SUPPORT AS 2806935 - Caterpillar

A 9U7224 Manifold Installation Guide is available to align the manifold studs in the center of the slotted and oversize holes during installation of the exhaust manifold group. Since each flange has slotted and oversize holes, a 9U7224 Installation Guide is required for each manifold section. The installation guide is slid over a stud and into the upper 15.0 mm (.59 in.) oversize holes in each manifold section. The spacers, washers and nuts can then be installed on the other nine studs and loosely tightened to hold the manifold group in place. The installation guides can then be removed and the remainder of the spacers, washers and nuts installed.
It is recommended that the 9U7224 Installation Guides be used at the upper oversize holes at locations 11, 7 and 9 as indicated on the Exhaust Manifold Nut Tightening Sequence Illustration that follows. If the guides can not be used at location 11 or 9 because of a clearance problem at the cab or temperature regulator housing, they can be installed at locations 12 and 10.
Exhaust Manifold Nut Tightening SequenceA new nut tightening sequence is required with the new exhaust manifolds. Tighten the nuts, in the sequence shown, to a torque of 38 5 N m (28 4 lb ft).
This nut torque has been used in production since February 1992 and can be used with all 3400 Engine exhaust manifold groups. Use 5P3931 Anti-Seize Compound on the studs. New 2N2766 Lock Nuts should always be used. Do NOT use an impact wrench to run the nuts down, the threads will be galled. This can cause false torque readings when the nuts are tightened.When assembling the manifold sections, make sure that the male end of the manifold end sections is clean, dry, and free of grease or oil. Apply a thin uniform coat of 2P2333 Manifold Sealer to the male end of the end sections. Apply a thin coat of engine oil to the female ends of the manifold center section. After installing the assembled exhaust manifold group on the engine, allow the manifold sealer to cure thoroughly (overnight if possible) before starting the engine.
If a previous end or center section is damaged beyond repair, the new manifold sections are interchangeable. When replacing a previous manifold section make sure to use the equivalent new part as indicated in the above charts.