M-F Grey Cab Tips
by Dave Pepper, Boone, Iowa
Most of this list would apply to early 750/760’s
and all 850/860’s--quite a bit of this list would apply to 300, 410, 510 also.
List assumes machine is shedded and greased adequately.
1. Feederhouse :
a. (paddle feederhouse only) Run combine slowly,
watch sprockets on LH side of feederhouse to see if they run true. If they wobble, the
paddle shafts are bent.
Reach through inspection doors of feederhouse and try to move paddles back and forth. If
they rotate more than the sprockets do, the keyways in the shafts are bad.New shafts are
$250 + each. Plan on replacing all bearings on the paddles about every 3500-4000 A and
they won’t fail on you. Top shaft feeder house bearings and races are expensive--at
least $250, fail about every 1000 hrs.
b. Feederhouse floor-wears through at about 3500 hrs. Also check where
feederhouse dumps into the front beater. The tin work wears through right in front of
beater (last inch or so of feederhouse). IF caught early enough, you can build up with
weld every 500 hrs or so.
2. Bars & concaves:
Bars are shot if hex heads on bolts are beginning to
round off at corners. Concaves are much heavier than on a Deere, they usually last 2500
hrs plus, if no rocks. It’s a good thing, because a hex shaft goes through the front
of it that is nearly always frozen in place. Sometimes it has to be cut out with
hacksaw--can’t use torch or will ruin rock trap door.
3. Engine fan shaft:
Wiggle engine fan blades to make sure keyway where
pulley attaches on other end is good. Check tin work under radiator--grain flying off cyl
wears it out and it is hard to fix.
4. Water pump:
Seldom bothers. Change every 2000 hrs and it will
never fail.
5. Fuel pump:
Lucky to get 2 years out of it--fairly cheap, though.
6. Hydro trans coupler and final drives couplers:
Check for wear in splines. If previous owner greased
them a couple of times/year, they should be okay, if not, $500.
7. Unloading Auger:
At about 3500 hrs, put new bearings in gearbox on top
end (inside tube) and reverse the gears to obtain new wear surfaces.
b. Bottom end (underneath auger) and drive (by batteries) both sets of
bearings fail occasionally - every 5-6000A or so.
c. Drive chains need replaced occasionally-easy and cheap.
8. Straw chopper drive:
(below cyl gearbox RH side) this stub shaft and
bearings turn extremely fast and only last about 2-3000A. Very easy to replace brgs--about
45 min-don’t let the shaft be ruined by bad brgs--additional $200.
9. 2 speed cyl gearbox :
Grab cyl belt and rock cyl back and forth.
Slight “clunking” ok. Lots of slack or loud clunking means chain
inside is stretched, idler
bearings out, or springs broken.
10. Shaker pan :
Crawl under machine and look up just behind
feederhouse. The rippled pans will rust through if not kept clean. Front sections
are easily replaced, back is harder. I have used rusty ones for several more years by
patching with JB weld. You will finally have to replace them, though.
11. Shaker shaft & bearings:
If the previous owner has kept the shaker pan clean,
this will never bother. IF pan is heavily caked with dirt and dust, this shaft will break.
12. Wood blocks on grain pan and strawwalkers need to be inspected and
replaced if they have too much play. You will never break a strawwalker if these blocks
are replaced as needed. Perforated top of walkers need inspected and any cracks brazed
about 2 x per year. Pretty easy, maybe 1 hr or less of inspection and brazing time.
Don’t do this and top sections of walkers will break off completely and let straw and
shucks onto grain pan, plugging machine and possibly doing more damage.
13. Canvas curtain behind straw walkers:
Make sure its there and is good. New one is
really expensive.
14. Straw chopper:
Make sure back of combine has no excessive vibration
when running or your chopper needs balanced - a day’s work to remove and reinstall
plus $200 machine shop charge and $75 for brgs.
15. Final drives:
Trouble-free if kept full of oil. Ditto for 4 speed
trans.
16. Hydro cable:
If combine goes forward well but backs up extremely
slow, this cable is stretched--costs about $150 and takes 3-4 hours to change.
17. Hydro:
Make sure you can stall the motor by stomping hard on
brakes--if not, hydro is weak - $1500-2000 if you remove and reinstall yourself.
18. Clean grain augers top and bottom. Check condition of flighting and
tubes augers run in. Bottom tube wears out at inspection door. There is a company in Ohio
that makes an insert for this.
19. Clean grain and tailings sprockets and conveyor chains. If kept
adjusted properly, these will last at least 3000 hrs. There is a double bearing on the
driven side of clean grain auger; trouble-free if greased. I always change them when
re-flighting this auger.Sprockets $50 ea. Both conv. chains about $500.
20. Re-thresh cyl :
Open up door over the little re-thresh cyl. Hold
belt, and try to rock cyl back and forth. If it will move (and usually “clunk”)
the keyway in the re-thresh cyl shaft is shot. Very common problem.
Parts to keep on hand:
Sending unit for shaft monitor
Several each of the common idler bearings
Feederhouse paddle bearings and a couple of the flanges in case you
ruin them when torching off old brgs
Dash-mounted AC/fan switch-- lots of amps goes through and they
don’t last long
Rubber feederhouse paddles (top set are different from the rest)
Cyl belt
Any belt showing wear
1” std lock-collar brg (fits several places)
Brgs for driveshaft on feederhouse (where heads couple to)
Double 60 rollerchain (under cab-drives entire feederhouse) connector
and half links also
#50 and 60 rollerchain connector and half links
Set of friction discs for feederhouse slip clutch
Engine fan belts (matched set) and idler brg
Regreasable brgs--cyl, beater etc.--keep them greased and the only one
that will ever bother is LH side of rear beater (Under HUGE pulley)