Bosch SR59X vs SR459X starter for M116

[sjefke]

I need some advice on starters for my coupe's 3.5 M116 engine. I bought a new starter two years ago (Bosch SR59X) and it is developing problems. First time start: solenoid clicks but no starter running. Second try (or third): solenoid clicks, and starter starts running (normal, but after a short delay). Sounds to me that it has an internal problem (solenoid-starter contact or so). I am pretty sure it is not the battery because once the starter runs, it runs at full speed without a low voltage groan.

So, my simplest solution (time is precious) is to get a new starter, but then I found this on a website that describes 2 different types: a thin one (Bosch SR59X currently in my car) and a thick one (came out of my car) called SR459X. What makes me nervous is the statement that the SR59X is a gear reduction type "but will do the job". Sounds to me I need the bigger one.

http://www.redlinemotive.com/store/replacement/wizard.asp?year=1971&make=MB&model=280-SEC-002&category=F&part=Starter

Questions:

a) Has anybody had comparative experience with these two types (Bosch SR59X vs SR 459X)?
b) Should I get the Denso instead and is that the thicker type?
c) How can I make sure that I get a SR459X?

Thanks,

Bert

[Tomguy]

The SR59(x) is the correct starter that was put on all cast-iron m116 and m117 engines, and early aluminum 5.0 and 3.8 as well. It's the one my 4.5 has and it starts on a dime every time.

[sjefke]

Do you have the thin skinny one or the thick fat one?

Bert

[Tomguy]

I wouldnt call it skinny, but I dont know how fat you're calling fat. I have a picture @ home I think I can post in a bit.

[sjefke]

Finally had time to solve my starter problem. I bought a remanufactured unit from Ebay and pulled my two year old Bosch SR59X out of the car. Attached are pictures. The left one is the Bosch SR59X that I bought 2 years ago and it still has all the official Bosch stickers on it. Turns out it is about 1 inch thinner in diameter than the starter that I now have (3 inch versus 4 inch for the "fat" starter). It is also shorter (see picture). The right one matches my original starter size (and is a tight squeeze between exhaust manifold and chassis).

Not sure whether the size made the difference because I also heard something rattle in the starter once I pulled it, but the fat one I put in now feels a lot heavier and stronger than the dinky SR59X that is now in my basement (I may strip and check it some day).

Car starts like a charm again. Problem solved for $114 and an hour of wrenching time.

Bert