Volvo B27A, B27E, B27F, B28A, B28E Service Manual
...
•^
Service Manual
Repairs
and maintenance
Section 2 (21)
Reconditioning
engine
B
27,
B 28
260 1975-1983
*#
books4cars.com
4850 37th Avenue South
Seattle,
WA 98118
U.SA
B27A-B27E-B27F-B28A-B28E-B28F
1
What do these designations mean?
B28E
A = carburetted engine
E = fuel injected engine
F = fuel injected engine "USA models"
1
The B 28 is in principle a B 27 with a larger bore.
28(27) =
ce
•
B = petrol
(g«
Engine type
B27A
B28A
B27E
B28E
B27F
B28F
pacity
jsoline)
Model year
1976-1979
1980-1982
1975-1980
1981-1983
1976-1979
1980-1982
Volvos are sold in versions adapted for different markets.
These adaptions depend on many factors including legal,
taxation and market requirements.
This manual may therefore show illustrations and text
which do not apply to cars in your country.
Group
21
Reconditioning engine
r
Contents
Contents
Important
information
Specifications
Special tools
Page
... 2
... 2
.. 11
Thread repairs
Operation
A
1-14 14
Reconditioning engine
Disassembly B 1-19
Cleaning and inspection C 1-41
Assembly D 1-35
Cylinder head, reconditioning E 1-26
Assembly (cont.) F 1-33
20
26
38
46
52
Index page 62
r
r
This manual deals exclusively with the overhaul of the
engine.
For work carried out on the engine when fitted in the car,
and for engine removal and installation, please refer to the
separate manuals.
Order number: TP 30447/1
We reserve the right to make alterations.
Group
21
Reconditioning engine
Important information
Important information
Tightening torques
Nearly all of the B 27/28 engine is made of aluminium
alloy.
The
threads
are
tapped directly into the alloy. For
this reason it is extremely important that all of the bolts
are tightened to specified torque.
Two types of tightening torques are used in this manual:
I.
Tightening torque 40
Nm
(30
ftlbs)
= a torque
wrench must be used.
II.
Tightening torque
40
Nm
(30
ft.lbs) = correct value,
however it is not necessary to use a torque
wrench.
Specifications
Group 20 General
Engine serial number and part number
Located on a plate in front of the oil filter.
On B 28 E/F
1981-
models: located on the rear of the
right-hand cylinder
head,
shows the last three digits of
the part number.
Group 21 Reconditioning engine
f^
Specifications
Group 21 Engine block
CYLINDER HEAD
Height
New -
111.07
mm (4.373 in)
Max. warp is 0.05 mm over 100 mm.
NOTE!
Do not level a warped cylinder head, replace it.
Cylinder head gasket thickness
1.14-1.50
mm
(0.045-0.059
in)
CYLINDER BLOCK
Cylinder liners
Pistons and liners are matched sets.
Cylinder liners are marked by 1, 2 or 3 cuts in the upper edge of
the liner.
B 27 B 27
Bore,
liners marked 1 (A-marked piston) 88.00-88.01 mm 91.00-91.01 mm
(3.4646-3.4650
in)
(3.5826-3.5830
in)
2 (B-marked piston) 88.01-88.02 mm
91.01-91.02
mm
(3.4650-3.4654 in) (3.5830-3.5835 in)
3 (C-marked piston) 88.02-88.03 mm
91.02-91.03 mm
(3.4654-3.4657 in) (3.5835-3.5838 in)
Liner height above block face
0.16-0.23
mm (0.0063-0.009 in)
Shims for adjustment of liner height:
thickness, blue paint marking 0.070-0.105 mm (0.0027-0.0041 in)
white paint marking
0.085-0.120
mm
(0.0033-0.0047
in)
red paint marking 0.105-0.140 mm (0.0041-0.0055 in)
yellow paint marking 0.130-0.165 mm (0.0051-0.0064 in)
PISTONS
Pistons for B 27
Pistons and liners are matched sets.
