170 gear legs - replacement? repair?

[bgammelin]

My gear legs appear to be worn out - landing has always been a bit of a nightmare as they don't track correctly, and I wear out tires at an alarming rate, despite being shimmed previously (but not by the best mechanic). My current mechanic says they could be shimmed better, but since the legs are so worn, it may not solve the tracking and tire wear problems. He said I should think about either replacing them, or having them repaired.

I have three questions. First, what do you all think - do they need to be fixed or can proper shimming make them work despite being so old?

Second, is it possible to replace them with L-19 legs (since there's a pair laying around my mechanic's shop)?

My third question has 3 parts: 1. Does anyone know where to send them to be repaired (I've heard they are straightened and then heat treated)? 2. Does anyone know what that process costs? 3. Any ideas on how long that process takes?

I am grateful for any help or advice you all can provide.

Thanks, Bob

[ak2711c]

Bob, stock 170 gear legs look worn out just by there nature. They are a bit sway backed. I doubt they are worn out, I think more than likely it is just an alignment problem. Find a good knowledgeable mechanic to align it for you first. Unless the gear was damaged at some point and improperly repaired this should work. PPonk is the only company I know of that repairs gear legs. As I recall L-19 gear legs are very different and may not work but I am not sure on that. My personal preference is 180 gear legs. I love mine. Hope this helps. Good luck.
Shawn

[Jr.CubBuilder]

XP mods also repairs them, they also make those titanium legs but those are crazy expensive.

[GAHorn]

Bob, the spring gear legs on 170s don't "wear out". At least not in the traditional sense. There are no moving parts.
If the legs haven't been bent, heated, or wrecked.... If they haven't had their bolt holes worn out from operation with loose bolts.... If the bolt holes have been inspected for cracks at their inner edges with a magnifying glass...
... Then they should be just fine. Don't let someone sell you a "bill of goods" you don't need.
Early legs had a different profile to them than later (post SN 25612) legs. The early legs had an outward sweep to them, while the later legs look "bowlegged".
Some folks feel the early legs have a too "live" spring-rate. I personally don't feel that way, but it may be a personal judgement matter. (Cessna must have agreed, however, as they did change the spring-rate to a stiffer gear at 25612. It might simply be a proficiency issue.) I would not advise anyone to switch early legs for later legs. I believe it's better to simply practice, and get some good instruction if necessary. Any 170 pilot who is current should not have any problems with either type, IMHO.

[wingnut]

XP Mods may have a reconditioned set available for exchange. There # is 1-800-819-9270.

I really wouldn't think you need to replace them, unless you've sprung one. They bounce ALOT before they fail to return. 50+ years of bouncing does have an effect but they should be relatively even and equal in the spring rate. I would find that good mechanic to properly shim the gear springs and axles.

[jrenwick]

... landing has always been a bit of a nightmare as they don't track correctly, and I wear out tires at an alarming rate, despite being shimmed previously (but not by the best mechanic). My current mechanic says they could be shimmed better, but since the legs are so worn, it may not solve the tracking and tire wear problems.....

Any number of people on this forum have described symptoms like that, which were completely cured simply by correcting the toe-in of the main wheels. If you don't understand this process in detail: as a 170 owner, you should. It's described in the 170 book available from this association. Your mechanic should have measured the toe-in and told you what it was, and how he measured it. "Shimmed better" could only mean that the toe-in is incorrect, and that could well explain all of your difficulty.

Best Regards,

John

[4stripes]

My 52 has the stock gear for it's time and always looks bowed on the ground. In flight it looks straight.
My friends 54 model has the higher standing legs. Having flown both aircraft extensively, I prefer the earlier gear. When breaking heavily, the softer gear has less tendency to nose over, while the taller, stiffer gear has a stronger pitch forward moment. Simple physics with the longer arm, more leverage when breaking (trying to nose over).
The softer gear should also provide less stress on the gear boxes on rough terrain.
Cheers Eric

[bgammelin]

Thanks for all the input. I will check the gear and axles for damage and alignment first. I'll let you know what I find and fix, and if it does the trick.
Bob

[mrpibb]

Bob, check the forum, there are many threads on the issue. I myself experienced first hand a out of alignment gear, all I can say is Wahoo.
After aligning the gear my 170 became a pussycat. It took us a good part of the day playing with the shims but it was well worth it at any price.