6.9 - C6 - Flexplate - Ring Gear - aaarrrrrggghhhh

[wildman7798]

So after 5 months of running my truck I got the dreaded starter grind, twice in about 6 starts today. I can't remember the last time it was ever the starter drive that was wore down so I'll figure ring gear as the most likely culprit. My initial search turned up nothing on the chain websites. Called my local CarQuest and they hitting the books for me. Seems like I read here that the IDI's only stop in 3 places so the ring gears must take a beating. What are my options in finding a new one and any input on how fast these go from grinding to not engaging at all would be good.

 

[oregon96psd]

Napa sells the ring gear, could be an option.

 

[bookite03]

I have a whole flexplate...good ring-gear and all! Take a drive down and tow this parts truck home!

 

[vegas39]

I just went through this and is was a nightmare to find the gear! The parts houses don't seem to list the diesel setup, only the thin flex plate for the gassers. After much nonsense, we found a little tiny set of numbers on the gear itself and its an international part number.
I called international and they couldn't tell me how long it would take to get one until I ordered it, jerks.
One of my local Carquest machine shops/parts houses, had the gear up on a shelf, covered in dust from 100 years ago. They charged me 25 bucks for the gear and another 25 to put it on.

 

[vegas39]

On another note, my brother in law has two trucks with major grinding issues and cured the problem on both trucks with the cheap 109 dollar DB gear reduction starter. Don't know whats in the design to stop it from happening but neither of his trucks grind anymore.

 

[wildman7798]

On another note, my brother in law has two trucks with major grinding issues and cured the problem on both trucks with the cheap 109 dollar DB gear reduction starter. Don't know whats in the design to stop it from happening but neither of his trucks grind anymore.

That's all good info. I would invest in the starter first for obvious reasons. I guess it's possible the nose depth or spline cut or diameter could be just enough to provide better engagement. A chance I will be willing to take.

 

[oregon96psd]

http://www.napaonline.com/Catalog/CatalogItemDetail.aspx/Flex-Plate-Gear/_/R-BK_6003112_0359538162

 

[vegas39]

Just remember, if you want to buy a replacement ring, you have to give them the IH part number. At least that's what I went through here.

By the way, Uhaul has the whole flex plate setup for the diesel c6 on ebay for 250 something bucks, brand new.

 

[typ4]

The nippondenso style starter from DB has to be further into the teeth before the contactor spins the motor. This is why they work so much better.

 

[Kevin 007]

The nippondenso style starter from DB has to be further into the teeth before the contactor spins the motor. This is why they work so much better.

So the starter pinion extends further towards the ring gear making "more" contact with the ring gear? Interesting. So this is now the starter I will next purchase if need be.


And as for the engine stopping in the 3 same spots...I also learned this as of recently. I also learned that it could be benificial to rotate the ring gear on the fly wheel to put the worn teeth sections out of the sweet spot where the engine stops and fresh teeth would now be in their place. I will have my transmission out next year and will be pulling the flywheel for this very reason as preventatve maintenace as it is starting to grind on occasion. Strangly, I have never noticed this with the old starter that was on the truck but now I am with this direct drive Bosch rebuilt replacement.

 

[typ4]

The total engagement is the same, it is the initial that has to be in the teeth before the motor gets full power. Too tired to go thru starter operation.

 

[icanfixall]

