Basic Instructions - New Holland T4.90 Tier 4B Service Manual

Basic instructions

IGN.
Before commencing any work on the vehicle, always disconnect and isolate the negative lead from the battery, unless
otherwise indicated for a specific operation (for example: an operation to be carried out with the engine running), on
completion of which the negative lead should be disconnected before proceeding with the work.
SHIMMING
At each adjustment, select the shims measuring them one at a time with a micrometer and summing the values
obtained: do not measure the complete pack of shims all together or rely on the nominal values indicated on the
shims as these could produce incorrect measurements.
ROTATING SHAFT SEALS
For correct rotating shaft seal installation, proceed as follows:
• before assembly, allow the seal to soak in the oil it will be sealing for at least thirty minutes;
• thoroughly clean the shaft and check that the working surface on the shaft is not damaged;
• position the sealing lip facing the fluid; with hydrodynamic lips, take into consideration the shaft rotation direction
and position the grooves so that they will deviate the fluid towards the inner side of the seal;
• coat the sealing lip with a thin layer of lubricant (use oil rather than grease) and fill the gap between the sealing lip
and the dust lip on double lip seals with grease;
• insert the seal in its seat and press down using a flat punch; do not tap the seal with a hammer or mallet;
• whilst inserting the seal, check that it is perpendicular to the seat; once settled, make sure that it makes contact
with the thrust element, if required;
• to prevent damaging the seal lip on the shaft, position a protective guard during installation operations.
O-RING SEALS
Lubricate the O--RING seals before inserting them in the seats, this will prevent them from overturning and twisting,
which would jeopardise sealing efficiency.
SEALERS
Apply one of the following sealing compounds on the mating surfaces marked with an X: L
5205.
Before applying the compound, prepare the surfaces in the following manner:
• remove any incrustations using a wire brush;
• thoroughly de--grease the surfaces using one of the following cleaning agents: trichlorethylene, petrol or a water
and soda solution.
BEARINGS
When installing bearings it is advised to:
• heat the bearings to 80 ÷ 90 °C before fitting on the shafts;
• allow the bearings to cool before installing them.
ROLL PINS
When fitting split socket elastic pins, ensure that the pin notch is positioned in the direction of the force required to
stress the pin.
Spiral roll pins, on the other hand, can be fitted with any orientation.
INTRODUCTION
47878245 08/06/2015
9
® 518™ or L
OCTITE OCTITE
®