Torque Specifications
Teledyne Continental Motors, Inc.
TM
B-8
IOF-550 Permold Series Engine Maintenance Manual
1 April 2007
Table B-4.
Component Specific Torque Specifications
Torque Value
SIZE
FASTENER
IN./LB.
FT/LB.
MODELS AFFECTED
Crankcase
.31 - 18
Bolt- Oil sump flange
155-175
12.9-14.6
IO-346, O-470, IO-470, GIO-470,
TSIO-470, IO-520, L&TSIO-520,
GTSIO-520, IOF-550, IO-550, TSIO-
550, TSIOL-550, TSIOF-550
.31 - 24
Nut- Crankcase Flange
180-220
15.0-18.3
IO-346, O-470(AR), IO-470, GIO-470,
TSIO-470, IO-520, L&TSIO-520,
GTSIO-520, IO-550, IOF-550, TSIO-
550, TSIOF-550, TSIOL-550
.31 - 24
Nut-Crankcase flange
(Stainless Steel Only)
240-280
20.0-23.3
(AR) Stainless Steel Hardware Only
.31 - 24
Nut-Magneto Flange
100-120
8.3-10.0
All Engine Models
.38 - 24
Nut-Crankcase tie bolts
370-390
30.8-32.5
All models (AR) EXCEPT 360's & IO-
240 and IOF240
.38-24 Nut-Mounting
brackets
to
crankcase
275-325 22.9-27.1 All
models(AR)
.38-24
Nut-Through bolt, upper rear 275-325
22.9-27.1
All 470's, All 520's, All 550's
.44-20
Nut-Cyl. to crankcase
studs.(includes 7th stud)
490-510
40.8-42.5
All models (except TSIOL-550)
.44-20
Nut-Through bolts at
cadmium plated washer
440-460
36.6-38.3
All models (AR)
.44-20
Nut-Crankcase tie bolts-
nose & below camshaft
440-460 36.6-38.3 All
models(AR)
.44-20
Nut-Through bolt at cylinder
flange
490-510
40.8-42.5
All models (AR) EXCEPT 360's, IO-
240, IOF-240
.44-20
Nut-Through bolt at front
mount belt-driven alternator
mount.
490-510
40.8-42.5
All models (AR) with front mount belt-
driven alternators
.50-20
Nut-Through bolt at cad
plated washer.
615-635
51.2-52.9
IO-346, O-470, IO-470 TSIO-470, IO-
520, L/TSIO-520 GTSIO-520, IO-550,
IOF-550, TSIO-550, TSIOF-550, GIO-
470
.50-20
Nut-6 Point-Through bolt at
cylinder flange
(P/N 634505 .33 in. high)
690-710
57.5-59.2
IO-346, All 470, 520, 550, (Except
TSIOL-550)
.50-20
Nut-12 Point-Thru bolt at
cylinder flange
(P/N 652541)
790-810
65.8-67.5
IO-346, All 470, 520 & 550
.50-20
Nut-Crankcase tie bolts-
nose
640-660 53.3-55.0 All
models(AR)
.62-18
Plug-(using crush washer)
190-210
15.8-17.5
All models(AR)