Heres the deal with the flywheel gear. ONLY THE HEAVY CAST IRON FLEXPLATE CAN USE THE REPLACEABLE GEAR. The thin stamped steel typical flewplates have the gear welded to the wheel. So its best to know what you have before you order parts. Another note is say you have the heavy cast iron plate and want to do away with it you can. Its as easy as changing the flexplate to the thin stamped flexplate type but.. You now need a crank space thats about 1.100 thick. Nobody like international or ford makes those any longer but they are found on idi engines in wrecking yards too. You just have to remove the flywheel cover to see what wheel is on the crank. Now if you really need a spacer I have only one left or Brians Truck Shop (BTS in Leadhill Arkansas) can make one for you too. These are not a wear item so they usually are not replaced. You only need it when you go from heavy to lite flexplate. Most 90 engines and up have the spacer and the stamped steel flexplate as oem stuff. Now for rotating the gear to a sweet spot.. Yes, this is done but make sure you mark the gear and the wheel BEFORE you warm it up to get it off. Make sure you keep the bevel side of the gear facing the starter or you will never get the starter drive to ingage. Its plenty of work getting that deep into this job so make sure you need the gear and want to spin the gear. If you choose to replace the gear then drill a couple of holes in the teeth. Then hit hard with hammer and chisel to crack the gear. Now have the new gear in the oven at no higher than 250 degrees. Hot gloves needed to hurry the hot gear to the wheel. At 250 degrees it will fall onto the wheel easily. Job done. Spray some brakeclean on the crank flange threads to clean it off. Set heavy or lite flexplate on the crank or spacer and use loctite on the bolt threads to seal them from the oily side of the engine oil pan. Those holes are drilled thru the crank and oil will leak out. Torque is 47 lbs. Nice 30 minute job from start to finish...

 

[bookite03]

Bill,
In all seriousness, hopefully your starter ends up being the culprit. Curious to see what you find. I also like what Russ says about the nippondenso. Let the starter really get into the teeth before turning.
If it comes down to needing a Ring-Gear/Flex-plate, just let me know. This one I have here from my 87' is the heavy cast unit like I'm sure your 86' has. The gear is in good shape...just a little bit of wear, but by no means is chewed up. It's not doing me a bit of good now that I switched to the ZF...just something else to trip over in the garage. It's yours free of charge if you need it. We can figure out the logistics later.
Good luck!

 

[idiabuse]

Heres the deal with the flywheel gear. ONLY THE HEAVY CAST IRON FLEXPLATE CAN USE THE REPLACEABLE GEAR. The thin stamped steel typical flewplates have the gear welded to the wheel. So its best to know what you have before you order parts. Another note is say you have the heavy cast iron plate and want to do away with it you can. Its as easy as changing the flexplate to the thin stamped flexplate type but.. You now need a crank space thats about 1.100 thick. Nobody like international or ford makes those any longer but they are found on idi engines in wrecking yards too. You just have to remove the flywheel cover to see what wheel is on the crank. Now if you really need a spacer I have only one left or Brians Truck Shop (BTS in Leadhill Arkansas) can make one for you too. These are not a wear item so they usually are not replaced. You only need it when you go from heavy to lite flexplate. Most 90 engines and up have the spacer and the stamped steel flexplate as oem stuff. Now for rotating the gear to a sweet spot.. Yes, this is done but make sure you mark the gear and the wheel BEFORE you warm it up to get it off. Make sure you keep the bevel side of the gear facing the starter or you will never get the starter drive to ingage. Its plenty of work getting that deep into this job so make sure you need the gear and want to spin the gear. If you choose to replace the gear then drill a couple of holes in the teeth. Then hit hard with hammer and chisel to crack the gear. Now have the new gear in the oven at no higher than 250 degrees. Hot gloves needed to hurry the hot gear to the wheel. At 250 degrees it will fall onto the wheel easily. Job done. Spray some brakeclean on the crank flange threads to clean it off. Set heavy or lite flexplate on the crank or spacer and use loctite on the bolt threads to seal them from the oily side of the engine oil pan. Those holes are drilled thru the crank and oil will leak out. Torque is 47 lbs. Nice 30 minute job from start to finish...

I have the cast iron wheel and I decided to flip the ring gear, still works fine. I use a gear reduction starter also. I was told it wont work. Seems to work just fine...

 

[icanfixall]

Wow... Flipping the gear and taking the chance seems like a huge risk that it wont work but... You tell us it works. So why is the starter side of the gear beveled anyway??? For the time costs and the expense of the gear I'm all in for replacing the gear. Now if money tells you there is no way to replace it then I'm all in for moving the used teeth to another location on the circumference of the wheel. So what made you try flipping the gear knowing there is so much discussion about it not working...