The International Cessna^® 170 Association

Could not find this using search, so starting a new thread:
When starting 85C, I notice a lull in the rotation of the prop. I can still hear the starter running but a hesitation in the prop rotation is apparent. I release the pull cable then re-engage and 85C starts fine. I suspect a bad starter clutch (Delco p/n 1971890 from http://www.aerotechlou.com/starter_clutches.shtml). Is this correct or am I missing something?
Also found this on http://www.niagaraairparts.com/
"HAND PULL"
CLUTCH
FOR CONTINENTALS
Delco-Remy 1971890R
$155.00 exchange
Brand New 5 Roller Version Available
I assume the "R" at the end of the part # is rotation direction????
Which company does the membership prefer??I'd rather spend my money with a company that helps the Association!!

Both companies support TIC170A. The "R" stands for "Rebuilt".

But your problem.....

... if the starter is actually "spinning' but not engaging the engine (crankshaft gear) then the shaft (engagement lever) may be mis-adjusted.

The starter should NOT spin until AFTER the gears are fully engaged. This requires that the assembly be properly adjusted. See page 52 of the TCM C-145/O-300 Overhaul Manual, Form X30013. The lever which your pull cable attaches to should have 1/16" clearance before it contacts the pinion/plunger. The Pinion must have 9/16" movement (pushing the plunger into the engine) before the start-switch engages (which rotates the starter.)

If, however, all the above is correct, and the gears are fully engaged ...and the starter motor rotates.... yet the engine does NOT.... then the clutch (rollers) are likely shot and the clutch should be replaced.

It's a simple job, and you can probably do the labor yourself (even if you are not certified to sign it off.)

1. Disconnect your battery. Disconnect the battery cable leading to the switch. Remove the short shoulder-bolt which holds the lever to the side of the starter. (Don't lose this odd bolt.)

2. Remove the 5 fasteners holding the starter and starter adaptor to the engine. (Two saftie-wired bolts and three fiber-lock nuts.)

3. Lift the entire assy clear of the engine.

4. Slide the clutch and pinion clear of the engine.

5. Replace the pinion seal (in the adaptor. Use a new one. Use a new adaptor-to-engine gasket also.)

6. Lightly coat the new pinion shaft with engine oil and reinstall the pinion/clutch.

7. Reverse the process and enjoy. (Do not overtighten the fasteners. Very little stress occurs at this location. Snug is all you need...about 200 in.lbs./25 ft.lbs...less than a spark plug.)

8. Be certain to re-adjust the lever engagement as discussed above with the proper clearances.

I like the Niagra 5-roller clutch. It's probably more robust than the original.

Of course we wouldn't suggest you actually do it if you are not properly rated, just that you could.

If your starter engagement is misadjusted, get it corrected ASAP! The procedure is in the engine overhaul manual. Once upon a time, I had one misadjusted so that the pinion was partially engaged continuously...the reason for my first engine overhaul.

Miles

Did I mention that Niagara will give you a trade-in for your repairable clutch? (Just remember, that if your old clutch-shell is cracked then it's not repairable. The way these clutches work is: As the starter rotates the gear-shaft, rollers roll up an elliptical ramp thereby jamming against the outer shell and locking the shaft/shell together as one, and thereby passing the rotation on to the gear. When the engine starts, it overspeeds the gear and releases the rollers, disengaging the clutch until the pilot can stop the pull-start.) If that shell which contains the rollers splits/cracks due to over-jamming of the rollers, then it is no repairable. Neither is a clutch with damaged gears. Niagara is trustworthy in their assessment of trade ins, so ... give 'em a shot.

Here's their maintenance/installation guide (See the engagement instructions and picture):
http://www.niagaraairparts.com/pull_ica ... 0_2003.pdf

http://www.niagaraairparts.com/ 800-565-4268

I sent an email to Niagara to correct an error on their website regarding window latches. (They incorrectly included the 170's as using the type latch they offer.)

I also told them of our recent discussion regarding starter clutches (I like to keep in touch with vendors who I occasionally ask to support our organization and conventions.) Here's the response from the owner of the company regarding the difference between original clutches/rebuilt clutches, and their own 5-roller clutch:

(George, re: window latch ), I believe you are correct, an error on our part, I suspect. I’ll research this and correct our applicability chart.



As for the clutch, you should be aware that our pull clutches are far superior to any thing else offered anywhere. Our clutch, like the original Delco, is precision assembled and manufactured / ground to actually be able to slip at 1500 / 1800 inch pounds. This avoids the possibility of break up of the pinion gear if and when the engine kicks back on start up. All other “repaired” clutches use a $0.38 pinion gear manufactured for automotive use. We actually spend some $30.00 to manufacture a 2 piece pinion gear with the actual clutch portion being very specially case hardened with a case of 200 thou!

While all other units will drive the clutch rollers into the automotive clutch surface, ours merely slips. Try the test yourself. Torque any one other clutch to 1800 inch pounds OR MORE, it won’t slip! Now turn it backwards and you will feel the indentations left into the clutch surface by the clutch rollers. Over time, the clutch surfaces starts to look like “mashed potatoes” – then it seizes and breaks off in the engine. Try ours – it will just slip without damage! Now, turn ours backwards – no damage.

Although we spent years perfecting our manufacturing procedure; we merely learned to duplicate the original Delco!

I always recommend our “totally brand new” 5 roller clutch as the best buy. Our “R” clutches are just repaired 60 year old units that can suffer a cracked clutch body at any time; after all, it is 60 years old. I have said this to many hundreds of customers who buy our 5 roller clutch – if it cracks the clutch body while I’m still alive and operating Niagara Air Parts, I’ll send you a new one – free!


Ronald Newburg, President

Niagara Air Parts, Inc.
2221 Niagara Falls Blvd
Niagara Falls, New York 14304

Tel: (800)565-4268
Fax: (705)326-8105

I agree with George's comments on the Niagara 5 roller clutch. I replaced two of the older design clutches from Niagara prior to getting one of their 5 roller models and have not had any more problems with it. I must admit I currently have a unit Miles sold me and because it works well, I have not gotten my starter motor back in service. Don't know if Miles' unit had the 5 roller unit or not. Buy Niagara!

170C wrote:...I must admit I currently have a unit Miles sold me and because it works well, I have not gotten my starter motor back in service. Don't know if Miles' unit had the 5 roller unit or not. Buy Niagara!

Frank, the unit I sold you was original equipment as far as I know.

Miles