123 chassis starters

[sokoloff]

I need a new starter for my 240D. In looking at the various parts house websites, they list a Bosch starter SR61X light duty starter for the 240D and a Bosch SR67X heavy duty starter for the 300D. Both are the same price. Are they interchangable and should I get the heavy duty one vs. the light duty one? Plus, the core charge is less for the heavy duty starter.

Len
'83 240D

[JimSmith]

Len,

The starters are interchangeable. I put the heavy duty one on my 1982 240D, which I bought from Fastlane, and it fit precisely. The car starts in near zero *F weather, no problems, and has 315,000 miles or so. Go for the heavy duty one. Jim

[sokoloff]

Thanks Jim - that's what I wanted to know. BTW, I see that starter bushings are offered too. Do I need one or two of them with the new starter or are they only for rebuilding the old one?

Len

[leathermang]

I happen to have taken my 240 starter to an alternator shop two days ago... they took mine apart... said the brushes were fine and were amazingly thick.... and showed me the two screws which had finally loosened up and were arching at the top of their thread...
I have it apart because they happened to have a 240 starter which matched the serial numbers on mine which someone had ordered and not picked up... got it for $100....
Those bushings are for fixing the old one.....
Are you opposed to fixing the starter yourself ?

[sokoloff]

No, not opposed to fixing it myself, even though my son always says that in my case, electrons are not my friend. What all is involved. The problem with mine is that the clutch is slipping. I sometimes have to start it five or ten times to get it to catch.

Len

[kerry]

Autozone carries one for around $100. Order one for an 84. The 85 # they use is for a California model with the trap oxidizer.
No clutch in a starter. It's the solenoid.

[leathermang]

Electrons can not be any more unfriendly than they are to me... I hate electricity....
The good news is this is a mechanical project given your symptoms...
The shop manual does not show how to fix the starter.... I have looked... and put off putting mine back into my 240 because my backup starter off a 300 I may shortly need to power my new DC welder...
I feel I need to explain why I did not tackle the starter myself in the first place.... since I have fixed plenty of American car starters... This is a Bosch unit... and in the back of my mind I keep seeing the admonition from Mr. Muir in " How to keep your Volks alive for the Complete Idiot" that the VW Bosch starters were very complicated and required too many special tools to work on.. he, the ultimate do it yourself advocate, said " go buy one and let the pros rebuild it"...
But since I had a chance to stand there and watch them take it apart and inspect it... I will be fixing the old one myself...for back up...since it can back up either the 300 nonturbo Welder or my 240....
But with your symptoms... you probably just need to get the solinoid apart.. or put a new one on... usually on a solinoid you either have a broken return spring... or the copper washer in the end has gotten eaten up by arcing.... often all you need to do is clean and file it... or turn it over to the good side...
Give me a day and I will get the insides of mine cleaned and photographed...
In the mean time... if you are going to look into the actual starter you are going to need a hand impact wrench with a correct fitting end on it...

"five or ten times to get it to catch"... Could this be a bad spot on the ring gear ? If it sounds like a slipping clutch ? Does a bad solenoid sound like a slipping clutch?

[leathermang]

What does a slipping clutch sound like?

[sokoloff]

What happens is that the starter spins but doesn't engage the ring gear. When it does engage, it fires right up. I may have chosen the wrong term, but was told that what is happening is that the shaft that turns the gear on the starter that engages the ring gear is slipping. I thought it was referred to as the clutch. Starter has about 130,000 miles and ten years on it.

Len

[Ken300D]

The Bosch rebuilds sold by the WorldPac distributors like FastLane seem to be a good quality rebuild and a fairly efficient balance of money vs. time (to rebuild it yourself).

But I base that on my limited experience with one vehicle's starter issues, and three years of reading other experiences here in the Forum.

Ken300D

[Maki]

Len -- I replaced the pinion gear assembly on the starter in my '82 300cd four years ago. It was doing the same thing I surmise your starter is doing. The car also had about 130,000 miles on it at the time.

I can only offer my own experience, which is that a new pinion solved my problem -- the starter has functioned without a hiccup since the repair for 60,000 miles.

The starter in my '87 Audi (VAG product) has a gear reduction system that does make it fairly complicated. The Mercedes OM617.952 starter is not such an animal. I found it pretty easy to figure out once I opened it up and studied how it engages. I had some experience replacing starter drives on old Fords going in, which might have helped

Don't worry about the electrons -- you don't have to mess with the motor guts. The armature can stay in the case while you make repairs to the business end. The solenoid does have to come off, as I recall.

The starter drive pinion assembly is pretty cheap; I think it cost me $20-something back then. Might be a little more now.

Russ Maki
'82 300cd
'82 300td

[sokoloff]

Thanks Russ. This pinion gear assembly - is it a dealer only item? I didn't see anything like that listed on the World Pac sites.

Len

[leathermang]

With your description I am betting the solinoid will fix your problem... since when it does engage it starts right up it does not sound like the gear is stripped or anything...

[sokoloff]

There is a whirring sound every time it doesn't start. Then when it does engage, it fires right up. If this still sounds like solenoid problem, is there a way to test it?

Len