Two different manufacturers supply pistons, see next page
for specifications.
f
\
Demolin
Mahle
Group 21 Reconditioning engine
Specifications
DEMOLIN
PISTONS (B 27) B 27 A
1976-1979
B27E 1975-1978
B 27 F 1979 1976-1978
Height, overall 74 mm (2.9134 in) 63.4 mm (2.9960 in)
from gudgeon pin centre to piston crown 40 mm (1.5748 in) 39.4 mm (1.5512 in)
Weight 445±3 gram
Max weight difference between pistons in same engine 6 gram
Piston float
0.090-0.110
mm (0.0035-0.0043 in)
Piston diameter, A-marked pistons
87.900-87.910
mm
(3.4606-3.4610
in)
B-marked pistons
87.910-87.920
mm
(3.4610-3.4614
in)
C-marked pistons
87.920-87.930
mm
(3.4614-3.4618
in)
Piston diameter is measured at right angles to gudgeon pin
bore and:
11 mm (0.43 in) from lower edge of piston for
B27F
1976-1978
8.5 mm (0.33 in) from lower edge of oil scraper ring for other
engines.
Diameter, gudgeon pin bore:
Marking piston Marking gudgeon pin
1 Blue 23.514-23.517 mm (0.9257-0.9259 in)
2 White 23.511-23.514 mm (0.9256-0.9257 in)
3 Red
23.508-23.511
mm (0.9255-0.9256 in)
MAHLE PISTONS (B 27)
B 27 A 1976-1979
B 27 E
1975-1978
1979-1980
B27F
1979
1976-1978
Height, overall 63,4 mm 62.2 mm 65.3 mm
(2.4960 in) (2.4488 in) (2.5709 in)
from gudgeon pin centre to piston crown 39.4 mm 38.2 mm 41.3 mm
(1.5521 in) (1.5039 in) (1.6260 in)
Weight 445±3 gram
Max weight difference between pistons in same engine 6 gram
Piston float 0.020-0.040 mm (0.0008-0.0016 in)
Piston diameter, A-marked pistons 87.970-87.980 mm (3.4634-3.4638 in)
B-marked pistons 87.980-87.990 mm (3.4638-3.4642 in)
C-marked pistons 87.990-88.000 mm (3.4642-3.4646 in)
D
-ts.
Piston diameter is measured at right-angles to gudgeon pin
bore,
8 mm (0.31 in) from bottom edge.
Diameter, gudgeon pin bore:
Marking,
piston Marking, gudgeon pin
Blue Blue 23.510
mm-23.513
mm
(0.9255-0.9257
in)
White White 23.507-23.510 mm
(0.9254-0.9255
in)
Red Red 23.504-23.507 mm (0.9253-0.9254 in)
4
Group 21 Reconditioning engine
Specifications
Pistons for B 28
Pistons and liners are matched sets.
Only
Mahle
pistons are in use.
Weight 455±3 grams
Max weight difference between pistons in same engine 6 grams
Height, overall A- and F-engines 62.8 mm (2.4724 in)
E-engine 65.3 mm (2.5709 in)
from gudgeon pin centre to piston crown
A- and F-engines 38.8 mm (1.5276 in)
E-engine 41.3 mm (1.6260 in)
Piston float
0.020-0.040
mm
(0.0007-0.0015
in)
Piston diameter, A-marked pistons 90.970-90.980 mm
(3.5814-3.5818
in)
B-marked pistons 90.980-90.990 mm (3.5818-3.5822 in)
C-marked pistons 90.990-91.000 mm (3.5822-3.5826 in)
Piston diameter is measured at right-angles to gudgeon pin
bore,
8 mm (0.31 in) from bottom edge.
