The International Cessna^® 170 Association

At 525 hours my starter clutch started occasionally slipping. I noticed it just this week. I'd pull the cable and the prop would turn (with the usual/normal groaning) but the prop would occasionally momentarily pause at the top of compression strokes. It was only barely noticeable, but I decided not to risk a break-down somewhere and went ahead and took care of it last night.
About six months ago I answered an ad from one of our corporate-pilot members who had modified his engine to one of the B & C or SkyTec starters. He wanted to sell his operational original starter and clutch, so I bought them as spares. They bench tested fine, so they reside in a box in the corner of the hangar.
But I don't like re-doing jobs I've already done, so rather than take a chance on a short-term fix, I called Niagra Air Parts (800/565-4268 http:www.niagraairparts.com/ )and ordered their new manufacture clutch.
It comes to $225 plus $150 core on my old clutch.
What surprised me was the price of gaskets and seals. I realize that recent posts discussed the clutch pinion-shaft seal at the autoparts store, but there is another seal on the front of the starter armature that should also be replaced. Additionally, there are two self-lubricated copper/brass bushings/bearings on the engine side of the starter assy., and there's another one at the rear (commutator end) of the armature. The seals and bushings with gaskets come to $69 per starter assy (including new brushes.) I couldn't see myself doing this work on my own without replacing the brushes as well. (They're actually not expensive, only about $4.50 each, times 4.) I replaced them even tho' comparing the new vs the (525 hrs) old, there was only about 1/16" worn from the original brushes. (The new total length of brushes is 3/4" about half of which is useable.)
The reason I was surprised about the recent price increase is because when I called El Reno to order from their 1999 catalog, I found that in only 4 years seals have gone from $4.50 each to $16.50 each (and there are two in the assy.) Bushings/bearings are the same. (No longer only $5, they're now $16.50 also, and there are three of them.)
I started to simply exchange the entire unit, but by the time you send a starter motor out for rebuild, you've got $175 plus shipping, not including the clutch. The whole ball of yarn will end up costing about $500 if you overhaul or exchange yours.
So I ordered El Reno's $69 overhaul kit, and Niagra's new clutch and did the work last night. The only difficult part was removing the old bushings/bearings, but I finally realized they are "split" bushings and are easily removed with needle nose pliers after they're upset with a punch. I used large sockets and a large C-clamp to press the new seals and bushings in. I soaked the new copper/brass bushings in oil and lightly greased the armature shaft ends before reassembly. I also cleaned the armature and field windings with electronics cleaner. (Man, what a lot of brush dust and junk! Pretty surprising considering there was only 525 hours since overhaul on that starter. I was also surprised to find the rear starter bushing/bearing completely dry. I'm glad I did this work.) It took a total of about two hours.
The only really critical item is making certain that the clutch has at least 1/8" clearance from the crankshaft gear, and that it fully engages that gear before the starter motor is energized. It's a very simple process, and the only adjustment mine needed was the pull cable needed to be lengthened/adjusted about 1/8" to allow free-play between the lever and the clutch end. Everything else was a simple remove 5 bolts/nuts, remove the motor and clutch, clean off the old gasket, install the new gasket, and drop-in the new clutch and rebuilt starter motor, tighten the bolts/nuts.
Why didn't I consider the B & C or SkyTec? I didn't want to cut off that pinion shaft inside my engine, and I didn't want to depart from originality. Niagra also claims they've yet to get one of their new 5-roller clutches returned due to wear or failure. We'll see.
Now that I'm back in business with a newly rebuilt starter and new clutch I don't imagine I'll need that spare anymore. I've got another El Reno overhaul kit in hand for it tho'. I'd go ahead and rebuild it too if I didn't think someone else might enjoy doing it.
I actually did enjoy it. Whoo-Boy! Ready for Reklaw!

George, I had wanted to reply to your post on rebuilding the starter sooner, but I have had a heck of a time getting my password straightened out! For reasons unknown all of a sudden it tells me my password is invalid and I got 3-4 new ones and they wouldn't work either. Finally this am I got one to function. Guess they must be case sensitive?

