Landing gear strut

[waltermrich]

I know this topic has been discussed before but the landing gear strut is a concern for me, I discovered rust in the lower 6 inches of my gear strut and it looks plentiful tapping on it sounds like the rest of the upper strut but I think it should be addressed, I have seen repairs done on this forum with a sleeve over the strut and that looks like the best option, there is no streamline tubing currently available to just slip over the strut and weld in place, so a larger piece of tubing has to be cut with the rear portion gone so it fits right over the strut on the gear, I have tried it with a sample of streamlined tubing I have, and it fits very well. Anyone who has done this can chime in, This would be considered a major repair or am I mistaken, I know my A and P will be involved, but examples would surely help, Also is there any example of a cable tie put in place to add as a safety in case of failure, I really think this is going to be an issue that many of us will face.

[Scott]

There is a service bulletin that provides instructions on this. I seem to recall that if you can hear debris inside and/or rust comes out when you drill the required drain hole at the trailimg edge, then repairs must be made.

I would replace the strut. The fittings and doublers can likely be salvaged from the old part with careful removal of the weldments. The gear leg is substantial enough that no jigs or anything complicated is needed. If you remove the bolt at the bottom and the clevis and strut remain lined up, fit the new strut in the same way.

A sleave would need to be attached at the bottom (as that's where the corrosion damage will be) which means dealing with the doubler anyway. And the sleave will need to be split as it's unlikely the strut will flex enough to slide it over the end.

Easier and better to replace the whole strut.

S

[Scott]

Here's the doc
MLG bulletin.pdf

Also, I believe it would be possible to drill a small hole at the top... through the bungie end cap, and insert a boroscope to do an internal inspection. This may give enough info to treat the corrosion weld up the hole and done.

S

[waltermrich]

Thank you Scott for your help, I did drill a small hole in the upper area of the strut and ran a bore scope down inside and found an abundance of rust near the bottom, so the need for advice, the service bulletin advises removing the strut and repair replace it, well does that not require cutting existing welds or the upper strut off ? . as you mentioned removing existing welds to get it off sounds like a lot of grinding im pretty good at gas welding 4130 tubing but really do not look forward to it, would a sleeve over the existing strut be adequate especially if it could be welded to the bolt attachment area ? I saw you Taylorcraft in Oshkosh a couple of years ago it was a work of art.

[Scott]

Yes, there's always alot of grinding when doing tubing repairs. The removal process is basically to cut the tube leaving the weldment intact. Then carefully grind away the weldment and the remaining tube until you get back to the original fitting edge or surface.

Usually these gas welds are mostly surface welds ie the original edge can usually be uncovered.

Even doing a sleave, you'll likely still need to de-construct the lower fitting as the only way to make an adaquate joint at the lower end. Hence my conclusion that replacing the whole strut is the way to go.

This way you won't need to find an exact match to the streamlined tubing profile.

S

[waltermrich]

Thank you Scott Im going to have a cup of coffee and think about what Im going to do.

[waltermrich]

I like the Maple Leaf

[waltermrich]

Want to add that the rust in the lower gear strut was unknown to me up till now ,I had cleared the drain hole and all that but untill I looked at it with a bore scope I was not sure, Its alarming and I think it needs to be front and center for Taylorcraft owners, I do not want anyone hurt.

[Scott]

Lps, corrosionX, lo.e oil etc. Injected imto the tube is a easy and effective precaution.
S

[waltermrich]

Thank you Scott will do when finished

[Jim Herpst]

I have been preaching this for a while now.) I had one ideot tell me on the Facebook site they had not heard of any accidents or issues with this area and it was not a problem. .Many folks are selling or purchasing used gear without a clue of how serious this is! Bruce Bixler even wrote in the Taylorcraft owners Club newsletter over Two decades ago that it was becoming an issue.. Guys and Gals this will wipe out your plane! Do NOT ignore this! Scotts idea on an entire new piece of strut make the most sense. The other alternative is to replace the gear with new which is what I did. I used the Univair New gear. The strut is considerably beefier. I had a fellow wanting to purchase my old gear...which when I removed it I heard rust inside when moving it up and down . I would not sell it to him knowing that. My bet is the most are an accident waiting to happen if the plane has spent its lifetime back east. A forever Western plane would be great...in more ways than one in this respect and many many others (aske me how I know doing a restoration on a PA based since new plane! Good news is everything is being replaced with new now new...which brings the $ad news!

[Mark Bowden]

+1 to Scott and Jim. I have to check, but the sleeve repair on mine was done on a form 337 repair. Will report back.

[Hank Jarrett]

Jim, don't toss the gear (I agree I would NOT sell it, but when/if we get a fixture it will certainly be worth rebuilding!). Once we have fixtures for rebuilding the next hurdle will be getting new streamline tube. The steel used around WW-II was a lot more malleable and easier to roll into streamline shape than 4130. I am afraid the reason we are having trouble getting replacement tube is it is cracking along the tight radius at the trailing edge. We may have to open up the shape to closer to an oval than streamline to prevent that and that will cause problem with the FAA accepting it as a substitute unless they have someone who actually understands steel tubing.
It is STILL worth keeping these gear till we can properly repair them!

Hank

[Jim Herpst]

Hank, weeeel I am not one to hold much in my loft at the hangar due to space issues sad to say it is gone. Your point is well taken however. I would have given them to you to hold ....

[waltermrich]

Jim Im glad you are so adamant about this issue, it really is a serious problem as I see it, its an accident waiting to happen just a couple of weeks ago some one with a Taylorcraft on the Taylorcraft Facebook page had a hard landing and broke the gear strut and substantially wrecked his airplane, the lower strut is a perfect pace to collect moisture and rust ,these pieces of metal are 80 to 77 years old, Im in agreement with Hank most of the gear is heavier material but the gear strut is thin walled stuff , a good welder can salvage one, but they all need a Thurow inspection now. I checked into buying 2 new ones but at $2500 each from Univair i could spend it on a really good rebuilt replacement, But if money was no object I would buy new.