Recommended Modifications/Repairs for 170 Owners

How to keep the Cessna 170 flying and airworthy.

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GAHorn
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Recommended Modifications/Repairs for 170 Owners

Post by GAHorn »

It's been the suggestion of AR (Arkie) Dave and N9149A (aka "Pedal-Toy") :wink: that a new thread be started to address mods, etc. that a new owner might put on his list of "Important Considerations"...a sort of "to do" list of mods/work that are considered important/preferred by those of us who've already been involved with the airplane.
Keep in mind that this message thread is only a list and not intended to be an actual discussion-thread. If anyone feels that items mentioned here deserve special treatment or lengthy discussions (pros/cons/etc.) then please feel free to begin a new thread with it's own subject line regarding that item. Pros/Cons should probably be started in The Pilot Lounge and details of performance or "how to's" should probably be placed in The Hangar.
If anyone has their own ideas/favorites...feel free to add them here along with a short description of why the mod/work is considered of import.

Some of the mods/work I've thought might start this list off are:

1. Convert to either the Solid Ski Axle (PN 0541124-1) (or the H.D. steel axles with the proper documentation) to avoid breakage of the standard hollow aluminum axles. Inspect the axle attach bolt holes for cracks with a magnifying glass/dye penetrant. Radius the holes. Check for AN6 lower bolt holes and install/radius them if not present. AN bolts are OK, NAS are stronger.
2. Disconnect the parking brake and completely remove the parking brake hardware from the top of the master cylinders, to avoid accidental setting of a brake in strong crosswinds (hits the firewall blanket and inadvertently sets the parking brake) which results in blown tires, runway departures, and ground loops on landing. (The park brake control is a Bowden cable, similar to a lawn-mower throttle cable, consisting of a solid wire core wrapped by a spiral wire sheath. Push the knob IN, and bend the solid wire core over the end of the outer sheath. This will prevent anyone in the future from being able to pull that knob believing they've set a parking brake, yet will allow your panel to retain it's original look.)
3. P-ponk landing gear bulkhead beef-up. (OK, I know. some mechanics claim this causes even more damage if the airplane is truly wrecked. But my position is that if you can show me two identical wrecks, one without and one with the P-ponk kit, then we can make a more accurate assessment. ANY airplane can be damaged beyond economical repair if you drive it into the ground hard enough. I just want the added strength of the P-ponk so that a simple bolt failure doesn't total my airplane!)
4. At least ONE vented fuel cap (on the right wing filler.)
5. Upgrade to modern Tefzel electrical wiring.
6. Inspect the wing attach blocks inside the wing spar carry-through for corrosion.
7. Inspect the rudder cables where they pass through the rear bulkheads in the tailcone. You'll have to either pull them out for inspection, or add an inspection hole to the aircraft per the structural repair guidelines.
8. Replace your tailwheel main leaf spring every 500 hours. Remove the sharp lower/trailing edge of the leaf spring just above it in order to avoid it creating a stress-riser on the mainspring.
9. Install B.A.S. tailpull handles (to avoid sideways pressures on the vertical stab. fairing when ground handling. Pushing/Pulling on that vert. stab. fairing cracks the bracket in it's leading edge.
10. Avoid use of rudder locks that hold the upper counter-balance area of the rudder, as a strong wind will break your upper rudder internal rib. .(Also avoid blocking the rudder at it's bell-crank stops as it overstresses them.) Use a rudder lock that holds the rudder at it's trailing edge such as rope/bungee types.
11. Install shoulder harnesses. (Remember that shoulder harnesses do not have to be PMA'd, STC'd, or TSO'd for installation in a 170B, because you don't have to cut/weld/alter the airframe...the B already has the #10 rivnut installed in it's rear spar....so you can use experimental, automobile, non-certified cheapies if you wish...just install some! The authority for this statement is FAA Policy Statement Number ACE–00–23.561–01)
12. Install Cleveland brake conversion to avoid parts availability and locked-up brake problems with Goodyears.
13. Install a carbon monoxide detector. The paper stick-ons are neither durable nor sensitive enough for serious use. The best ones are specifically designed for aircraft use and are permanently mounted. See Aircraft Spruce, Chief, etc. for aircraft C.O. Detectors. (Residential/Home types are rarely sensitive enough for aircraft use, although Canadian types are generally more sensitive than those intended for the U.S. market. U.S. rules are designed to prevent false alarms, which may be too insensitive for value in an aircraft.)
14. Install an L19 tailwheel tie-down eyebolt (PN 0642105) in lieu of the AN7-22A bolt that holds your tailwheel assy to the main leafspring.

