Landing gear u-bolt

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Paully

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Hi, changing over the old style landing gear U clamps for the new plate design U1-9805A on my 71 7GCBC, Just wondering if anyone could tell me the proper torque for 2 bolts holding the bar plate.
I did see the torque values in my service manual but that is for the original U-bolt and wonder if they might be different.
 

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Right, I’m waiting on a reply from ACA, as this is the same used on new planes.
 
Paully said:
Hi, changing over the old style landing gear U clamps for the new plate design U1-9805A on my 71 7GCBC, Just wondering if anyone could tell me the proper torque for 2 bolts holding the bar plate.
I did see the torque values in my service manual but that is for the original U-bolt and wonder if they might be different.
Click to expand...

Landing gear hardware and tail wheel rigging

I mentioned my landing gear in my introduction but thought it might be better to create a thread in the tech section where it might be of use to someone. Shortly after buying my plane I joined the Bellanca group and read up on the failure of the bent U-bolt type of main landing gear hardware...
champcitabriadecathlonforums.com champcitabriadecathlonforums.com
 
Oh great Thread, thanks for sharing. I have cut templates to confirm the angles of the top and bottom of my old leg and refurbished leg are identical. However the old gear I guess over time seems to have sprung out a little. See the pictures how the gear are matched until mid way down from the top. I’m wondering if it’s ok to go to a professional spring shop that has been in business 60 years and have them just re-arc my old to match the new.
 
I think we discussed this a while back. Bart has the answer, I believe. Normal truck spring re-arching is done cold. Be careful.

We cold-re-arch tailwheel springs. Recently one of them broke during the process. Losing a tailwheel is not a big deal - losing a main can result in a "total."
 
Ya…. I think I got my mind made up for a few bucks to send them both to The Landing Gear fellas in Renton, they will fixm up , shot peen and NDT to confirm integrity… lot cheaper than a wreck over trying to save a buck.
 
My issue isn’t the cost… it’s the time frame, seems anything i require for the plane is painstakingly long term return… however Tom did say they would be able to get at it pretty quick..
 
Dumb question here. The MLG U bolt installs with the rounded side up (round side against the gear leg) correct? As shown in Paully's photo earlier?
 
My gear is sent back for adjustment but I done a little trial run install..I’m hoping the wide plate doesn’t push up against the airframe rod that the belly fabric is attached to on the inner side ? But I’m guessing with the right torque that the rod would just push back a little ?
 
According to ACA drawings 7-1307 and 7-1589 the torque on the MS20007-38 bolt / ZEB1845-070 nut U-bolt assembly is 400-500 in/lbs. The torque on the single inboard mount MS20007-36 bolt / ZEB1845-070 nut is 650-700 in/lbs.
 
Got my gear home and getting installed. I googled and found a FAA chart on AN bolts for torque. The 4 AN 5 axle bolts call for 8.3 - 11.6 ft lbs… sure don’t seem very tight to me… guess maybe should use some paint check marker maybe? Does anyone like these a smidge tighter ?
 
The service manual gives the torque values.
Make sure you check the toe in, mine required shims.
 
My service manual gives the torques on the old landing gear U clamps but nothing on axle bolts that I can find. I have multiple shims if necessary. I see the service manual does recommend how to check the tow-in with straight edge and square…as well Jim Hayton give me a good run down with fuel and weight in the seat when checking it.
 
Jim Hayton , who I assume is a very busy man , spent at least an hour on the phone with me explaining my many questions and concerns about 7 and 8 series gear . A great man imho .
 
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