How Touchy is your Trim Wheel?

[PT20J]

1 hour ago, skykrawler said:

I felt the stab trim in my airplane was stiff and needed attention.   I read a number of forum postings and went after it during an annual.  There is very little in the maintenance manual about removing the jack screw assembly bolted in at the aft bulkhead of the tail cone.  For the '82 J the most difficult part is to get the separation of the square sectioned link that attaches to the jack screw shaft in the tail cone.   Its like the system is designed so that if all the bolts fell out it still wouldn't come apart and would still work.     I finally go it out and cleaned the screw thoroughly and opened the bearing box expecting slag and it was perfectly clean light oil and perfect bearings.   Put it all back together - probably spent 6 or 8 hours on the job and the trim still feells stiff.

But at least I know.

Service Manual Lube chart calls for Aeroshell Grease 7 on the jackscrew and actuator. I believe there are also shims to set bearing preload in the actuator.

Skip

[skykrawler]

Point is.....relative to the topic....how the trim feels is subjective.     I went to the trouble to make sure there was no problem.  Do I regret it? No because I now know  the condition of the system.

[Andy95W]

On 4/2/2020 at 8:38 PM, PT20J said:

Service Manual Lube chart calls for Aeroshell Grease 7 on the jackscrew and actuator. I believe there are also shims to set bearing preload in the actuator.

Skip

When I opened mine up for cleaning and fresh grease, I misread the service manual and used the wrong grease.  It was very noticeable in flight- very stiff.  So I've officially done mine twice, I must be an expert!

[PT20J]

Practice makes perfect