Outboard landing gear bracket
Moderators: GAHorn, Karl Towle, Bruce Fenstermacher
Outboard landing gear bracket
During the annual inspection on my "53 C170B, my mechanic found intergranular corrosion in the left side, outboard landing gear bracket. (page 40 diagram #47 part number 0713495 of the C170B parts catalog). The corrosion and crack that developed from it is significant enough to warrant replacement. I have already ordered a replacement part from P-Ponk, but I am wondering if anyone has made this repair, and, are there any tips or deep dark secrets, to make this repair as efficiently as possible. I searched the forums and did find some discussion about this issue, but nothing concerning the actual repair process. Any advice would be appreciated. By the way I just paid for my TIC170A membership for a couple of years since P-Ponk gives an association discount! Thanks again TIC170A!
Steve McGreevy
N8293A '53 C170B
N8293A '53 C170B
- Bruce Fenstermacher
- Posts: 10318
- Joined: Tue Apr 23, 2002 11:24 am
Re: Outboard landing gear bracket
And besides you have to be a member to be on the board making big bucks.N8293A wrote: By the way I just paid for my TIC170A membership for a couple of years since P-Ponk gives an association discount! Thanks again TIC170A!
CAUTION - My forum posts may be worth what you paid for them!
Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
Re: Outboard landing gear bracket
Sorry to hear that Steve, your machine is a beauty
Jim McIntosh..
1953 C170B S/N 25656
02 K1200RS
1953 C170B S/N 25656
02 K1200RS
Re: Outboard landing gear bracket
Thanks Jim and Bruce I only hope there is someone who has made this repair and has some words of wisdom to pass along. I really don't want my maintenance folks learning as they go! Here is a picture of what got us digging deeper. This is looking at the outboard face of the bracket. The really telling view is after they removed the gear leg and seeing the slot the leg slides into. The top of the lower edge of the slot was split open. More to come.
Steve McGreevy
N8293A '53 C170B
N8293A '53 C170B
Re: Outboard landing gear bracket
Generally I believe that's what I've seen happen when iron oxide is mechanically worked into an aluminum alloy, dissimilar metal corrosion sets up corrosion which runs through the grain structure of the extrusion and eventually the part fails. Likely a good reason to make sure that the wedges are checked tight and preventing any relative movement between the parts during your annual. As well all these parts should have some surface protection.
Steve it would be interesting to know the condition your gear leg's surfaces where the gear makes contact through the fitting/wedges and whether there was relative movement between in the parts.
Steve it would be interesting to know the condition your gear leg's surfaces where the gear makes contact through the fitting/wedges and whether there was relative movement between in the parts.
Jim McIntosh..
1953 C170B S/N 25656
02 K1200RS
1953 C170B S/N 25656
02 K1200RS
-
- Posts: 526
- Joined: Thu Dec 02, 2004 1:52 am
Re: Outboard landing gear bracket
This link Might help you visualize the issue.N8293A wrote:During the annual inspection on my "53 C170B, my mechanic found intergranular corrosion in the left side, outboard landing gear bracket. (page 40 diagram #47 part number 0713495 of the C170B parts catalog). The corrosion and crack that developed from it is significant enough to warrant replacement. I have already ordered a replacement part from P-Ponk, but I am wondering if anyone has made this repair, and, are there any tips or deep dark secrets, to make this repair as efficiently as possible. I searched the forums and did find some discussion about this issue, but nothing concerning the actual repair process. Any advice would be appreciated. By the way I just paid for my TIC170A membership for a couple of years since P-Ponk gives an association discount! Thanks again TIC170A!
http://www.cessna170.org/forums/viewtop ... ox#p118176.
In any case you will need to remove (drill off) the upper cover or lower skin over the gear box to gain access. P-Ponk has a little video on his there web sight of how the P-Ponk gear beef up kit works that shows the arrangement of all of the parts. The are a number of issues to be addressed with riveting parts that have to be installed. In any case I would Give Steve Knopp a call at P-ponk and ask to discuss it with him as he has done this a few times.
