Replacing his motor mounts did not cure the chatter, in only dampened it so that it is no longer noticable.

Have a great day,

I pose a question to the 617 converts. How long will a clutch last with the higher off-idle torque the 617 can dish out? I know the clutch will do fine as far as being able to handle the output the 617 can throw at it.

Also, concerning clutch life in the MB. Is it better to start in 1st or 2nd? I figure 10mph is redline so it would have little use outside of slow traffic or burnouts...

My last question. What brand clutch do most of you use? MB/OEM, LUK, HY-TEST, or other. I'm leaning twards LUK myself.

I know it all depends on driver skill. The transport company I work for has a driver that has gone through 2 clutches, one transmission (Melted the gears), shattered an inter-axle differential, and worn down one set of spyder gears in the front axle. All in 8 months. Why he still drives here, I don't know.

Clutch and manual transmission life are 99.9% in the hands of the driver. Even with a small clutch that is used in application with more torque and HP for which it was designed, if it is driven properly will last a LONG time. If it is "hot rodded" or driven by a poorly skilled stick shift driver, it's life can be measured in minutes.

I can't believe you are asking whether you should start in first or second. This is not your Grand Dad's hay truck with a granny gear transmission. What makes this question so out of place is the fact that it is in the same post as a question about clutch life.

Lastly, the driver that is tearing up clutches and transmissions in most trucking companies that is otherwise a good emplyee is usually put in a Mack.

Have a great day,

You seem to be confused as to the function and wear characteristics of the clutch.

Neither the 616 or the 617 puts out much torque at idle.

A clutch does not wear based upon the idle engine output torque. The clutch is simply matching the speed of the vehicle with the speed of the engine. The wear on the clutch is based upon the differential of speed and the time of engagement. If you wanted the least possible wear, you would let the clutch out as fast as possible and open the rack just enough to keep the engine at idle.

Your question of additional torque is based upon the maximum output of the engine and whether the clutch is strong enough to transmit this torque without slippage in the clutch plates. On a very powerful engine, you might be familiar with the Arnold Schwarzenegger left leg that is necessary to depress the clutch. The springs are very powerful to keep the clutch plates engaged.

Naturally, it's best to start in first, because you can match the engine speed to the vehicle speed with the least clutch slippage. If you start in second, the slippage must, by definition, occur over a longer period to bring the vehicle up to a higher road speed at idle. This simply puts additional wear on the clutch linings.