1982/10/27 Caterpillar

It is difficult in some applications to assemble and install the 6V3100 Timing Indicator Group. The service information which follows will permit servicemen to assemble and install the instrument more easily.

Fuel Line Wrench For 3208 Engines

Because of its location, it is difficult to tighten the 5P7437 Nut (split nut) on the No. 1 fuel injection line at the fuel injection pump. The nut can easily be installed if the serviceman first fabricates a wrench.

To make the wrench, grind or saw a 5P331 Crowfoot Wrench to the dimensions shown in Illustration 1. Remove the roll pin and the crowfoot wrench from a 5P5195 Fuel Line Wrench, and install the 5P331 Crowfoot Wrench. Fasten the wrench to the handle with the roll pin.

Adjustment Of The 6V2197 Transducer

The 6V2197 Transducer must be installed approximately 0.5 mm to 2.0 mm (.02 " to .08") from the face of the flywheel or gear to operate correctly.

If it is too close, it will not send an acceptable electrical signal to the indicator group. For example, a transducer installed too close to the camshaft drive gear on a 3208 Engine will read the rough surface of the gear instead of the timing hole. The timing indication can be constant and acceptable at low idle, but as the engine rpm is increased, it will rapidly change and will not be acceptable. The chart which follows shows typical indications from the 6V3100 Timing Indicator Group when the transducer is at different distances from the flywheel or gear.

It is difficult to correctly install the transducer by feel, but a 2D6392 O-ring Seal makes it easier to find the correct distance. To do this, slide the seal on the transducer and install transducer in the transducer adapter until it makes contact with the flywheel or gear. Push the O-ring against the adapter face. Slowly pull the transducer back from the flywheel or gear; the distance between the O-ring and the adapter is the same as the distance between the transducer and the flywheel or the gear.

Dimensions for modification of the 5P331 Crowfoot Wrench.

Timing Indication Is Constant But Retarded At Constant Speed

It is possible for the indication to be constant but retarded (less than expected). If this condition is present, the electrical signal was probably read from a hole other than the timing hole in the flywheel. This condition is generally found when Caterpillar Engines are used with transmissions from a different source in an Original Equipment Manufacturer's (OEM) product. The reason for this is special flywheels are used to connect the engines to the transmissions, and these flywheels generally have several holes in them. For example, when Caterpillar 3406 and 3408 Engines are used with Allison CT700, HT700, 5000 or 6000 Transmissions, the indications can be approximately 7.6 ° off or 22.4° off. See the article, "Indications From 6V3100 Timing Indicator Group Must Be Corrected For Some Applications, " in this Truck Engine News.

It also is possible for the balance holes on the 9N2082 Flywheel Assembly used with 3306 Truck Engines to cause problems with the TDC signal from the transducer.

Quick Test For The 6V2197 Transducer

The transducer and the signal cable can easily be tested through the procedure which follows.

With the 6V3100 Timing Indicator ready to operate, turn on the instrument and hold the tip of the transducer against the flywheel housing or engine block. Look at the "NO TDC SIGNAL" lamp and rapidly pull the transducer away from housing or block. If the lamp turns off for approximately 0.5 seconds, the transducer and the cable are good.

The use of the above information will permit servicemen to assemble and install the 6V3100 Timing Indicator Group more easily during engine service. As a result, the information is the solution to some of the difficulties that servicemen have had with the instrument.