tailwheel

[dpowell]

Hello all,

I did buy the '48 170 and am in the process of joining the assoc. I shall have a long list of gigs to ask about. The O300d stc was in fact in the logs however it was not done properly as far as I can tell( still has pull starter etc). My first question is this, the scott 3224 tail wheel will not break free while taxiing, even standing on the brake with lots of throttle. Previous owner said somthing about his mech had tightened up "something". I have taken it apart and it appears that the rudder does not have enough travel to cause the horn to turn far enough to allow the pawl to cause the spring to slide past the detents. (WHEW that was a mouthful). Does this pawl come in a larger size(more circumference)? ,or, is there some other problem. There are three springs installed in the mechanism. Thanks for any help.

[c170b53]

Great to hear from a new 170 owner, thanks for contemplating joining the club and if I may quote someone else (possibly Bruce) " Oh boy fresh meat". There's a ton of info at your fingertips simply become familiar with using the search engine to get an overview of your problem. Then possibly provide year, s/n, IPC reference and also a pic never hurts. Try this thread for the parts break down:http://www.cessna170.org/forums/viewtop ... deo#p60874. The previous owner may have item"s (bolt and nut) #9 and #29 from the tail wheel parts tightened. There's an adjustment to make there with regard to how tight that assembly should be, sometimes its adjusted too tight to try to eliminate a wear problem. This thread will advise on tightening the assy. http://www.cessna170.org/forums/viewtop ... ent#p53020. There's a ton of talent here so unload. You now have an idea as to what your looking at, now you'll need some oversight, so establish a work arrangement with a licensed mech and get her ready for Longmont. Colorado.

[GAHorn]

The pawl and detents are standardized and only one size. The springs you mention are the compression springs (?) and 3 are the correct number...but there is also a flat "U" shaped spring which pre-loads the pawl and if it fractures will result in a non-swivelling tailwheel.

[dpowell]

Thanks for the encouraging words. I will explore those links shortly and hope to get this issue behind me. The flat steel spring appears to be new. I'll let you know how it goes. Thanks again.

[Bruce Fenstermacher]

Pictures of your chain and spring control set up from your rudder to the tailwheel can save a thousand words. The stock 170 setup should be barely enough travel to disengage the flat u shaped steel spring paw in the tailwheel.

[jrenwick]

Yes, a photo would help. I've seen a tailwheel fail to swivel because compression-type springs were used between the rudder and tail wheel. That's a no-no for 170s.

I'm talking about this type of spring:

[GAHorn]

Oh yes...one other reason a tailwheel will not swivel... is due to improper/extreme forward/positive caster angle.

[dpowell]

Thanks again guys. I'll get a pic and try to post it. The springs look exactly like the ones in your pic.

[GAHorn]

Thanks again guys. I'll get a pic and try to post it. The springs look exactly like the ones in your pic.

Get rid of them...they will damage your airplane. Compression springs become "solid" when fully compressed and additional pull on the rudder cables then have no "give"...they can rip pulleys from bulkheads and bend metal. Your airplane should have "tension" springs.

[jrenwick]

*Erroneous advice deleted*

[Bruce Fenstermacher]

tensionspringkit.jpg (13.74 KiB) Viewed 17648 times

The picture on the right is of the lighter Scott spring #2151 which is smaller in diameter and thinner but longer and is the WRONG spring for our 170 unless you are using the original Scott 3-24B tailwheel.

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Tail%20wheel%20steering%20spring%20for%20170.jpg (43.77 KiB) Viewed 17648 times

Above is a picture of the Scott #3239 spring you should have. This particular example is used and the ends might be tweeked a bit making it about 4.5 inches outside end to outside end. Spruce and UNIVAIR have these springs but you must ask for them by part number. For some reason they no longer picture them in their catologs.

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comprspringkit.jpg (14.53 KiB) Viewed 17648 times

Do Not under any circumstance use Maule compression springs pictured on the right. They may be good for a Maule but they likely will lead to damage of bulkheads in our 170 aircraft.

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Here is a PDF I found somewhere, probably the Cessna 140 site by a guy named Neil that has good pictures of all the steering springs and drawings with dimensions.

tailwheel_steering_springs.pdf

(288.35 KiB) Downloaded 779 times

Hope this gets everyone on the same sheet of music.

[dpowell]

I tried to read the thread on tightening the tail wheel assembly and it said that I was not authorized to read the thread. Can someone tell me how to get to the info in that thread??

[Bruce Fenstermacher]

Why yes we can answer that question. That thread is in the MX library only available to TIC170A members. I recall you said you were in the process of joining the TIC170A. If you haven't yet joined by phone the most popular way to join is to click this link Join TIC170A or renew membership or the one like it found at the top of every page. Fill out the form and use Paypal to join. We will then get you set up ASAP.

[dpowell]

Finally got back into the air today with new tailwheel springs (tension) and 36V now handles just like it should. Wheel breaks free and I can now do a point turn. Thanks for the help .

[Fearless Tower]

Can someone please confirm the correct Part number that Spruce has for the Tension Springs???

I just got the final invoice for the annual-turned-restoration of my '48, and as I was going through it, I found the Compression Springs listed above on the bill (I had my A&P install a brand new Alaskan Bushweel 3200). The part number on the invoice matches the photo of the compression spings exactly.

I haven't seen the plane yet (I'm supposed to go up to CNO to test fly it tomorrow), but am very concerned and want to make sure I have the right springs.

So far, the closest thing I have found was from Alaskan Bushwheel - 3239 - Heavy Duty Tension Spring Kit which runs for $54. How do I order just the springs?