Diameter, gudgeon pin bore:
Marking,
piston Marking, gudgeon pin
Blue Blue
23.510-23.513
mm (0.9255-0.9257 in)
White White 23.507-23.510 mm
(0.9254-0.9255
in)
Red Red 23.504-23.507 mm (0.9253-0.9254 in)
Piston rings
15 mm
Ring gap measured 15 mm (0.6 in) from
lower edge of cylinder
Height.
mm
in
mm
in
3)
mm
in
Upper
compression
ring
1.478-1.490
9.0582-0.0587
0.045-0.074
0.0017-0.0029
0.40-0.60
0.0157-0.0236
Lower
compression
ring
1.978-1.990
0.0779-0.0783
0.025-0.054
0.0009-0.0212
0.40-0.60
0.0157-0.0236
Oil ring
2.629-2.731
0.1035-0.1075
0.009-0.233
0.0003-0.0091
0.38-1.45
0.0150-0.0570
Side clearance (measured with ring on piston) mm
Ring gap when checked in 91 mm (3.5826 in) cylinder (B 28),
88 mm (3.4646 in) (B 27), see fig mm
Gudgeon (piston) pins
Diameter
Marking,
Marking, piston
gudgeon pin
Blue Blue (1)
23.500-23.497
mm (0.9251-0.9250 in)
White White (2) 23.497-23.494 mm (0.9250-0.9249 in)
Red Red (3) 23.494-23.491 mm (0.9249-0.9248 in)
Clearance in connecting rod 0.020-0.041 mm
(0.0007-0.0016
in)
piston,
Mahle 0.010-0.016 mm (0.0003-0.0006 in)
Demolin
0.014-0.020 mm (0.0006-0.0008 in)
Group
21
Reconditioning engine
Specifications
VALVE SYSTEM
Valve
Clearances
(varies with engine type)
Valve clearance mm (in)
Intake valves, cold engine
warm engine
Exhaust valve, cold engine
warm engine
Engine type - model year
B 27 A
1976-1979
B
28 A 1980
1981-1982
B27 E 1975-1978
1979-1980
Sweden + Australia
1979-1980
Other markets
B28 E1981-1983
B 27
F1976-1979
B 28
F1980
1981-1982
Type 1
0.10-0.15
(0.004-0.006)
0.15-0.20(0.006-0.008)
0.25-0.30
(0.010-0.012)
0.30-0.35
(0.012-0.014)
X
X
X
X
X
X
X
Type
2
0.20-0.25
(0.008-0.010)
0.25-0.30
(0.010-0.012)
0.30-0.35
(0.012-0.014)
0.35-0.40(0.014-0.016)
X
X
X
Valves mm (in)
29,5°
£
44(1.7322)
7.965-7.980
(0.3135-0.3141)
^
26.5
(1.0433)
Tapered
Intake valves
7.975-7.990
(0.3139-0.3145)
44.5'
59"
37
iT
(1.4566)
32 (1.2598)'
Exhaust valves
7.965-7.980
(0.3135-0.3141)
Valve seats mm (in)
1.7-2.1
mm (0.0669-0.0826)
1.3-1.7
mm
(0.0511-0.0669)
Intake valve seat
Early types
Intake valve seat
Late types (venturi
seat):15°
and 60° are
correct angles to reduce seat width.
2.0-2.4
mm (0.0787-0.0944)
Exhaust valve seat
Group 21 Reconditioning engine
Specifications
Note!
When replacing valve seats: the interference between
the valve seat and its bore in the cylinder head must be
0.070-0.134
mm, (0.0027-0.0052 in), i.e. the valve seat diameter must be 0.070-0.134 mm greater than the diameter of the
bore in the cylinder head.
Valve seats are available in three oversizes.
Valve guides
mm
(in)
Length 50.1-51.3 (1.2725-1.3030)
Inner
diameter
8.000-8.022
(0.3149-0.3158)
Press-in measurement to cylinder head contact surface against
block:
intake 39.5-40.5 (1.5551-1.5944)
exhaust 36.9-37.9 (1.4527-1.4921)
Valve guides are available in three oversizes, and are marked
with grooves.
Standard
Oversize 1
2
3
Marking
No groove
1 groove
2 grooves
3 grooves
Reamer for seat
5166
5167
5168
/"*
Valve
springs
Two types of valve springs are in use. The springs are colour coded
as follows:
Grey springs:
B27A
1976-1979
B27E
1975-1978
1979-1980
Sweden + Australia
B27F
1976-1979
Green springs:
B28A
1980-1982
B 27 E
1979-1980
(excluding Sweden, Australia)
B28E
B28F
1981-1982
1980-1982
Grey springs:
Length
mm
47.2
40.0
32.2
in
1.86
1.57
1.27
Load
N(kp)
0
233-268
(23.3-26.8)
521-585
(52.1-58.5)
lbs.
