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Mike Noel
June 1st 04, 02:07 AM
The fellow who did my annual asked me to order a jack screw because he can
see a little wiggle between the screw and the cable drum. He wasn't sure
which part was worn, but suggested we start by replacing the screw and then
also replace the drum if the problem persists.

I would like to survey the experiece of the group before ordering the jack
screw. Is the screw more likely to wear than the cable drum, or do they
both tend to add equally to a loose fit?

--
Regards,
Mike

http://mywebpage.netscape.com/amountainaero/fspic1.html

Bob Noel
June 1st 04, 03:03 AM
In article >, "Mike Noel"
> wrote:

> The fellow who did my annual asked me to order a jack screw because he
> can
> see a little wiggle between the screw and the cable drum. He wasn't sure
> which part was worn, but suggested we start by replacing the screw and
> then
> also replace the drum if the problem persists.
>
> I would like to survey the experiece of the group before ordering the
> jack
> screw. Is the screw more likely to wear than the cable drum, or do they
> both tend to add equally to a loose fit?


the screw is steel. The bushing is a softer metal. Guess which
one is worn.

--
Bob Noel

G.R. Patterson III
June 1st 04, 03:30 AM
Mike Noel wrote:
>
> The fellow who did my annual asked me to order a jack screw because he can
> see a little wiggle between the screw and the cable drum. He wasn't sure
> which part was worn, but suggested we start by replacing the screw and then
> also replace the drum if the problem persists.

I would do one of two things. If I could tolerate the down time, I would take the
assembly apart, find out what's wrong, order the correct part, and reassemble the
unit when the part arrives. If I could not wait that long, I would order both parts.
When the parts came in, I would disassemble the unit, replace whatever is worn, and
try to get a refund on the unused piece (or sell it).

Sounds like this guy wants to get paid for taking the thing apart twice.

George Patterson
None of us is as dumb as all of us.

Aaron Coolidge
June 1st 04, 04:07 AM
Mike Noel > wrote:
: The fellow who did my annual asked me to order a jack screw because he can
: see a little wiggle between the screw and the cable drum. He wasn't sure
: which part was worn, but suggested we start by replacing the screw and then
: also replace the drum if the problem persists.

: I would like to survey the experiece of the group before ordering the jack
: screw. Is the screw more likely to wear than the cable drum, or do they
: both tend to add equally to a loose fit?

Be very sure that the 'wiggle' is between the jack screw & trim drum. It's
usually between the trim drum and the supporting plates because the bushings
in the supporting plates are worn.

PS, when mine wore out after 5700 hours it was the trim drum. The new trim
drums don't look like the old trim drums, but they work the same. Oh, and
some mechanics don't seem to be able to follow the procedure for properly
winding the trim drum. Check the trim from full nose-up to full nose-down
after it's replaced. My guy wound one too few turns on the drum, and the
cable came off and jammed the trim full nose down (during my post-
maintenance checks).

--
Aaron Coolidge (N9376J)

Jay Masino
June 1st 04, 12:10 PM
Mike Noel > wrote:
> I would like to survey the experiece of the group before ordering the jack
> screw. Is the screw more likely to wear than the cable drum, or do they
> both tend to add equally to a loose fit?

I just did mine at the last annual. Mine had been wiggling for a while,
and my mechanic felt it had gotten too severe. I can't honestly remember
which parts had the most wear. I think everything had some. We basically
replaced everything, because my mechanic happened to have everthing in
stock. We even had to replace one of the steel plates that the bushing is
pressed into. It's a good feeling to know everything's perfect, now.

