Supposedly the latest greatest starter...

rockyridgefarm

Well-known Member
Starter was getting pretty shaky on my 4640, so I went to get a new one. This one is tiny. I think he said it had planetary reduction and they have only been out a couple years. It turned the ol 4640 shockingly fast.


mvphoto57338.jpg
 
(quoted from post at 03:08:32 06/26/20) Starter was getting pretty shaky on my 4640, so I went to get a new one. This one is tiny. I think he said it had planetary reduction and they have only been out a couple years. It turned the ol 4640 shockingly fast.


I thought the same thing about them gear reduction starters. Them little motors spin like heck giving you the impression that the engine is cranking like hell. In reality the RPM of that little motor is greatly reduced by the reduction gears. By the time the power hits the flywheel you are not turning the engine over any faster.

Review the link below from my testing with these gear reduction starters.
Currently I have a standard in line Denso starter off of a 40 series and an electric destroke. If you want it to spin faster the electric destroke is the answer. It is cheaper than batteries and starters in the long run.

https://forums.yesterdaystractors.com/viewtopic.php?t=1378360&highlight=starter
 
This is a gear reduction starter on my 4430


mvphoto57389.jpg


The new starter I just got is supposed to be the latest greatest. We will see.
 
That's an OSGR Starter (Out Side Gear Reduction).

What both you and I used were the Planetary Gear Reduction.

Both accomplish the same thing, they take the high RPM and low torque of that tiny motor and reduces it to create enough power to spin the engine over. This is no different than the transmission in a tractor. If you have enough gear reduction a smaller engine can pull the same load.

The advantages of a gear reduction starter (more so the Planetary) is that they are physically smaller to they can put them in a tighter place to achieve the required output power to spin the engine over.

I am curious to know if you put a photo tachometer on the front engine pulley to monitor the actual cranking RPM of the engine. I suspect that it will be no better than the standard starter.
 
That is an interesting observation, gear reduction starters "appear" to crank faster, but may just be the motor sound. My MH44 with 6V starter on 12V cranked 300 RPM, with 12V reduction cranked 200 RPM. This starter is much easier on the ring gear, but so would 6V.
 
(quoted from post at 08:58:05 06/26/20) That's an OSGR Starter (Out Side Gear Reduction).

What both you and I used were the Planetary Gear Reduction.

Both accomplish the same thing, they take the high RPM and low torque of that tiny motor and reduces it to create enough power to spin the engine over. This is no different than the transmission in a tractor. If you have enough gear reduction a smaller engine can pull the same load.

The advantages of a gear reduction starter (more so the Planetary) is that they are physically smaller to they can put them in a tighter place to achieve the required output power to spin the engine over.

I am curious to know if you put a photo tachometer on the front engine pulley to monitor the actual cranking RPM of the engine. I suspect that it will be no better than the standard starter.

Just for the record, "OSGR" means OFFSET gear reduction.

"Offset Gear Reduction Starter (OSGR)
This type of starter uses an internal gear set used to increase torque. The internal gear sets are offset which means the drive gear and motor rotate on different axes."

"Planetary Gear Reduction Starter (PGR)
This type of starter is similar to the Offset Gear Reduction, however the gear sets are not offset which means the drive gear and motor rotate on the same axis."

Source: https://densoautoparts.com/glossary-of-terms-starter-alternator
 
Your dead wrong the gear reduction spins the engine faster
may have get a tachometer to prove it I guess .
 
(quoted from post at 08:40:21 06/27/20) Your dead wrong the gear reduction spins the engine faster
may have get a tachometer to prove it I guess .


Please do and get a tachometer. With out hard facts your just guessing. As the link that I shared showed the numbers that i came up with when I did my testing.
 

Thanks for correcting my terminally, it has been a couple of years since I researched the starters.

The key phrase there would be:
[b:26ff403fe4]This type of starter uses an internal gear set used to increase torque.[/b:26ff403fe4]

Increase torque as that tiny motor does not have enough power to turn the engine over. When you increase the torque using gear reduction, you loose outputted RPM's. The theory behind a gear reduction starter is no different than any of the tractors that people put them in. The wheels don't turn 2000 RPM's, but the engine sure does!
 
FWIW
Converted our 4010 diesel from 24 to 12 volt couple years ago

The Sales spec describe it as : Starter - Iskra PLGR (18483), Iskra Style - Planetary Gear Reduction

Has an extra threaded hole near bottom mounting bolt to connect battery ground cable.
cvphoto48588.jpg
 
(quoted from post at 04:47:57 06/27/20)
(quoted from post at 08:40:21 06/27/20) Your dead wrong the gear reduction spins the engine faster
may have get a tachometer to prove it I guess .


Please do and get a tachometer. With out hard facts your just guessing. As the link that I shared showed the numbers that i came up with when I did my testing.

I do not know. Maybe perception is reality on this one. This is why I do not put much stock in testimonials. I WANT to believe the money I spent was worth it, so I give it a good review. I like it better than the gear reduction starter on my 4430. It looks better and sounds better.

I have three different style of starters now. This one on a 4640, and original on a 4840, and a gear reduction on a 4430. The two 40 series have been good starters since I have owned them. The 4430, not as much.
 
They draw less amps to make the same torque
to the ring gear. And are usually a lot
lighter. After picking one up one-handed
for an n14, grabbing the old direct drive
one-handed would have been disastrous had I
not got out from under it first.
 
My brother smoked the starter for in his 4430. Ran to the Deere dealer and paid through the nose for a brand new starter. Not a remain as thats what was on the shelf. Cranked about the same speed as the factory one 200rpm give or take for temp. I bought a cheap OSGR off eBay, highest kW I could find and only $135, put it in and gained around 105 cranking rpm. Yes, they sound faster because they are, at least based on my measurement with a non contact tachometer. With the factory starter the tach in the tractor wouldnt move, with the OSGR it actually registers rpm.

You also need to pay attention to what starter you buy and the rating. I have a Ford with the 6.0 diesel. The original starter is a 2kW OSGR. If you put the 2kW OSGR off a 6.4 diesel you will gain 50-75 rpm cranking speed and if you the 2kW OSGR off a 6.7 diesel you will gain 100-125. This has been documented many many times and there are YouTube videos about it. If you take them apart they look identical, Im not sure what makes them faster but in does make a difference.
 

A fairer comparison would be a new gear reduction vs a new direct drive . Instead of comparing the new gear reduction to the worn out direct drive .
Gear Reduction starters also have power ratings . Dont
Expect a 3Kw gear reduction to our crank a 5 Kw direct drive .
For those who really want to know . There are power vs rpm graphs on the AC Delco starter site .
It is eye opening to observe the Hear reduction MT28,MT29, MT35, MT38, MT39 Vs the Direct drive MT37,MT41, MT42 and MT50.
The MT39 gear reduction has power similar to the MT42 direct
Drive .
If installing a gear reduction on a six cylinder Waterloo . Why bother with the 4Kw Denso when there is a 5Kw Denso ? Nobody ever installed too large of a starter on a diesel .
One of these days the plan is to find out if a MT39 will bolt into a
 

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