Recommended Modifications/Repairs for 170 Owners

[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]

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

[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!

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.

[blueldr]

Tru-Lock--The ferfect answer to a non problem.

[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.

[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, 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"...

[Daniel96D]

Thanks for the info. I am handing this to my IA for "inspection and compliance" next 100hr or annual whatever comes first. Think I have most of them done already.

[n2582d]

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.)

Special Airworthiness Information Bulletin entitled "Engine Exhaust and Carbon Monoxide Detectors" and the technical report referred to in this SAIB.

[Bruce Fenstermacher]

At the same time you replace the main leaf spring, replace the AN7-20A bolt that attaches the tail wheel to the main spring. This one lasted at least 17 years with an average of 50 hours a year and one landing per hour that's 850 hours/landings. If it breaks on landing it WILL ruin your day.

Photo on 2010-07-01 at 15.57.jpg (77.72 KiB) Viewed 111 times

[gahorn]

At the same time you replace the main leaf spring, replace the AN7-20A bolt that attaches the tail wheel to the main spring. This one lasted at least 17 years with an average of 50 hours a year and one landing per hour that's 850 hours/landings. If it breaks on landing it WILL ruin your day.

Photo on 2010-07-01 at 15.57.jpg

EXTREMELY fortunate you were taxying slowly and on grass. When this breaks on takeoff or (more likely) on landing...the tailwheel flails the rudder to smithereens....adding considerable to the cost and trouble.