Starter Ring Gear

[Captnmack]

Hey folks...So the starter on a “C” that I GET to fly is not functioning correctly. Looking at just replacing the Bendix but I have a starter on an “F (IO360) that I can rob. Does anyone know if ring gears are the same?

[Yetti]

You need to count teeth on the ring gears.  There are several different teeth available.  I think there are 9 and 10 tooth starter gears.   this page should help in your quest.

https://www.aircraftspruce.com/catalog/eppages/bcstarterlyc.php

[Captnmack]

Ok all, I pulled the 18lb Boat Anchor off the C as well as the one on my dormant F, it’s a Lightweight Sky Tech LS. I was going to just swap out so we could fly but it would have taken some Baffle Mod so I’m just going to wait till Monday and get a Sky Tech locally as opposed to O/H the Prestolight. Missed a great opportunity to fly up to Kansas to visit my youngest at KU....

[J0nathan225]

You can get a credit for "loyalty" if you reach out to skytec and order through them, returning the old starter. 

[Captnmack]

Sky Tech starter saga continues: Ok, picked up a new S/T 149-NL today, went back to plane and installed it only to discover that the Ring Gear/Pinion Gear fitment is too close, the Ring Gear slightly rubs the Starter Pinion. I asked a more experienced A&P who was doing an annual on a “J”. Compared its same 149-NL installation, fitment tolerances, called Hartzell Eng Technology in AL and got some great Tech Asst from Allen. Was told that Superior Ring Gears are slightly thicker and thus that might be the problem and learned that the installed Rind Gear is an “ECI” part. Hmm, maybe that’s it! But alas, after closer inspection I discovered that the Ring Gear was NOT PROPERLY installed when it was installed last, ie..not seated all the way. So now I must tell owner to cough up another $175 for new Ring Gear, pull Prop and do it right this time. This will correct the Starter fitment issue...Argg!

[carusoam]

What keeps you from re-seating the ring that is there?

I’ve not removed the ring gear before...

Best regards,

-a-

[Captnmack]

30 minutes ago, carusoam said:

What keeps you from re-seating the ring that is there?

I’ve not removed the ring gear before...

Best regards,

-a-

Unfortunately once installed usually cannot be adjusted. It’s an interference fit, Ring Gear gets heated, support gets cooled. Once slipped over and cools it’s on there..

[Guest]

8 hours ago, Captnmack said:

Unfortunately once installed usually cannot be adjusted. It’s an interference fit, Ring Gear gets heated, support gets cooled. Once slipped over and cools it’s on there..

I would pack the aluminum support in dry ice and see if it will shrink enough for the ring gear to drop into the correct place, before replacing it.

Clarence

[carusoam]

Seeing if @Captnmack has seen Docs post above...

-a-

[Captnmack]

Ok all. Working on the C has reminded me that perhaps I have forgotten more that I knew! Also the nuances of wrenching on OLD airplanes is a challenge since little is documented. So here goes, follow me: This Engine originally had a “Fine Tooth (122)” pitch Ring Gear and associated Starter. Somewhere along the way the 122 was replaced with a 149 Tooth Ring Gear. The starter that WAS installed was a listed approved starter (MZ 4222), not sure of the Pinion tooth count. NOW, the Ring Gear support that is on there has a Flange/Lip that the Ring Gear rests on. Other supports, like that is on my F does not. At first I ASSUMED that the Ring Gear was not Properly seated or was thicker than normal so I bought a new Ring Gear. It was only after I cut off the still quite useable Ring that I discovered the Support Discrepancy. I called Eileen at Enparts in Dallas (actually Lancaster) and she knew EXACTLY what the issue was, without even seeing the parts! BTW, she is a great source for Engine parts and knowledgeable! So, it was spend more $$ and get a different Support or install the purchased Ring Gear and “adjust” the Starter Pinion Gear teeth as needed. I chose the latter as I could not take the Sky Tech back and NOW it is obvious that I should have chosen that route in the first place! Now for those that don’t know and that was me too, the Ring Gear installation is quite simple; Cut the old Ring Gear off. Clean and inspect the mating surface. Mark Ring Gear for proper teeth orientation (chamfered teeth edge towards starter side). Put Support in Freezer and Bake Ring Gear in your wife’s over at 450’ till hot (not glowing red hot, just hot). Place ice cold Support on solid flat surface and using your wife’s best oven mitts carefully remove from oven and observing CORRECT orientation drop into place. It will be quite loose but after it cools it will be stuck on good....it’s almost all back together but still not flying as I now have an Exhaust Stack issue as I discovered not one but TWO risers that are unairworthy. Now I have to get that repaired/ replaced!!

 

.....

[carusoam]

Great writing, Mack!

Got any pics to go with it?
 

Has the misses figured out the extra stains around the kitchen yet? 

Best regards,

-a-

[RLCarter]

On October 19, 2019 at 9:06 PM, Captnmack said:

Ok all, I pulled the 18lb Boat Anchor off the C as well as the one on my dormant F

My ring gear has a couple of teeth that aren't in the best of shape, great write up on replacing it. But now what can you tell me about the dormant "F"?

[Captnmack]

14 hours ago, RLCarter said:

My ring gear has a couple of teeth that aren't in the best of shape, great write up on replacing it. But now what can you tell me about the dormant "F"?

Well, my F is begging me to resume work on it! 

[Captnmack]

16 hours ago, carusoam said:

Great writing, Mack!

Got any pics to go with it?
 

Has the misses figured out the extra stains around the kitchen yet? 

Best regards,

-a-

I should have photographed each step. I could draw some pics though...