Regards,
Jim
A&P, IA, New owner C170A N1208D, Have rebuilt some 50 aircraft. So many airplanes, So little time!
Re: Outboard landing gear bracket
Thanks Jim and Jim for the advice. We will definately contact Steve at P-Ponk for some tips. Jim I will try to take some pix as we go along, including the area at the top of the gear leg and the wedges. I believe you are right Jim, there is/was some movement in that area that set about this process.
Steve McGreevy
N8293A '53 C170B
N8293A '53 C170B
- 48RagwingPilot
- Posts: 144
- Joined: Wed Dec 12, 2012 3:28 am
Re: Outboard landing gear bracket
IIRC, the outer landing gear bracket is riveted to the cabin floor and belly skin and bolted to the two bulkheads immediately fore and aft. Several years ago I converted a C182 to a C180 and remember having to remove the belly skin and peel up the cabin floor to gain access. I don't know you'll have to do all that, but suspect you may. The good news is that it's mostly grunt work you can do yourself under supervision. If you know or can learn how to rivet, you'll be miles ahead money-wise. Good luck!
Dave
Dave
Re: Outboard landing gear bracket
Well the repair is well underway. Thanks to those who chimed in. Most importantly thanks to P-Ponk for supporting our aircraft, and our association. The replacement bracket is of high quality and the advice from P-Ponk has helped this process go relatively smoothly. I tried to upload some photos but they are all too large. Here is a link to photobucket where photos of the parts can be viewed.
http://s328.photobucket.com/user/smcgre ... .jpeg.html
http://s328.photobucket.com/user/smcgre ... .jpeg.html
Steve McGreevy
N8293A '53 C170B
N8293A '53 C170B
- 48RagwingPilot
- Posts: 144
- Joined: Wed Dec 12, 2012 3:28 am
Re: Outboard landing gear bracket
Wow, you're making great progress!!
Re: Outboard landing gear bracket
Dave,
Thanks for the encouragement. Although I can't take much credit for the repair. Other than cheerleading and taking photos, I am leaving this repair to the pros. I know my limitations and I have a great shop here at the airport where we live. So this is in their hands.
Thanks for the encouragement. Although I can't take much credit for the repair. Other than cheerleading and taking photos, I am leaving this repair to the pros. I know my limitations and I have a great shop here at the airport where we live. So this is in their hands.
Steve McGreevy
N8293A '53 C170B
N8293A '53 C170B
Re: Outboard landing gear bracket
Steve, was the corrosion bulge on the inboard or outboard side of the bracket? How did you find it?
Re: Outboard landing gear bracket
Are you doing both gear or only one? Do you have a picture of the new P-ponk part, it would be interesting to see a comparison of an original bracket and P-ponk's version.
John E. Barrett
aka. Johneb
Sent from my "Cray Super Computer"
aka. Johneb
Sent from my "Cray Super Computer"
Re: Outboard landing gear bracket
Dave,
Inboard side, and during the annual the mechanic used an inspection camera just to take a peak inside the gear box area. The first picture in the post shows the crack that caught his attention. This was reason enough to pull the gear leg and have a more detailed look. At that point we saw the bulge caused by the corrosion, and also caused the crack.
John,
We are only doing one side. The inspection of the right side showed no anomalies. Their is a picture of the new part in the photobucket link. The new part is beefier, and rather than a stamped or extruded part, this part is milled from a solid block of aluminum.
Inboard side, and during the annual the mechanic used an inspection camera just to take a peak inside the gear box area. The first picture in the post shows the crack that caught his attention. This was reason enough to pull the gear leg and have a more detailed look. At that point we saw the bulge caused by the corrosion, and also caused the crack.
John,
We are only doing one side. The inspection of the right side showed no anomalies. Their is a picture of the new part in the photobucket link. The new part is beefier, and rather than a stamped or extruded part, this part is milled from a solid block of aluminum.
Steve McGreevy
N8293A '53 C170B
N8293A '53 C170B
Re: Outboard landing gear bracket
How did you jack the airplane? Do you have a picture of that?