SCREEN GP-MAGNETIC 9M8669 - Caterpillar

The FT1486 Chain Assembly can be used to lock up failed front power takeoff clutches on 3408 and 3412 Marine Engines if there is no other way to power the winch to get fishing nets in. This tool will give assistance to a failed clutch or one that slips when under a load; it must be used for temporary, emergency purposes only.
The FT1486 Chain Assembly (shown in Illustration 1) is fabricated from 0.375" × 1.250" (9.5 mm × 31.75 mm) mild steel, flat stock and .312" (7.9 mm) chain and hammerlocks, which can operate with a load of 4100 pounds (1864 kg). Drawings of this chain assembly are available from your Division Service Manager.
Illustration 1.Use the steps that follow to install the FT1486 Chain Assembly.
1. Stop the engine, block the load on the winch, and remove the inspection cover from the clutch housing.2. Turn the clutch until one of the three levers is in the position shown. Remove the cotter, pin and two washers (Illustration 2).
Illustration 2.
Illustration 3.
Illustration 4.3. Install bolt, washers, nut and the 90° angle bracket of the chain (Illustration 3).4. Turn the clutch in the opposite direction of the engine rotation approximately 1 1/4 revolutions.5. Remove one of the bolts from the drive ring and fasten the 30° angle bracket of the chain assembly to the drive ring with the correct bolt and washer. Single plate clutches use S1590 Bolt while double plate clutches use S1619 Bolts (Illustration 4).6. Turn the clutch in the opposite direction of engine rotation until all the slack in the chain has been removed and engage the clutch. Reinstall the inspection cover on the opening of the clutch housing.
This tool must not be used for permanent duty. The chain assembly must be removed as soon as the fishing nets are in. Constant use of this tool can cause damage to drive components.
The FT1486 Chain Assembly can be used on 3N7840, 3N7843, 5N1729, 5N1730, 5N2851, 5N2853, 5N4155, and 5N4156 Clutch Groups for 3408 and 3412 Marine Engines.