Gear Bolt Wear (Loose Legs)

[mosquito]

Hi everyone,

My 1996 O-320 -6 is down for her 2nd condition inspection (since purchase by me), and we've discovered the bolts that mount the gear legs to the engine mount have wallowed out a bit. With the plane jacked up and the wheels off, the gear legs can be moved around, by hand, in their sockets.

We suspect the gear bolt holes were drilled to match the bolt, as opposed to slightly undersized/reamed. I've found a number of threads about that... but I haven't found anything about what to do when/if the bolts start loosening up.

Any ideas? The A&Ps doing the inspection suggest simply reaming and upsizing the bolt. Has anyone been through this?

As always, thanks!

-jon

 

[mtnflyer]

Gear legs

The best way to cure this is to lock the gear legs in place,( I used a piece of 4 by 6 angle steel). Then ream out the holes with a brown and sharp tapered reamer and install tapered pins ( from aircraft spruce). I did this on my 4 about 15 years ago and they are still tight.. I should have taken pictures but didn't. Dave

 

[Richard@Langair]

I prefer to just use the next oversize bolt

I like the idea of the next oversize bolt the best. I think Gahco on the forums here has the appropriate bolts and reamers.

The bolts I am thinking of would be either a 1/64 over or 1/32 over. This amount of material is relatively easy to ream and does not require redrilling the hole that is already there.

If you try to redrill one of those holes, you will likely create more problems than you already have.

The taper bolt idea usually works well too, but if the gear leg is not 100% tight against the socket when you are reaming it, you will never get the gear leg tight. If you do get it correct though, it is a very good solution.

Just my opinion is all.

Richard @ Langaire

 

[DrHolling]

Here is the link to the taper pin install info:

http://www.matronics.com/wiki/index.php/Nose_Gear_Strut

I did this to mine while building.

Dave

 

[Bavafa]

There is a lock tight (forgot the #) that you can use in the gear leg and its socket and then put the bolts in place. Those who have used the lock tight have had great result. I am sure if you search for it, you can find exactly which lock tight to use.

Good luck

 

[AlexPeterson]

Without having a clue as to how loose yours are, it is possible that a close tolerance AN bolt will fix the problem. A couple thousandths of an inch clearance can really make things seem loose.

 

[mosquito]

There is a lock tight (forgot the #) that you can use in the gear leg and its socket and then put the bolts in place. Those who have used the lock tight have had great result. I am sure if you search for it, you can find exactly which lock tight to use.

I think this is the locktite thread: http://www.vansairforce.com/community/showthread.php?p=368920
Interesting for sure, but I think mine might be too enlarged now.

Without having a clue as to how loose yours are, it is possible that a close tolerance AN bolt will fix the problem. A couple thousandths of an inch clearance can really make things seem loose.

Very good idea... but there's about 0.0030" of play longitudinally, so I think we'll need to go bigger

Thanks for everyone's input, I really appreciate it! So far it's looking like taper pin or oversized bolt, I think.

-jon

 

[AlexPeterson]

I think this is the locktite thread: http://www.vansairforce.com/community/showthread.php?p=368920
Interesting for sure, but I think mine might be too enlarged now.



Very good idea... but there's about 0.0030" of play longitudinally, so I think we'll need to go bigger

Thanks for everyone's input, I really appreciate it! So far it's looking like taper pin or oversized bolt, I think.

-jon

Assuming the leg and mount holes are both the same size, .003" play longitudinally will be corrected by a bolt that is .0015" bigger diameter. A close tolerance bolt will probably do it. I don't recall, but if it is -5 bolt size, the standard AN diameter is .309 to .312, probably runs in the middle or .3105. Close tolerance is I believe .3125 +/- a few tenths.