Addendum: Member AR Dave suggested:
15. Consider an additional seat stop to prevent inadvertent release of the seat and/or undesired travel of the seat in flight. (I personally didn't consider such items which should be covered by regular mx or AD notes to merit inclusion in this list (such as seat track/seat latching condition), but if I understand Dave's concern correctly, the addt'l seat stop is held by some to be an important mod. due to safety concerns surrounding the Cessna seat latching system. I once had an aftermarket seat stop that I removed because I found it an unwanted complication which prevented me sliding my seat aft for exit purposes. I found it difficult and time consuming to reach down/around the lower seat tracks to loosen it sufficiently to exit the aircraft. I'd personally rather keep my tracks/seats in proper safe working order, and still be enabled to get out in a hurry if I desired.) But I agree with Dave that it's a consideration all might with to contemplate.

16. Replace the engine-to-firewall COPPER oil-pressure sense-line with a rubber line. This is an age-old problem (copper oil lines) that date all the way back to Lindbergh and Rickenbacker. Copper work-hardens from vibration and bending and it’s only a matter of time before it fractures in-flight and your oil dumps overboard and the engine seizes if you don’t notice the loss of oil pressure. At the very least, replace it with what Cessna eventually did...aluminum on C-150s. Still-later Cessna, Beech, and others graduated to flexible hydraulic-type lines. (Thx to Member Richard Wilkening for the reminder)

These are just a few recommendations that come to mind, and are my own opinions. Many other participants in this forum have their own favorites/opinion.
Last edited by GAHorn on Thu Feb 03, 2005 6:34 pm, edited 7 times in total.
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
Rob Tasker
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Re: Recommended Modifications/Repairs for 170 Owners

Post by Rob Tasker »

Cessna is giving away a new secondary seat stop, labor included. Yes thats right, FREE.
Check it out with your local Cessna Service Center.
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blueldr
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Re: Recommended Modifications/Repairs for 170 Owners

Post by blueldr »

Chris Christensen,
You mentioned that a pilot owner, properly rated in his airplane, would be always be considered the PIC even while undergoing instruction from a CFi.
How about the case where the owner pilot is "rated" in the airplane but lacks an instrument rating. He has contracted a CFII to teach him to fly instruments in his airplane. During the course of instrument flight instruction they file an instrument flight plan and the instructor proceeds to teach the "student" approaches to the local airport in IMC. Who is the PIC?
BL
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jrenwick
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Re: Recommended Modifications/Repairs for 170 Owners

Post by jrenwick »

Also, if you are getting a flight review because you haven't had one in the last 24 months, you are not authorized to act as PIC. In that case, the instructor is PIC.

John
socata1
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Re: Recommended Modifications/Repairs for 170 Owners

Post by socata1 »

About item # 15, seat stops.
Cessna has a current service kit that is no-charge or covered under warranty thru the end of September 2008 Only the Pilot seat is no-charge to co-pilot is at charge . The service kit part number is SK210-174 or SK210-174A for the pilot seat and SK210-175 for the co-pilot, The 174A just covers more serial numbers but is the same kit. Price on the SK210-175 is 168.00 The kit consistest of a Inertia reel and a bunch of hardware.
The above kits fit all 170'S 1948 thru 1956
We carry these instock, give me a call if your local Cessna Dealer cant help you.

P.S. The kit must be installed by a service center to be covered under warranty.
Good luck
Thanks
Dave
phone 503-666-3838
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flat country pilot
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Re: Recommended Modifications/Repairs for 170 Owners

Post by flat country pilot »

Where can I find Item #14?

14. Install an L19 tailwheel tie-down eyebolt (PN 0642105) in lieu of the AN7-22A bolt that holds your tailwheel assy to the main leafspring.

Does anyone have a picture of it on your tailwheel and is it strong enough for towing the 170 into a hangar?

Bill
Flat Country Pilot
Farm Field PVT
54 C170B
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Bruce Fenstermacher
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Re: Recommended Modifications/Repairs for 170 Owners

Post by Bruce Fenstermacher »

flat country pilot wrote:Where can I find Item #14?

14. Install an L19 tailwheel tie-down eyebolt (PN 0642105) in lieu of the AN7-22A bolt that holds your tailwheel assy to the main leafspring.

Does anyone have a picture of it on your tailwheel and is it strong enough for towing the 170 into a hangar?

Bill
Don't have a picture but think of the stock bolt with about a 1 1/4" inside dia. ring welded to the head. I have one and I would tow my plane with it with out a swcond thought. Not sure who the current supplier is but sure George will chime in with that info.
CAUTION - My forum posts may be worth what you paid for them!

Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
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GAHorn
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Re: Recommended Modifications/Repairs for 170 Owners

Post by GAHorn »

Air Repair, Inc., PN 0642105 eye bolt. (662) 846-0228
PN 0642105.jpg
PN 0642105.jpg (45.81 KiB) Viewed 15671 times
Most folks install them eye - UP , rather than down.


(Mod note- Picture is not the one George originally posted as it's link was broken. This picture of PN 0642105 was posted elsewhere by Gary Friesen)
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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flat country pilot
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Re: Recommended Modifications/Repairs for 170 Owners

Post by flat country pilot »

Thank you George, and Bruce.

Ordered one today, $21.
Not the most expensive bolt I have purchased, but I'm sure its close.

