There are lots of information on the internet and in service manuals about the IDI torque specs. When I rebuilt my engine in 2018, I thought of a more graphical way of representing the torque, bolt sizes, and bolt threads. This is good information if you lost a bolt, mixed up some, were looking for a replacement, or wanted to know some of the details about a part of the engine without scouring an esoteric service manual or grainy picture on the web.
Table of Contents: (click to jump to the section below)
1.) Standard Torque Chart
2.) Thread Preparation
3.) 6.9 & 7.3 IDI Front (Cover) Plate and Water Pump Bolt Torque, Size, and Thread Identification
4.) 7.3 IDI Head Bolt and Stud Torque Sequencing
5.) 7.3 IDI Bottom of Engine Related Torque Specs
6.) 7.3 IDI (and some 6.9) Top-of-Cylinder-Head Torques and Sequences
7.) 6.9 & 7.3 IDI Intake & IP Gearhouse Torque Specs and Sequencing.
8.) Various Driver Side Engine Torque Specs: (Oil Cooler, etc)
9.) Various Passenger Side Engine Torque Specs:
10.) Miscellaneous Torques:
11.) Oil Pump Bolt Information:
12.) Oil Cooler Assembly Bolt Information: (Truck)
13.) Oil Cooler Assembly Bolt Information: (Van)
14.) Oddly-Named Torques:
Standard Torque Explanation:
First off, if you don’t already know, there is a baseline torque convention called the “Standard Torque.” For a typical metal thread, there is a corresponding torque limitation. This applies for general steel bolts and nuts, but many other metals and grades of steel require a higher or lower torque spec. Never assume the torque is “standard.” Always verify before torquing down. To determine the thread size, use this kind of tool. The Standard Torque Chart is:
|Thread Size||Corresponding Standard Torque|
Second, ALWAYS CHASE your threads prior to any engine reassembly. Do not use a short cut like a tap-and-die set. It could damage the block. Also, for major fasteners like crank main bolts and head studs, use ARP fastener lube to ensure precise torque measurement.
6.9 & 7.3 IDI Front (Cover) Plate and Water Pump Bolt Torque, Size, and Thread Identification:
All front (and rear) plate torques are standard torque for 5/16″-18, which corresponds to 14 ft-lbs.
7.3 IDI Head Bolt and Stud Torque Sequencing.
The 6.9 head bolt and stud has a 7/16″ bolt diameter with 14 threads per inch. The 7.3 bolt/stud has 1/2″-13 threads.
7.3 IDI Bottom of Engine Related Torque Specs:
The following image explains all the oil-pan, oil-pump, crankshaft main, and rod cap bolt dimensions and torques.
7.3 IDI (and some 6.9) Top-of-Cylinder-Head Torques and Sequences:
For the most part, the image below works for 7.3 and 6.9, but some engines have a slightly different rocker arm (aka Valve Lever) retainer setup, but I think the torques for them are the same regardless.
Various Passenger Side Torque Specs:
Miscellaneous torques: (Taken from the Official Ford “1988-1993 Engine Service Manual, Supplement 7.3 Liter Diesel Engine” and the Official Ford “1988 Truck Shop Manual, Vol. A, Bronco, Econoline, F150-350, Superduty.”)
|Type||Max Torque||Bolt/Nut Size||Qty|
|Crankshaft Harmonic Balancer Retaining Bolt||90 ft-lbs||5/8″-11||1|
|Camshaft Screw||15 ft-lbs|
|Torque Converter Nuts (C6)||3/8″-16||4|
|Air Cleaner Stud Adapter (loctite)||45 ft-lbs||1|
|Flywheel Mounting bolt (loctite)||47 ft-lbs||3/8″-16 1-3/4″||9|
|Oil Pan Drain Plug||28 ft-lbs||1|
|T-stat Housing Bolts||20 ft-lbs||2|
|IP Gearhousing bolts (apply RTV)||14 ft-lbs||3/8″-16, (2) 4″ & (2) 1-3/4″||4|
|IP Gear-to-IP-Shaft bolts (12-pt head)||25 ft-lbs||(3) 12-pt 5/16″-24, 3/4″||3|
|IP Pipe Nut||22 ft-lbs||9/16″ hex 3/8″-16||3|
|VRV-to-IP Mounting Screws||75-90 in-lbs (8-10.5 N-m)||2|
|Type||Max Torque||Thread Size||Qty|
|Pump mounting bolts (to block)||14 ft-lbs||5/16″-18 x 1-1/2″||3|
|Pump pickup tube bolts||14 ft-lbs||Upper: 5/16″-18 x 2″
Lower: 5/16″-18 x 1 1/2″
- Front Engine Mounting bolt: 70 ft-lbs, 1/2″-13 3/4″ long and 1-1/4″ long
- “Water Outlet Elbow Mounting Bolt” (aka t-stat housing bolts): 20 ft-lbs
- “Valve Lever” (aka rocker arms) retaining bolts: 20 ft-lbs
- Heater Hose Outlet Bib (in Cylinder Head Port): 1/2″ NPT, 12-18 ft-lbs
- Valley Pan Drain Plug (never-seize): 40 ft-lbs
- Coolant Block Plugs (apply RTV): 1/2″ NPT, 25-35 ft-lbs
- Coolant Temp Sensor Switch: Unknown
- Coolant Temp Sensor: Unknown
- Cylinder head plugs: Unknown
- Oil cooler oil outlet plug: Unknown
- Oil turbo outlet on the block: Unknown
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