Bearing in 737 yoke column

[NAX228]

I am setting up my dual yoke for the sim, but have got a problem with the capt yoke.
For the aileron movement I will use a 34mm (sanded to the correct thickness) round wood molding to a flywheel that run wires.
I have noticed a little unevenness when I turned the yoke, but after gently tapping in this molding, the movement is all fudged up... unusable. I will have to replace the lower bearing that support the shaft for the aileron movement, and wonder if any of you have dismanteled the yoke column to get to those bearings before.
I know Jack had a cut yoke, but I dont know if this cut was over or under the bearing.

any tips for this operation? Is the column easy to open/dismantle?

[Gallie]

Hi,

Why use wood in this set-up? these parts have to withstand prety big forces...

The collumns are pretty easy to open, but it will take some force. It might also be smart to do this with 2 persons.

Unscrew the 4 screws that hold the top elbow inplace. (this alone could take some force)

If the elbow doesnt come off with simple pulling force you have to try a different approach.
In this case it may be easy to lay the column on the ground. Use something to protect the column from he ground and visa versa. then put a wooden block to the elbow and start hamering the elbow off. (this worked for me)

Take in mind that the lower bearing in the column is a "neadle bearing". They damage quickly.... and could be difficult to replace. Use WD40 to clean it up, put enough grease back in the bearing when you close it up again.

If youd like i could try to open mine and take some pictures for you.

Good luck!

Mike

[jackpilot]

Agreed. wood is a no no.
there are aluminum rods all sizes to do the trick, secured with bolts.
Could you show some pics, would be easier to help.
Usually if you unscrew the bolts situated on the column below the elbow, the column comes off easily.
(usually!)

[NAX228]

Thanks for good explanation. I will try this tonight and also take some pics.
I do agree on the woodpart, but it actually seems quite rigid enough for it's purpose.

More coming and thanks again!

[NAX228]

I find 2 set of bolts on the bottom of the colomn, but these aint screws...
There 4 screws on the top of the colomn, see pics.

http://lh6.ggpht.com/_6cfkT1JgF-0/TTcvENHabyI/AAAAAAAAAKI/MtTkCck7bsM/s912/19012011315.jpg

http://lh3.ggpht.com/_6cfkT1JgF-0/TTcvETjK2PI/AAAAAAAAAKM/HvY9ASUze7w/s912/19012011318.jpg

removing 4 screws let me slide off the colomn.


http://lh6.ggpht.com/_6cfkT1JgF-0/TTc4UQdZEVI/AAAAAAAAAK0/iOcu4CjJ1a0/s800/19012011319.jpg

The needlebearing seems ok, but dry. I'll oil it and see if things get better. If not I'll take a look inside the top.

http://lh3.ggpht.com/_6cfkT1JgF-0/TTc4UBKbzsI/AAAAAAAAAKw/9pn4wg-14PM/s800/19012011322.jpg

Update: Cleaned the needle bearing with etanol and oiled it. Run very nice. I tried to turn the yoke before sliding the housing back in place, and the feeling was the same.
The bug is in the upper housing.
There is a big umbraco on the back of the "cup". Is this the one I'm supposed to unscrew to remove the yoke and check things inside the cup/upper housing?

[jackpilot]

I was talking about those near the yoke.
Did'nt have the bottom part, my column was cut above.
Someone else here will help for sure.

[NAX228]

ahhh...ok
I have a albow on the lower part as well, and since I thought the problem was "down there" I reconed it was that albow. Reading your post now, I understand what you mean.

Ever opened the top? Have to check in there as well. It's more or less useless as is.

[jackpilot]

Check 5th  down by Garys
http://www.cockpitbuilders.com/community/index.php?topic=687.msg6553#msg6553

[NAX228]

yup... there is was. Thanks a bunch.
I see you have done a nice job refinish it, and that is really something for me to think of to. Lots of nasty scratches in my yokes, and the capt. yoke is the worst
Would love to keep the white in the engraved letters though. It will be written on the "to-do-list".