Bolt AN3-4A
WasherAN960-1L Flap Position
Gromment MS35489-33 Sender

Nut MS20365-1032C
Motor Assembly
SKETCH A
SKETCH B

Flap System Installation 
Figure 402 
EFFECTIVITY: 
040-999  27-50-00 PAGE 5Jan 10/90 

PIPER AIRCRAFT

PA-42-720 (Advanced Trainer)
MAINTENANCEMANUAL
A. Flaps(continued)
8. Removalof Flap Transmissions (referto Figure 1)
(a)
Lowerthe flap and remove the access plateon the aft undersideofthe wing andthe false spar area,bothof which are at W.S. 92.50and 42.50.

(b)
Disconnectthe transmission tubefrom the flap horn bracket.

(c)
Removethe safety wireand disconnect theflexibleactuatorshaft.

(d)
Removethe spreader bushingand washers from betweenthe transmissionattachment brackets.

(e)
Remove the transmissionfrom its mounting brackets and draw the unit through theaccess openinginthe wing falsespar.

9. Installation  (referto Figure 1) of Flap Transmissions
Determinethat the correctflap transmission assembliesare beinginstalled by checkingthe part
numberson the assemblies with information In the latest PA-42-720 (AdvancedTrainer) Parts
Catalog.
(a)
Lubricatethe flap transmissionassemblyin accordance with lubrication chart,12-20-00.

(b)
Insert the transmissionthroughthe access openingin the wing false spar and attachto its mountingbrackets.Toallow the transmissionto rotate, tightenthe attachment bolts (only fingertight)and safety.

(c)
Installthe spreader bushing with onewasherbetweeneach mounting bracketand bushing. Installthe through bolt and secure.

(d)
If working with the left transmission, connectthe flexible actuatorshaft and safety with MS20995C41safetywire. Attach therightflexible shaft during riggingandadjustment.

(e)
Safety wire (MS20995-C20) protectivecap on outboardtransmission.

(f)
Check the flap riggingand adjustment.

(g)
Installaccessplates.

10.Disassembly  (Referto Figure 2)of FlapTransmission
CAUTION:  CALCOFLAPTRANSMISSIONDISASSEMBLYANDASSEMBLYPROCEDURE ARE INCLUDEDIN THIS MAINTENANCE MANUALFORINSPECTION PURPOSESONLY.CALCODOESNOTRECOMMENDOVERHAULIN THE FIELD.
(a)
Removesafetywire, bolts and rear housing.

(b)
RemoveO-ring.

(c)
Straightentangon lockwasher sothat locknut andlockwirecan be removed.

(d)
Removeballscrew and tubeassembly.

(e)
Removebearingassemblyand shim.

(f)
Removewormgear, key and shim.

(g)
Removefront bearing assemblyfrom housing.

(h)
Removeprotectivecap if used.

(i)
Removescrewsand both output flanges.

(j)
Push worm shaft and bearings out of housing.

(k)
RemoveO-ringfrom housing.

(I)
Bumper washer is attached tothe housing with Locktite adhesive. Use Locktite solvent, if necessaryto remove washer.

(m)Removesafetywire, screws, and wiper block and wiper from ball screw and tube assembly.
(n) Place a container or tray under the ball screw and tube assemblyand remove thetwo screws securingthe ball return tube to the ball nut.
EFFECTIVITY:
040-999

Jan 10/9027-50-00
PIPERAIRCRAFT
PA-42-720(AdvancedTrainer)
MAINTENANCEMANUAL

A. Flaps(continued)
of FlapTransmission
10. Disassembly  (continued)
CAUTION: DO NOTATTEMPTTO REMOVETHEOUTPUTTUBE FROMTHEBALLNUT. THEOUTPUTTUBEIS FORMROLLEDTOTHE BALLNUTDURING MANUFACTUREAND MUSTBESERVICEDAS AN ASSEMBLY.
(o)Carefullyremovetheballreturntubeandseparatethetwohalfsallowingthesteelballsto drop
theballscrewuntilall steelballs(67-69intoacontainer.Turntheballnutoverandrotate

total)havedroppedout,allowingtheballscrewto be removed fromtheballnut.
11.Assemblyof Flap Transmission(Referto Figure 2)
(a)Assembleballscrewandtubeassemblyasfollows:
(1.) ApplyathincoatofAeroshellNo.7 grease, orequivalenttoentirethreadofballscrew.
(2.) Insertballscrewpartwayintoballnutandoutputtubeassembly.
(3.) Layonehalfofballreturntubeflatona table andfill groovewithsteelballs. Placethe

otherhalfoftheballreturntubeontheassembledballs.
NOTE: AlightcoatofAeroshellNo.7orequivalentmaybeusedto holdtheballsin place.
CAUTION: DO NOTALLOWTHE BALLSTO ROLLOUT EITHERENDOFTHEBALL NUT.
(4.) Inserttheremainingsteelballsintotheballnutbyplacingtheminoneofthehalesand turningtheballshaftuntilalltheballsareinplace.
witclampandtwoscrews.

(5.) Carefullyinstalltheballreturntubeontotheballnutandsecure
Applya coatof DowComing732RTVadhesive,orequivalenttotheballreturntubeto sealexternalopenings. (6.) Applya lubricantconsistingof20%AeroshellNo.7greaseand80%MobileJetII Oil oran equivalentmixture,tothewiper.Installwiperandwiperblockontotheballnutandsecure with screws. (7.) Safetywire (MS20995-C20)the screwson the ball nut.
　
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