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Re: Control Yoke Universal Joint Failure
Posted: Sun Apr 22, 2018 1:58 am
by combahee
wabuchanan wrote:I ended up ordering my U-Joints from Yingling aviation. They stated they get theirs from the Cessna warehouse, there were 18 of them in stock. Mine came with a manufacture date of 2015 on them.
I had to order the bolts and nuts separately as they did not come in a kit. He looked up the bolts and they were the same length, as were the original bolts. My aircraft had a washer on the forward bolt to space the nut the correct distance from the bolt head for grip. Without the washer, the nut bottoms out the threads before clamping force is achieved, so those of you that have two different length bolts are likely getting the shorter bolt for the forward hole.
No dust covers.
Installed:
Looks like the bolts are too short. At least 2-3 threads must protrude beyond the nut.
Re: Control Yoke Universal Joint Failure
Posted: Sun Apr 22, 2018 4:49 pm
by wabuchanan
ghostflyer wrote:Why no dust covers ? And a touch of grease. As said in a previous statement , I used heat shrink over my universal joints and this was done about 6 years ago and due to this discussion i have checked them out very recently and they are as good as the day I refitted them . The control cable chain needed a oil on it as it had dried out only after about 9 months . Some times its good to do a detailed inspection add hoc on a part of the airframe . A/p,s and IA,s can miss items during a 100hrly due outside pressures ,and familarity. People doing inspections doing the same item time after time have a expectation in their brain of what they think they are seeing but the reality is they miss the problem issue as it doesnt register. This is one of the reasons why I like owners to get involved in the servicing of the aircraft . I know people will bring up about occupational health and safety issues with owners in the workshop but a little training before hand is good. PLUS the owner hopefully will then realize why it costd so much to have a 100hrly. Sorry about the subject hijack.
I don't think mine has ever had dust covers, as the originals did not have them. I believe mine were the original U-joints. My AP/IA in answer to my question on grease said grease just traps dirt and wears faster so did not want me to put any on. As opposed to other greased areas where you normally clean and replace grease regularly.
I agree with your premise of owners being involved in upkeep and maintenance. I am always looking at areas on the plane and have found things before the annual that I have brought to my AP's attention. I try to do most of the mechanical work on the plane unless it is something that my AP specifically needs/wants to do himself. All my non-preventative work is done with supervision of my AP/IA. To be honest I enjoy working on the plane.
Re: Control Yoke Universal Joint Failure
Posted: Sun Apr 22, 2018 5:31 pm
by canav8
The new ones come with boots because they are greased. They are also stiffer and harder to install. Both work. Trick is do not grease them and leave them exposed for the reasons stated above if you take the boots off. D
Re: Control Yoke Universal Joint Failure
Posted: Mon Apr 23, 2018 1:08 pm
by combahee
I think the reason for the grease it to keep rust at bay and the sleeve both keeps the grease in place but also keeps the pins in place and maybe stops a total failure? I'm going to call MacFarlane and see what they say.
Re: Control Yoke Universal Joint Failure
Posted: Mon Apr 23, 2018 7:48 pm
by ghostflyer
You have hit the nail on the head, the plastic cover stops the dust and dirt and keeps the grease in and stops pins falling out and “could “ be a damper for the vibration that thats transmitted through the shalf. While this area isnt that troublesome but the age of the aircraft has to be considered and its a critical control part .
Re: Control Yoke Universal Joint Failure
Posted: Tue May 01, 2018 1:23 pm
by bsdunek
My Cessna Flyer magazine came yesterday and there is an article about McFarlane Universal Joints. Apparently there have been failures and they have issued Service Bulletin SB-9, Revision A. This concerns their replacement universal joint, Part No. MC0411257 that fits from the 120 to the 210. It applies to certain lot numbers that were sold in 2015-2016. I remembered this thread so though I would mention it. They state the sleeve over the joint provides additional support for the joint as well as preventing grit or debris in the joint.