43
Operation
Rear tracks with automatic variable track P.A.V.T.
wheels - Mod 7860-8860
Tractors Mod.7860 and 8860 can be equipped with
automatic variable track «P.A.V.T.» wheels on request.
Depending on how the wheels is mounted, eight track
widths can be obtained with successive 50 mm (1.95
in.) increases at a time for each wheel, thus a total 100
mm (3.9 in.) at a time for both. See table.
NOTE:
the maximum track width must only be used
for light loads. Pay particular attention when driving
with this track width.
Track is adjusted in the following way with P.A.V.T.
wheels (Fig. 23):
1.Remore the then fix the stops (A) of each guide in
the required position.
2.Slacken off all the bolts (B) that fix the disc to the
rim by 3 turns and then oil them.
3.Move forwards or backwards, braking the wheel
opposite to the one being adjusted until the
guiding blocks touch the stops.
4.Position the remaining stops so as to lock the disc
in both wheel turning directions.
5.Tighten bolts (B) in a diagonal and progressive
way until reaching a final driving torque of 28
daNm (209 lbf ft). It is extremely important to
ensure that the tyre is inflated to the established
pressure since this can influence the way the
wheels are clamped.
6.Adjust the other wheel in the same way.
If the wheel is removed to invert the central disc, make
sure that the tyre is fitted with the tread tips pointing
in the forward turning direction as indicated by an
arrow on the tyre itself.
Tighten the nuts that fix the disc to the wheel hub (C)
to a 28 daNm (209 lbf ft) torque.
Warning:
Take great care when demounting the rear
wheels. Owing to their weight, it will be necessary to
use a hoist to remove the shift the wheels.
Fig. 23
Normal
Turned
mm
mm
1
1324
1506
2
1424
1606
3
1524
1706
4
1624
1806
5
1724
1906
6
1824
2006
Position
Wheels and tyres
Regularly check that the front and rear wheel nuts are
fully tightened
. The values are given on the previous
pages.
Type pressure must be checked and adjusted before
using the tractor. Make further checks at
regular
intervals.
The tyre inflation pressures are given in the «Technical
Specifications» chapter of this manual.