0
52-60
116-131
Green springs:
Length
mm
47.1
40.0
30.0
in
1.85
1.57
1.18
Load
N(kp)
0
23.0-26.6
613-689
(61.3-68.9)
lbs.
0
51-59
137-154
Group 21 Reconditioning engine
Specifications
Rocker arm mechanism
The rocker arm contact surface against the camshaft is surface-hardened and must not be ground.
Diameter, rocker arm shaft 19.959-19.980 mm
(0.7857-0.7866
in)
Hole diameter, rocker arm 19.992-20.013 mm
(0.7870-0.7879
in)
Clearance, shaft-rocker arm 0.012-0.054 mm (0.0005-0.0021 in)
TIMING GEARS
Camshaft
Three types of camshafts with different lift heights
are
in use.
The part number is marked on the front end.
Camshaft
Marking (part number), left
right.
Max. lift height, left mm
right mm
Check of camshaft setting (cold engine):
Adjust valve clearance on 1st and 6th intake valves to 0.7
mm (0,027 in), the intake valves should then open at,
1st BTDC
6th BTDC
Type 1
7910
245 522
(-143 or -144)
7910
245 412
5.144
(0.202 in)
5.059
(0.199 in)
9°±3°
7°±3°
Type
2
74
01 269138
74
01269
139
6.004
(0.236 in)
6.004
(0.236 in)
9°±3°
9°±3°
Type 3
74
01
269 615
74
01
269 616
5.96
(0.234
in)
5.96
(0.234 in)
8°±3°
8°±3°
Engine type
B27 A 1976-1979
B28
A 1980
1981-1982
B27E1975-1978
1979-1980 Sweden 4- Australia.
1979-1980
Other markets
X
X
B28E1981-1983.
B27F
1976-1979.
B28F1980
1981-1982.
Journal diameter, counting from front (all types): mm (in)
1st 40.440-40.465 (1.5921-1.5931)
2nd 41.040-41.065
(1.6157-1.6167)
3rd
41.640-41.665 (1.6393-1.6403)
4th 42.240-42.265 (1.6629-1.6639)
Radial play 0.035-0.085 (0.0013-0.0033)
End float, new 0.070-0.144 (0.0027-0.0056)
max 0.5 (0.0196)
Group 21 Reconditioning engine
Specifications
CRANK MECHANISM
Crankshaft
Max run-out (measured on two centre main bearing journals). 0.02 mm
Crankshaft, end float
0.070-0.270
mm
clearance (main bearings) 0.038-0.088 mm
Crank journals, side clearance 0.20-0.38 mm
clearance 0.030-0.080 mm
Rear sealing ring diameter, standard 79.926-80.000 mm
undersized
79.726-79.800
mm
(0.0007 in)
(0.0027-0.0106 in)
(0.0014-0.0034
in)
(0.0078-0.0149 in)
(0.0011-0.0031 in)
(3.1466-3.1496 in)
(3.1388-3.1417 in)
r
Main bearing journals
Out of roundness, max 0.007 mm
Taper, max 0.01 mm
Diameter, standard 70.043-70.062 mm
undersized
69.743-69.762
mm
Main bearing shells, thickness, standard
1.961-1.967
mm
oversized 2.111-2.117 mm
Width of crankshaft journal for thrust bearing (rear main bearing
journal):
standard
29.20-29.25
mm
oversized 1 29.40-29.45 mm
2 29.50-29.55 mm
3 29.60-29.65 mm
Thrust bearing washer, thickness, standard
2.30-2.35
mm
oversized 1
2.40-2.45
mm
2
2.45-2.50
mm
3
2.50-2.55
mm
(0.0002
in)
(0.0003
in)
(2.7575-2.7583
in)
(2.7457-2.7465
in)
(0.0772-0.0774
in)
(0.0831-0.0833
in)
(1.1496-1.
(1.1574-1.
(1.1614-1.
(1.1653-1.
(0.0905-0.
(0.0944-0.
(0.0964-0.
