ok, you posted great evidence.
4th gear is not a gear at all, (magic) it is 1:1 direct drive and 5th is actually overdrive. and is great symptoms this. told by you.
gee the shifter tip , plastic tip ID #27 is bad as all are this old and now rattles like mad.(shifter tip ,metal to metal failure does)
http://fixkick.com/tranny/shifting/rails.JPG
a transfer case seal right> (i bet) was worked on, (4wd has 2, one to rear and one seal to the front axle.
They said they also replaced the rear lower bearing.<< hints of transfer case 4wd , front drive bearing to front axle. and its seal sure can leak.
(on what ?_)
the rear seal is a part on the transfer case. unless they pulled the transfer case to get the 5sp box actual, did they?
I guess, u-joints bad too.
a U-joint can fail and if ignored, the vibration (huge) beats the seal front of it to death. by it would make noise in 4th gear (1:1 fake gear, main shaft is locked up)
please be clear on what they touched,
The right side of the 5speed box the bolt there must never be removed. only the female 4sided 10mm plug for level checks, is the level of GL4 lube good?
the wrong bolt pulled wrecks the gear alignment.(reverse that always spins, , clutch out.
see why here, reverse gear makes noise,not now aligned,
http://fixkick.com/tranny/images/images/problems1.jpg
there are many seals here.(5)
front of 5speed pinion
rear of 5speed, seal
front of transfer case seel
rear of transfer case seal upper to rear prop shaft
transfer case lower to font prop haft seal.
the casing from 5sp to xfr case , center empty case (adptor) is dry,
there is no oil in the center case.
there is an open always tiny drain hole in the bottom of the center case that if drips oil we know 1 of 2 seals above are bad. deep inside.
when the 1,2,3 gears make noise and tranny fluid is full up to right filler hole plug . is it, never ignore this at 60k mile tune up, it's just simple check.
at noise rest your HAND on the shift lever top (firmly down) does the NOISE END??????????????
finding noise that only happens moving fast is not easy , nor safe.
I use a Steelman electronic stethoscope to find noise with microphone clamps. 10x more safe way to find moving noise.
noise., moving from tranny (seems)
does noise in if you left foot slam in the clutch pedal.? to floor,
no noise ever in neutral
noise only of left foot rides the clutch pedal, bad TOB throw outbearing
5sp or transfer case fluids low or OMG DRY
bad U-joints
makes noise in 2wd but not 4High.4wd. or the noise only in 4wd. or both.
or noise ends as next poster said, hand resting on gear shift know ends noise, yes, then part ID 27 is bad (plastic,or now missing)