into the Do It Now....
when mine quit I almost did not get home without having an accident... could barely push the brake hard enough to keep from rolling through stop signs....

5cylinder · #7 08-20-2015, 09:13 PM

Ah, you good people are a joy!

leathermang:
Ghost Busters...love it!

Great point about acquiring the NSS while it is still available and keeping the old as a spare (as I often do for removed components).

I'm on the fence about re-building the starter locally or acquiring a Bosch rebuild through Pelican Parts. Perhaps I'll look around the local shops and see if I spot one that looks like a good match for a classic M-B starter.

leathermang + mannys9130:
As for the ignition tumbler:
I learned the hard lesson on that one on the 300D I mentioned. This may be hard to believe but true: I have an entire and brand new ignition assembly + tumbler and key from M-B all set aside in a box ready for install any time I darn well please! No worries.

mach4: Thanks for the chuckle!

In fact, vacuum pump has been replaced recently, fan clutch - check, flex disks - replaced, wheel bearings (front) - done. alternator - replaced within the last year, timing chain - check, u-joint - check, radiator (replaced w/Behr 3 years ago), A/C compressor (replaced same time as radiator). I ain't done it all, but I ain't been slackin' either!

I appreciate this great feedback! Thanks-

leathermang · #8 08-20-2015, 09:21 PM

Well, you clearly have not been slacking.....
that kind of PM will pay off....

my123ca · #9 08-20-2015, 09:57 PM

My starter and NSS is still original at over 300,000 miles. The solenoid is a different story though, the plastic part of the solenoid is just being held by epoxy. It just diintegrated when i rewired for a bigger alternator. I have an extra cal starter from an SD. There is a kit from mercedes to rebuild the starter. I dont know if it is still available.

mach4 · #10 08-20-2015, 10:18 PM

Quote:

Originally Posted by 5cylinder

mach4: Thanks for the chuckle!

In fact, vacuum pump has been replaced recently, fan clutch - check, flex disks - replaced, wheel bearings (front) - done. alternator - replaced within the last year, timing chain - check, u-joint - check, radiator (replaced w/Behr 3 years ago), A/C compressor (replaced same time as radiator). I ain't done it all, but I ain't been slackin' either!

Shoot, in that case, definitely do the starter and NSS...you wouldn't want to be accused of being a slacker!

vwnate1 · #11 08-20-2015, 10:29 PM

Stater life depends a lot on how well maintained the engine is : lots of cranking means shorter starter life .

The good thing is : after getting the damn thing off , overhauling it is dead simple , clean and replace brushes and solenoid (ALWAYS the Bosch solenoid and only use Bosch or Echlin new one) , grease it carefully and re install .

One of mine is still going strong @ close to 400,000 miles .

5cylinder · #12 08-20-2015, 10:29 PM

Quote:

Originally Posted by mach4

Shoot, in that case, definitely do the starter and NSS...you wouldn't want to be accused of being a slacker!

No, sireee!
I got a rep. to defend here!

On the other hand, after reading your list, I feel like I need to create a calendar for the next 12 months and get me off my couch! Hey, so long as I haven't rebuilt nearly everything, I got stuff to do!

Momentarily forgot: Earlier this year: Replaced rear axles and did complete rebuild of front end (including using Klann spring compressor - woo hoo!) and replaced original center and rear mufflers last week. Quoting Austin Powers: "Yeah, baby!! Yeah!!!"

-----------------------
On the subject of locally rebuilding the starter: Searched for a local alternator/starter rebuild joint and seem to have happenstanced upon the one that does the full monty: domestic, import, industrial, heavy duty, diesel, marine. 7 reviews between 2012 and 2015 - all five stars. Never considered doing a rebuild locally but hey, this may be the opportunity...

5cylinder · #13 08-20-2015, 10:39 PM

Quote:

Originally Posted by vwnate1

Stater life depends a lot on how well maintained the engine is : lots of cranking means shorter starter life.

On this point, I have been very gentle and crank minimally and have never had ignition/firing problems.

Quote:

Originally Posted by vwnate1

The good thing is : after getting the damn thing off...

Now ain't THAT the truth! About as annoying a job as removing the dashboard on my car and replacing the vacuum element under there!

Quote:

Originally Posted by vwnate1

...overhauling it is dead simple , clean and replace brushes and solenoid (ALWAYS the Bosch solenoid and only use Bosch or Echlin new one) , grease it carefully and re install.

Hmmm...I did not know. I must investigate further.

vwnate1 · #14 08-20-2015, 11:01 PM

My engines almost always start within 3/4 a revolution because I keep them well tuned , valves adjusted and , I know exactly how long the glow plugs stay on after the lamp goes out so I wait a little longer and am always rewarded with near *instant* starting .

I learned this habit on my very first 300CD , a '78 that was totally worn out .

I hate under dash works so I'm dragging my feet on taking the dash out of my '84 to replace the center vent vacuum chamber.....

.

mach4 · #15 08-20-2015, 11:42 PM

Dang, after reviewing your list, I'm now feeling like a slacker