(0.0984-0,
1515
in)
1594
in)
1633
in)
1673
in)
0925
in)
0964
in)
0984
in)
1003
in)
Connecting rod bearing journals
Out of roundness, max 0.007 mm
Taper, max 0.01 mm
Diameter, standard 52.267-52.286 mm
undersized
51.967-51.986
mm
Connecting rod bearing shells, thickness, standard
1.842-1.848
mm
undersized
1.992-1.998
mm
Bearing journal width 39.99-40.09 mm
rr
Taper Out of roundness
(0.0002 in)
(0.0003 in)
(2.0577-2.0585 in)
(2.0456-2.0466
in)
(0.0725-0.0727 in)
(0.0784-0.0788
in)
(1.5744-1.5783 in)
Connecting rods
End float on crankshaft (both con rods fitted) 0.20-0.38 mm
Length between centres 146.15 mm
Max weight difference between con rods in same engine ±2.5 grams
(0.0078-0.0149 in)
(5.7539 in)
Flywheel
Axial throw, max 0.05 mm
Radial throw, max (measured at diameter 282.4 mm)
0.15
mm
(0.0019 in)
(0.0059 in)
Group 21
Reconditioning engine
Specifications
TIGHTENING TORQUES
The tightening torques shown below apply to oiled nuts and
bolts.
Degreased (washed) parts must be oiled prior to assembly.
Tighten all bolts in stages according to below:
1 = 10
Nm
(1
kpm =
7 ft. lbs)
2 = 30
Nm
(3 kpm = 22 ft. lbs)
3 = 60 Nm
(6
kpm - 44 ft. lbs)
4 = Wait
10-15
minutes
5 = Slacken bolts
6 =
15-20
Nm
(1.5-2.0
kpm =
11-15
ft. lbs)
7 = Angle-tighten to
113-117°
8 = Warm-up engine to operating temperature
9 = Cool block 30 minutes
10 = Slacken
and
then retighten
bolts one at a
time
in
specified
tightening order.
Retighten according to stages 6 and 7.
Tightening sequence for cylinder head bolts
#
®
o
a
!
©
©
i i
®
»
Tightening sequence for main bearings (via lower crankcase)
Main bearings
Tighten all nuts in stages:
1 = 30 Nm (22 ft. lbs)
= Slacken nut 1
= Tighten nut 1 to
30-35
Nm (22-26 ft. lbs.)
= Angle-tighten nut 1 73°-77°
=
Slacken and retighten the other nuts in the order
specified in stages 2-4.
Nm
Cylinder head (see below)
Connecting rod bearings 45-50
Crankshaft front end,
1975-1977 160-180
1978-
240-280
ft.
lbs.
33-37
118-133
177-207
40 mm = 1.575 in
45 mm = 1.772 in
1975-1977
1978-
Nm
Camshaft sprocket 70-90
Flywheel (always use new bolts) 45-50
Spark plugs (do not oil)
12±2
Valve cover
15
ft.
lbs.
52-66
33-37
9±1.5
11
10
Group
21
Reconditioning engine
Specifications
Group 22 Lubricating system
OIL PUMP
End float 0.025-0.084 mm (0.0009-0.0033 in)
Radial play between cog tip and pump housing
wall
(excl.
bearing play)
0.110-0.185
mm (0.0043-0.0072 in)
Backlash (excl. bearing play) 0.17-0.27 mm
(0.0066-0.0106
in)
Bearing play, drive shaft
0.015-0.053
mm
(0.0006-0.0021
in)
idler shaft
0.015-0.051
mm
(0.0059-0.0020
in)
Relief valve spring, length at various loads:
unloaded 89.5 mm (3.52 in)
loaded to 88.3 N (8.83 kp = 20 lbs) 56.5-60.5 mm (2.22-2.33 in)
Special tools
999
Description - use
1426-9
1801-3
2484-7
2520-8
4090-0
5029-7
Drift: fitting pilot bearing in crankshaft (late type)
Standard handle: used with 5101 and 5953
Centering drift: clutch, M45/46 gearboxes (early type)
Stand:
used with fixture 5099
Extractor: pilot bearing
Drift: fitting intake valve seat
Continued on page 12.
