Gear reduction starter for W126 diesel? - PeachParts Mercedes-Benz Forum

New2MB · #1 03-15-2006, 03:47 PM

Does anyone know where I can get a gear reduction starter for an '87 300SDL?

1985 300SD Sady · #2 03-15-2006, 04:02 PM

Ive heard they sell them here > http://www.mean-green.com/products/starter.html

But, that may only be for the 617, not the 603? Someone?

New2MB · #3 03-15-2006, 04:17 PM

Quote:

Originally Posted by 1985 300SD Sady

Ive heard they sell them here > http://www.mean-green.com/products/starter.html

But, that may only be for the 617, not the 603? Someone?

Their catalog only shows one for 74 - 84 and they don't like to answer emails so I can't figure out if they'll custom make one for me.

1985 300SD Sady · #4 03-15-2006, 06:43 PM

Quote:

Originally Posted by New2MB

Their catalog only shows one for 74 - 84 and they don't like to answer emails so I can't figure out if they'll custom make one for me.

Yeah, from what I hear they are terribly hard to get ahold of and dont really run a very good business

ahwell.

pawoSD · #5 03-15-2006, 08:02 PM

So are these actually a good item? My starter probably has a couple years left (it still does ok in the cold) but when the time comes I'd consider one like that company sells if it would be an improvement. I take it all the advantage is in more consistent cranking/speed? and the lack of huge current draw on the battery? Explain please.

New2MB · #6 03-15-2006, 10:50 PM

Quote:

Originally Posted by pawoSD

So are these actually a good item? My starter probably has a couple years left (it still does ok in the cold) but when the time comes I'd consider one like that company sells if it would be an improvement. I take it all the advantage is in more consistent cranking/speed? and the lack of huge current draw on the battery? Explain please.

I'm no expert on the subject but as I understand it there is a gearbox on the starter that makes it easier for the starter to crank because of the gearing. It seems to me that this would cause the engine to turn over slower but the people that own them claim it cranks faster. I'm not sure how that would work. It's like when you're riding your bike and you shift into an easier gear, you have to pedal faster just to maintain speed. Maybe they are hearing the starter crank faster and they just assume that the engine is cranking faster? What sold me on it is that I live in a cold climate and people are saying that with a gear reduction starter they can start their diesel in very cold temp's without plugging in. I'd pay the extra money for that.

pawoSD · #7 03-15-2006, 10:56 PM

Well, I think that it has a motor about 1/3 the power of a normal starter but has a gear reduction of 4.4, and the smaller motor is a lot faster, so it more than makes up for the speed reduction, and the overall output of the assembly is probably consistantly faster than using a direct drive starter. The smaller but faster motor means a lot less power is drawn off the battery, so it can run longer and faster, especially in the cold. I wonder what it sounds like, its probably pretty cool.

I'll have to consider getting one in the future.....

Ralph69220d · #8 03-16-2006, 11:46 AM

My guess/opinion is that with the same battery you are going to get slower cranking speeds with the reduction gear starter. Generally, reduction gear starters are used in applications where the engine is very hard to turn over, that is, more pistons, more compression, etc. My opinion is that if the engineers called for a direct drive starter in the new car, then that is what you need. A new or high quality rebuild (rebuilds are a gamble; they are generally bench-tested under no or low load conditions) direct drive is the way to go, in my opinon.

New2MB · #9 03-16-2006, 01:03 PM

Quote:

Originally Posted by Ralph69220d

My guess/opinion is that with the same battery you are going to get slower cranking speeds with the reduction gear starter. Generally, reduction gear starters are used in applications where the engine is very hard to turn over, that is, more pistons, more compression, etc. My opinion is that if the engineers called for a direct drive starter in the new car, then that is what you need. A new or high quality rebuild (rebuilds are a gamble; they are generally bench-tested under no or low load conditions) direct drive is the way to go, in my opinon.

Did the gear reduction starter on your car perform better than the OEM? I'm in Michigan so I really like the cold weather peformance, at least what I've heard about cold weather performance.

Ralph69220d · #10 03-30-2006, 08:05 PM

The only reduction gear cars/trucks I have had are all Mopar's (Dodge) from the 60's. The V-8's were all relatively large displacement engines with high compression ratios (my '63 Polara 500 383 had 11:1 c/r). So a reduction gear starter was used to turn them over; but, it's a tradeoff, they actually would turn over quicker if they had direct drive starters, but the greater torque with the reduction gear ensured they'd turn over fast enough to start. Without the reduction gearing if the motor didn't fire fairly quickly the battery would run down pretty quick. So, in my opinion, stick with the starter engineered for your particular car, have a good battery / connections, engine in tune. Diesels do like to be spun fast to start and the reduction gearing slows the spin of the flywheel.

pawoSD · #11 03-30-2006, 08:08 PM

What if the motor in the reduction starter spins VERY fast, and is actually giving an overall output from the assembly thats faster than a stock starter?

Ralph69220d · #12 03-30-2006, 08:22 PM

Quote:

Originally Posted by pawoSD

What if the motor in the reduction starter spins VERY fast, and is actually giving an overall output from the assembly thats faster than a stock starter?

Sure, that's possible, but, if the main starter motor can spin the reduction gear (depending on the ratio) so fast as to overcome the gearing, I'm guessing you don't need reduction gearing. In reality, I believe, to have such a starter that could perform like that then you don't need the extra complication of the reduction gearing; plus, you lose a fair bit of the power in such a setup to heat generated by the faster spinning starter motor and in the reduction gearing through friction.

boneheaddoctor · #13 03-30-2006, 08:33 PM

more torque at near stall speeds than a direct drive starter....a DC motor isn't nearly as efficient at slow speeds...even with a reduction it CAN spin faster that a direct motor..OEM didn't do it becasue these are more complex and therefore more costly to produce. Remember Bean counters rule the roost these days. why pay extra for a gear reduction unit if a direct will do the job acceptibly.

Brian Carlton · #14 03-30-2006, 10:42 PM

Chrysler had a gear reduction starter for years. You could tell it was a Chrysler a block away.

Never could understand how the engines actually got running. The cranking speed seemed unbelievably slow...............

gozapper · #15 07-16-2011, 01:22 PM

I have to laugh at all the comments from those that never had the experince of a geared starter!

I have a White 2.45 tractor made in Japan that had two batteries in parralell. It always turned real slow in cold weather. I had to rebuild it several times. The brushes were $12 each from the dealer. My local alternater shop talked me into buying a gear reduction starter that cost me less than what the solenoid on the original starter cost. I could not believe how fast it cranks now. So I do not believe that the manufacters back in the old days always did the best choices on what to use.

Tom