Bill
Flat Country Pilot
Farm Field PVT
54 C170B
flier
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Re: Recommended Modifications/Repairs for 170 Owners

Post by flier »

rudder locks
I built one using 3/4" pvc and foam pipe rap cut 2 lenghts of pvc so that they will fit around entire rudder glue 4 90 degree elbows on the ends of the 2 lenghts of pvc. glue the two halves together and rap with foam the whole assembly should slide over the rudder to keep it from slamming against the stops in high winds
drewolfa
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Re: Recommended Modifications/Repairs for 170 Owners

Post by drewolfa »

Below is a link for True Lock axle nut replacements featuring our '55 170B...
You'll have to copy and paste to your browsre window because I can't figure out how to post a link.

http://www.youtube.com/watch?v=XWGhjDeKGjM
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GAHorn
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Re: Recommended Modifications/Repairs for 170 Owners

Post by GAHorn »

At the risk of coming across (again) as the bad-guy, (but since I started this thread and since it is entitled "recommended" modificatons/repairs)... I feel I must say that the Tru-Lock axle modification is not one I recommend.

While it's developer is doubtless a fine fellow, and while those who've adopted the system are doubtlessly proud of it.... It is nonetheless an elegant and sophisticated, relatively-expensive solution to a non-existant problem.

There is nothing simpler (or less expensive) than a cotter pin thru a nut. The fact that some folks seem to have difficulty inserting the pin....is probably because no one has taught them the easy way to do it. (Bend the cotter into a 45-degree angle about 1/3-rd from the split-end and insert it up to the bend,... then straighten the pin...and finish inserting it.)

If you are someone who has difficulty finding a hole in an axle and twisting the nut onto the axle to align the hole in the nut with the hole in the axle...then any more sophisticated system of retaining the wheel on the axle is likely to give you trouble also (and will require a tool you probably don't own .... snap-ring pliers....which you must keep aboard/handy in case you need them.)

First, To find the hole... take note of it's position on the axle prior to installing the nut, and then install the nut, twisting by hand until the hole in the nut is at the same position as the hole in the axle. If you can do that by twisting firmly by hand...then you are ready to insert the cotter.
If the nut becomes too tight to twist by hand prior to the hole in the nut aligning with the hole in the axle... that's fine! Now use your large pliers or wrench to further tighten the nut until the hole aligns. Congratulations! You have just found a simple way to pre-load the tension on your wheel bearings without tightening them excessively. (Bearing pre-load is a desireable condition. It is not harmful. It is beneficial. It prevents bearings from chatter due to excessive end-play. As long as you don't tighten more than one nut-hole-position then the bearings will not be harmed whatsoever. Virtually ALL taper-bearings require preload for proper function.)
PS- You can insert the tip of your cotter into the hole in the nut prior to the final-tighten...and the cotter will fall into the hole in the axle as the nut is perfectly aligned..which helped you perfectly align it! :wink:

Another good feature of the original system: You won't likely find yourself in Baja Calif., TimBukTu, or NeverLand, trying to find the proper sized snap-ring because you broke/stretched/lost yours. You can find cotter pins virtually anywhere, or you can substitute a piece of safety wire, clothes-hangar, nail, etc. until you get home.

Meanwhile you've saved a couple hundred dollars needlessly modifying your airplane to a proprietary system relatively unknown except to a few people.

One more thing: The Tru-Lock system will not work on aircraft that utilize wheel pants. I thought it dis-ingenuous to produce a video using a wheel-pant nut in an effort to demonstrate "difficulty" in inserting a cotter pin.... in support of a product which cannot use wheelpants. :?

Plain castellated nuts are idiotically simple to see the axle-hole alignment...but that would not have been sufficiently confusing to the prospective customer, I suppose. :?
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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blueldr
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Re: Recommended Modifications/Repairs for 170 Owners

Post by blueldr »

Tru-Lock--The ferfect answer to a non problem.
BL
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Re: Recommended Modifications/Repairs for 170 Owners

Post by hilltop170 »

My ski axles insert into the hollow wheel axles so a cotter pin can't be used. A welding rod bent in the shape of a "D" with a gap in the straight side works great. I use them year-round. Cost, nothing.
Richard Pulley
2014-2016 TIC170A Past President
1951 170A, N1715D, s/n 20158, O-300D
2023 Best Original 170A at Sault Ste. Marie
Owned from 1973 to 1984.
Bought again in 2006 after 22 years.
It's not for sale!
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Abe
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Re: Recommended Modifications/Repairs for 170 Owners

Post by Abe »

George,
(Bend the cotter into a 45-degree angle about 1/3-rd from the split-end and insert it up to the bend,... then straighten the pin...and finish inserting it.)
This is the first time I have "read" how to properly secure a cotter pin...However, :oops: I'm a "visual" type of learner and was wondering if you could put a more "visual" description of this process...as the above description hasn't computed into the finished product in my "computer"...
Bill
'52 170B
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