4090
11
Group 21 Reconditioning engine
Special tools
999
Description - use
5092-5
5093-3
5096-6
5098-2
5099-0
5101-4
5103-0
5108-9
5109-7
5111-3
5112-1
5113-9
5128-7
5129-5
5165-9
5166-7
5167-5
5168-3
5192-3
5218-6
5220-2
5224-4
5953-8
Combined tools: (6 parts)
removing-fitting
gudgeon (piston) pins
5128
and
5129
also required
for
Mahle
pistons.
Retainer: (4 x) for cylinder liners
Spacer sleeve: main bearings
Protractor: for angle-tightening cylinder head bolts and main bearing nuts
Fixture: for engine. Used with 2520
Drift: fitting pilot bearing in crankshaft (early type). Used with 1801
Drift: fitting crankshaft front oil seal
Drift: fitting valve guide - intake
Drift: fitting valve guide - exhaust
Centering drift: clutch, M45/46 gearboxes (late type)
Locking sector: locking flywheel
Centering drift: clutch, M50/51 gearboxes
Piston support: removing gudgeon pin from Mahle piston. Used with 5092
Piston support: fitting gudgeon pin in Mahle piston. Used with 5092
Reamer kit: valve guides: contains 5164 (early type), 5224 (late type), 5166, 5167 and 5168
Reamer: valve guide seat oversize 1
Reamer: valve guide seat oversize 2
Reamer: valve guide seat oversize 3
Support: for dial indicator. Measuring cylinder liner height and piston height. Also 5094 can be
used
Drift: removing valve guides. Fitting oil seal on valve guide
Drift: fitting valve seat - exhaust
Reamer: cleaning valve guides. Also 5164 can be used
Drift: fitting crankshaft rear oil
seal.
Used with 1801
(y) (§)
5128
5129
5092-1 5092-2 5092-3 5092-4 5092-5 5092-6
IIG3U
5092
5093
5099
T
MEA
!•
Wz
^Mm
A
i
1
^~-a
L„iffli
1801 + 5101
M|
1426
^tor^^^f
-•*
z^^^j
5101
Group
21
Reconditioning engine
Special tools
5103
5108,
5109
5111
r
5112
5113
n
ggg*
#i U
(y)
(g)
5128
5129
5092-1
5092-2 5092-3 5092-4 5092-5 5092-6
110 214
5128,
5129
5165
(5166.
5167,
5168)
5192
5218
5220
*i
5224
5953
13
Group
21
Reconditioning engine
Thread repairs
A. Thread repairs
A1
General
A damaged thread can usually be repaired with a thread
insert.
Thread inserts and installation tools are available
from Volvo Parts.
Note!
Some threads can/may not be repaired with
thread inserts, see next page.
A2
Installation tools
Tools to install thread repair inserts are supplied in kits.
Some thread inserts are also included in the kits. See
the table below.
Note!
Each tool can be ordered separately.
Thread
M6x1
M7x1
M
8x1.25
M 10x1.5
M
12x1.5
M
14x1.25
M
14x1.25
M
14x1.5
M
16x1.5
M
18x1.5
5/8"-
18UNF
Complete
kit
998 5840-9
998 5841-7
998 5842-5
998 5843-3
998 5844-1
998 5845-8
1
998 5846-6
998 5847-4
998 5848-2
998 5849-0
998 5850-8
Contents of complete kit
Tap A
998 5802-9
998 5806-0
998 5810-2
998 5814-4
998 5818-5
998 5823-5
998 5826-8
998
5827-6
998 5831-8
998 5833-4
998 5860-7
Tang B
998 5803-7
998 5807-8
998
5811-0
998
5815-1
998 5819-3
2)
2)
2)
2)
2)
2)
Mandrel C
998 5804-5
998 5808-6
998 5812-8
998 5816-9
998 5820-1
998 5824-3
998 5824-3
998 5828-4
3)
3)
3)
Crank D
998
5805-2
998
5809-4
998 5813-6
998 5817-7
998 5821-9
998 5825-0
998 5825-0
998 5829-2
3)
3)
3)
ToolE
4)
4)
4)
4)
4)
4)
4)
4)
998 5832-6
998 5834-2
998 5861-5
Thread inserts
(10 x) F
956014-5 +
956015-2
948015-3 +
941843-5
956018-6 +
956019-4
956022-8 +
956023-6
948094-8 +
948095-5
948756-2
948756-2
948758-8
947847-0
947843-9
948755-4
Notes:
11
Designed especially for spark plug threads (do not drill).