--- Jay (67 Cherokee)



--
__!__
Jay and Teresa Masino ___(_)___
http://www2.ari.net/jmasino ! ! !
http://www.oceancityairport.com
http://www.oc-adolfos.com

Bob Chilcoat
June 1st 04, 02:46 PM
Last week while changing the oil (owner maintenance) we took the upper tail
cone off to examine ours more carefully, since I had noticed some
significant looseness during preflight a few weeks ago. It had not been
changed at annual a couple of months ago, but now has major play. Once we
had the tailcone open, we could see that the jackscrew moves at least an
eighth of an inch fore and aft, changing its angle relative to the tail by
several degrees. On addition, you can move the screw laterally inside the
drum almost half of the thread depth. When we saw that it was not just a
bit of axial play, we decided to change it ASAP. We were a bit cross that
it wasn't caught at annual, but the A&P said that if they had seen that much
play, they would have replaced it. He speculated that it might have been in
a "tight" point in its travel when they checked it. I'm not convinced, but
it's not worth arguing about. We might try and get some relief on the labor
to put it in. I understand that the replacement comes as a kit with drum,
screw, and new cables. If they had done it at the annual, the floor would
already have been up. We haven't had a price yet, but I don't expect it to
be cheap.

--
Bob (Chief Pilot, White Knuckle Airways)

I don't have to like Bush and Cheney (Or Kerry, for that matter) to love
America

"Jay Masino" > wrote in message
...
> Mike Noel > wrote:
> > I would like to survey the experiece of the group before ordering the
jack
> > screw. Is the screw more likely to wear than the cable drum, or do they
> > both tend to add equally to a loose fit?
>
> I just did mine at the last annual. Mine had been wiggling for a while,
> and my mechanic felt it had gotten too severe. I can't honestly remember
> which parts had the most wear. I think everything had some. We basically
> replaced everything, because my mechanic happened to have everthing in
> stock. We even had to replace one of the steel plates that the bushing is
> pressed into. It's a good feeling to know everything's perfect, now.
>
> --- Jay (67 Cherokee)
>
>
>
> --
> __!__
> Jay and Teresa Masino ___(_)___
> http://www2.ari.net/jmasino ! ! !
> http://www.oceancityairport.com
> http://www.oc-adolfos.com

MikeM
June 2nd 04, 12:20 AM
Mike Noel wrote:
> The fellow who did my annual asked me to order a jack screw because he can
> see a little wiggle between the screw and the cable drum. He wasn't sure
> which part was worn, but suggested we start by replacing the screw and then
> also replace the drum if the problem persists.
>
> I would like to survey the experiece of the group before ordering the jack
> screw. Is the screw more likely to wear than the cable drum, or do they
> both tend to add equally to a loose fit?
>
I just went through this with my PA22/20. There are flat washers
(used as thrust washers) above and below the block though which
the jackscrew shaft runs. We were able to get the play out by
the replacing worn washers...

Google Groups it!

MikeM
Pacer '00Z
Skylane '1MM

June 5th 04, 08:02 AM
On Tue, 1 Jun 2004 09:46:14 -0400, "Bob Chilcoat"
> wrote:

snip

>play, they would have replaced it. He speculated that it might have been in
>a "tight" point in its travel when they checked it. I'm not convinced, but
>it's not worth arguing about. We might try and get some relief on the labor
>to put it in. I understand that the replacement comes as a kit with drum,
>screw, and new cables. If they had done it at the annual, the floor would
>already have been up. We haven't had a price yet, but I don't expect it to
>be cheap.

How does "missing" it during annual translate into a discount for
repair? Taking the tailcone off to access it for inspection or repair
takes about 5 minutes. Popping the rear seats and yanking the "floor"
could also be accomplished in about 5 minutes, but there is no reason
to remove it to change out the trim drum or screw.

Have never heard of a "kit" to replace a trim drum, doesn't mean it
doesn't exist, tho.

The oilite bushings that the drum rotates in/on are cheap, with the
drum out, I'd change 'em. Unless the cable is frayed, I'd leave it.

Very seldom is the steel screw worn, but it is quite common for the
aluminum drum to be worn both internally and where the aforementioned
bushings ride.

It takes about ten minutes to yank the screw and try it in a new drum.
Somebody that knows how to do it could swap out the drum and the upper
and lower bushings in about two hours. As others have pointed out,
somebody that doesn't know to do it is likely to screw it up.

TC

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