Anyway, back to the starter deal----as you may remember since Labor Day and my annual I had to replace my starter clutch also. When I called Nigara they were out of stock on the old rebuilt units and ended up selling me the "new" 5 roller model at a mere $400. I returned my old unit and of course they didn't advise me about the credit, or lack thereof, until I got my visa statement yesterday. They only allowed me a $75 credit. Guess one doesn't have a lot of comeback as they make the call as to whether or not the old one is rebuildable & if so how much credit to allow. Except for the involved process of cutting off the pinion gear ( there is a web site that explains a couple of options as to how to do so without getting bad stuff in your assy. case & still not have to pull it off) I would op for the new lightweight starter and may do so if (or when) I have to go through this again. In my case I am not attempting to retain orginality, I am going for practicality, but I understand your desire to keep it as orginal as practical. It will be interesting to see how both our experiences with the new 5 roller clutch compare. I average 100 hrs a yr on Ole Pokey (we still have to have a look at why it is pokey!). My last clutch was installed in November, 1999 and only had 232.4 hrs when I replaced it in Sept. (Irealize @ 100 hrs avg/yr that doesn't work out, but think it is close to correct time wise.) That sure isn't much time on a unit. When I ordered the clutch they offered to sell me the gasket set for an add'l. $24 or $25, but I told the order taker I could fabricate the fiber gasket myself for a lot less than $25. At the last minute someone else came online and said it included the fiber gasket AND a couple of other seals & they would throw that in at no add'l cost. Glad they sent them as my AI used all of them. However I suspect they got their $25 + back when they only allowed 50% of the core credit. On the other hand maybe my old clutch was more used up than some in the past. Anyway we can see how our experience goes.

Hope to see you in Reklaw!

The "core" value of your old clutch is borken down (sorry for the pun) thusly: $75 for the pinion gear, and $75 for the drive-gear and clutch body.
Most failures of these clutches are caused by fracturing of the internal clutch body. (Imagine a 4-blade boat propeller. Imagine a steel roller placed on each blade flat. Imagine it it all contained within a metal body and that body contained within a metal canister. When the prop is turned the rollers are forced up the incline of the blade and collide, or jam if you will, against the clutch body. This makes the entire body turn with the propshaft. But after time, the body cracks under the repeated pressure of those rollers colliding with it. That's how this thing works.
If that body is cracked it cannot be reused and it is tossed into the trash along with the small drive gear. Hence: you get only $75 refund for the large pinion gear.
If the body is not cracked you get the full $150 core refund. (Is this a pricing scheme? Perhaps.)
As I said, my clutch had been new, but it had 525 hours on it, which probably is about how many starts it had as well. (You don't say if your failed clutch was a new one or a rebult one when it was installed. The new Niagra, 5-roller clutch is supposedly more durable. We'll see.

<<<"Except for the involved process of cutting off the pinion gear ( there is a web site that explains a couple of options as to how to do so without getting bad stuff in your assy. case & still not have to pull it off) I would op for the new lightweight starter and may do so if (or when) I have to go through this again">>>.


170C,

Can you provide a link to this website on cutting off the pinion gear?

Thanks, Bruce

http://www.skytecair.com/
Tell them I've recommended them if you decide to go with the product.
Their Mr. Chiappe (pronounced Chappie) is an acquaintance. He's agreed to let me bring one of their products to next years convention (Tehachapi) for display and give-away at the awards dinner to one of those that also attends the mx seminar at the convention. Tell him you've heard of their generous donation and want to patronize them (if you decide to go that route.)

Thanks for the link George. I haven't really looked as Skytec starters before, having been thinking about replacing mine with a B&C Specialty unit. The Skytec starter is substantially cheaper than B&C Specialty starters as priced from Aircraft Spruce. The Skytec kit price (model KCST2) to replace our pull starters with push button is $563. B&C is asking for $798 for the starter + $60 for the push button kit. About $300 bucks more. Wonder why B&C thinks his is made from gold?

Bruce

Has anyone used the Lamar starters? I saw them advertized in the Cessna Pilots Association magazine. Said to be 4 pounds lighter than the original unit using different type windings to modernize the starter yet keep it in the original type housing.