Connecting Rods And Pistons; Removing Piston Together With Connecting Rod; Changing Connecting Rod Bearings; Checking Connecting Rod - Valtra VALMET Series Workshop Manual

21. Engine

2. Connecting rods and pistons

A. Removing pistons together with con-
necting rods
Note! Pistons and connecting rods can be removed from the
engine when the engine is attached to the tractor by removing
the front axle and the oil sump (see page 219/1).
1. Detach the engine and the lubricating oil pressure and suc-
tion pipes.
2. Detach the cylinder head.
3. Scrape off the carbon edge in the cylinder liner. If the turn-
ing edge is clearly marked, smooth it down carefully with a
scraper.
4. Remove the big ---end bearing caps and bearing shells.
Place the shells in order if they are to be re ---used.
5. Push up the piston and connecting rod with the shaft of a
hammer or similar wooden tool.
6. Remove the piston pin snap rings. Push out the pin.
Note! If the piston pin does not move under thumb pressure
the piston should be heated to 100˚C.
B. Changing connecting rod bearings
1. Clean the connecting rod and bearing shells. Fit them
together and tighten the bolts to 40 Nm+90˚.
2. Measure the I.D. using a cylinder gauge which has been
zeroed to the diameter of the respective bearing journal. If the
clearance exceeds 0,14 mm with new bearing shells, the
big ---end journals require grinding. Refer to the specifications
for the correct undersize and the corresponding bearing. En-
sure that the radii at the end of the bearing journals is not al-
tered when grinding.
3. If the piston pin bushing is worn, it should be driven out
using a suitable drift.
4. Drive in the new bushing and ensure that the oil hole is in
the correct position. Ream the bushing to 40.025 ---40.040
mm after it is fitted.
C. Checking connecting rod
The connecting rod is checked in a special fixture, intended
for the purpose (e.g. Carl Larsson).
1. Fit the big ---end bearing caps and tighten the bolts to 40
Nm+90˚.
2. Fit the connecting rod in the fixture and fit the piston pin
which corresponds to that connecting rod.
https://www.truck-manuals.net/
59
Model
6000-- 8750
1. 9. 1992
5
208,00
40 Nm+90˚
Code Page
213 3
40,025...
40,040