21
Use flat nosed pliers or similar
tool.
3)
Supplied with set.
4>
Tool 998
5830-0
is not supplied with complete kit, but may
be ordered separately.
14
Group 21 Reconditioning engine
/^-
Thread repairs
A3
Do not repair these threads
(Threads shown below cannot or must not be repaired)
for oil filter
Connecting rod bearings bolts
Cylinder block
Timing gear case
Adjustment screws
Idle
adjustment screw
Lower section of air-fuel control unit
B 27 E
1979-, B 28 E, B 27/28 F
Idle adjustment screw
Intake manifold B27/B28
All conical threads such as plugs and nipples in intake manifold (also B 28/B 28 A)
75
Group
21
Reconditioning engine
Thread repairs
A4
Thread repair insert,
drill diameter
0
Thread Length mm
M
6x1
9.0
12.0
M7x1
10.5
14.0
M 8x1.25 8.0
11.4
16.0
M
10x1.5 10.0
15.0
20.0
25.0
M
12x1.5 12.0
24.0
30.0
M 14x1.25 14.5
M 14x1.5
10.0
M
16x1.5 12.0
Mx18x1.5 13.5
5/88"x18UNF
8.0
P/N
956014-5
956015-2
948015-3
941843-5
956017-8
956018-6
956019-4
956021-0
956022-8
956023-6
956024-4
948094-8
948095-5
956028-5
948756-2
948758-8
947847-0
947843-9
948755-4
Drill dia mm
6.3
6.3
7.3
7.3
8.4
8.4
8.4
10.5
10.5
10.5
10.5
12.5
12.5
12.5
14.3
14.5
16.5
18.5
16.4
16
Combination tap
Tap section
Reamer section
Guide
A5
Repairing spark plug threads
Cylinder head must be removed first. Tap hole from inside to avoid damaging seat for spark
plug.
Do not drill the hole. Use tap 998 5823-5.
Re-cut old threads only. Do not cut further into
cylinder head. Spark plug bore must not be threaded
along entire length.
Screw in thread insert (P/N 948756-2).
Group
21
Reconditioning engine
Thread repairs
Installing thread inserts
Thread
Thread depth
Drilling depth
A6
Drilling depth
Select drill size, tap and insert
Measure length and thread of old hole.
A7
Tap hole
NOTE!
Special instructions for spark plug holes, see
page 16.
Measure depth of hole. Drill out hole to this depth.
Cut the screw thread to such a depth that the thread
insert makes contact with fully cut screw thread along
its entire length.
Clean the hole.
A8
Assemble installation tool
M6-M14 threads: fit correct mandrel and crank in in-
stallation tool 998 5830-0.
M16 and coarser threads: use the prescribed complete
installation
tool.
17
Group 27 Reconditioning engine
Thread repairs
Tang
Mandrel
Crank
A9
Fit thread insert in installation tool
Fit the thread insert in the tool with the tang facing
downwards.
Turn the crank clockwise until the tang of the thread
insert engages the slot in the crank.
Without pressing, screw the thread insert into the
mandrel until the first thread of the insert is flush with
the opening of the mandrel.
AW
Install thread insert
Hold the tool vertically above the centre of the hole.
Without pressing, screw in the thread insert until the
top thread of the insert is at least 1/2 a thread below the
working surface (0.5 x pitch). The insert must not be
screwed in to the bottom otherwise it will not be possible to break off the tang.
AH
Break off tang
M16-M12
threads:
use the tang breaker in the installa-
tion kit.
M14 and
coarser
threads:
use a pair of
flat nosed pliers
to break off the tang downwards.
Remove the tang from the hole.
18
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