140 gear leg adjustment

[8224]

I strongly advise against using the lifting lugs on the engine. I saw the top of the engine literally pulled out on an older Bonanza in Tucson years ago. The lugs are for lifting the engine, not the airplane.
Steve Hawley

[pabloj3]

Hi all -

I am about to go through this in my 1946 C-140. My RH wing is significantly lower. I'm a bit confused as to whether the right course of action is to replace the PN 0441115 shims (or add?) or to be adding washers to the main landing gear bolt that sits at the end of the spring?

Anybody has pictures of this that they could share? Also - how many washers would be acceptable, or does anyone know how much difference one or two washers make at the wingtip?

Thanks everyone!

Pablo

[6277]

Be extremely cautious when removing the bolt that holds the shims in place. There is a nut-plate in a nearly inaccessible "U" channel that the bolt attaches to. If the bolt is corroded, the rivets holding the nutplate might (will in my experience) break, but the nutplate will lodge itself in the channel and you won't know this has happened until you try to put everything back together. I replaced a bent gear leg years ago...

[pabloj3]

Thank you, Ray! That's great advice!

But what you're saying is I should at shims? Get thicker ones? Or do I adjust the height via adding washers to the main bolt at the end of the spring?

[6643]

The washers are the shims. They are not shown in the parts manual. The parts sometimes referred to as shims (3) are called "wedges" and wedge the gear leg in the slot in the gear box. They are not adjustable.

The adjustment is accomplished by adding washers between the end of the gear leg and the gear box on the NAS147 bolt (6) at the inboard tip of the gear leg. The washer (7) goes under the head of the bolt against the top of the gear leg and is a special washer with a chamfer to accommodate the fillet where the head of the bolt meets the shank.

Before you start adjusting the gear legs ensure the wheels are sitting on level ground and the tires properly inflated. If there are washers on the high side, remove them first before adding washers to the low side. If you're removing washers make sure the threads don't bottom out on the nut. You can move the washers from under the gear leg to above, just remember to keep the chamfered washer against the head of the bolt.

Gear leg attachment.jpg (37.37 KiB) Viewed 1582 times

Oh, and don't loosen that big bolt with the weight of the plane on the gear!

[pabloj3]

Dear John - Thank you so much for that! Now its clear - I do not need to mess with the wedges.

Would you happen to know where to source those washers, and an idea of how much it would take to fix about 4" difference in wingtip height?

Also, suppose it would be wise to replace the main bolt and its nut. Would you know where to source those too?

Thank you kindly! Much appreciated.

Pablo C. Branco

[6643]

The washers are off-the-shelf AN960-716 washers.

Cessna says a 3" difference is acceptable, so likely you'd only need one washer.