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case 580ck d188 slow cranking

John580CK

Well-Known Member
Joined
Mar 30, 2021
Messages
55
Location
sw MI
I had no doubt that it did, John.
I just have a natural curiosity about how anything works.
I think perhaps a machinist or some one that knows more than I do, could explain how that substitution can be made without a putting a strain, and accelerated wear of the two gears.
Perhaps it is the huge difference in the OD of them that makes it possible.
not sure about any of that but I took measurements and looked real close,then when I installed it I was smiling like crazy
 

John580CK

Well-Known Member
Joined
Mar 30, 2021
Messages
55
Location
sw MI
I would have been smiling too !
Especially when everybody suspected bad things were ailing your tractor.
I also wonder what the heck was wrong with that rebuilt starter.
me too. I will let you know what they say when I get it back to them. really wish I would have bought the gear reduction 1 first. btw, there are things still ailing my tractor ...lol....pretty sure oil is pissing out at head gasket,good thing it's easy to work on
 

Eric a1cnc

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Joined
Sep 18, 2020
Messages
159
Location
New hampshire
Well,here goes my attempt at a simple explanation.
Gear teeth have a semi curved profile so that as two gears mesh. Called an involute profile. this is so that they can both transmit power and be able to rotate. There are different gear pitches,profiles etc... As long as 2 gears are the same pitch they will mesh. Now, the next important thing is to have the 2 gears center points at the correct distance so the teeth will mesh in the correct position.
https://en.wikipedia.org/wiki/Involute_gear
 

Tinkerer

Senior Member
Joined
May 21, 2009
Messages
9,342
Location
The shore of the illinois river USA
As long as 2 gears are the same pitch they will mesh. Now, the next important thing is to have the 2 gears center points at the correct distance so the teeth will mesh in the correct position.
Thanks for explaining that, Eric.
At last I understand how 9 tooth gear can be substituted for a 10 tooth gear.
Namely the center points have to be altered to make it possible.
I was really curious when I read in the description of the gear reduction starter that the nose section was altered for the 9 tooth.
 

John580CK

Well-Known Member
Joined
Mar 30, 2021
Messages
55
Location
sw MI
I would have been smiling too !
Especially when everybody suspected bad things were ailing your tractor.
I also wonder what the heck was wrong with that rebuilt starter.
I'm thinking there wasn't anything wrong with the rebuilt starter. After addressing the slow crank issue it became very apparent that this engine was weak. Huge amounts of blow by and knocking when hot. tearing into it now and this is what I found.4crank.jpg 4crank.jpg rings.jpg
 

melben

Senior Member
Joined
Jan 14, 2008
Messages
1,026
Location
Williamsport, Pa
Occupation
Retired 50 Yrs with Case dealership
Back to the starters, the Delcos originally installed had a mod program through Case changing tooth number drives, the kit was a new drive and a new casting for the rear of the starter, The new casting had the offset changed to allow proper mesh. I did many of those starter mods in the day. you cannot use the 9 tooth drive without changing the drive housing also if you had the 10 tooth drive. There is simply to much gear diameter difference, As Eric pointed out in his post, the center points have to be correct for the new drive, a 9 tooth starters shaft centerline will be closer to the flywheel than the larger 10 tooth.
 
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Birdseye

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Joined
Sep 26, 2020
Messages
247
Location
Topeka Kansas
I know that you've all heard it before, but I just did it and it made a HUGE difference with cranking and all things electrical on my 580se: Remove and clean back to shiny bare metal the ground strap and everything it connects to including frame, bolts, washers etc.

My machine (580se) was cranking slow (but starting) and lights were not coming on, finally it stopped cranking altogether.

I decided to remove the starter and bench test it, it was fine , lots of pep.
What clued me in was when I checked the 12v connections with a test lamp. The test light glowed bright when connected between the + - posts of the battery but the test light was noticeably dimmer everywhere else. At that point I looked at where the ground strap connected to the bolt thru the frame on the back of the battery box and sure enough i could move it a little. I took everything off the ground path (neg battery cable, bolt/washers, woven strap) and cleaned all including the spot where it touches the frame, back to bare metal with a wire wheel and sandpaper. After reassembly, boom!, it was like a new machine.....fast cranking (outside 30F temp) and all electric components working vigorously (lights, wiper, blower, gauges etc). Since this made such a huge difference and I had overlooked it for so long, I suggest that it cant hurt to spend an hour to dismantle and clean your ground strap and all connections.

The thing is that my machine did crank and start even with this weak ground connection but it was at half the power as with a good connection. I wasn't aware of this in-between, weak-but-functioning state a poor connection can create. I had thought that an electrical connection could only be ON or OFF and so I never suspected the path from the battery to the frame had a problem. Live and learn !
 
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