Drive shaft broken into two pieces while stopped at a stop sign.

By the way guys you don't have to thank me for my free advice , I know my ####...

 

Rolling backwards and catching with the clutch loaded would be my guess.

 

The stupid gear ratio is what caused it, puts lot stress on driveline when you down speed them. How downspeeding can destroy your driveline - Truck News

 

Hi Jag.s, , we're just messin' witch' ya. Everybody here has had some kind of weird failure, we know it's not your fault. "Gremlins in the machine", as I was told. Driveshafts take a beating, it's the weakest link in the drivetrain, so no worries. Just be glad it didn't take out the underside at 60 mph. If there ever was an accurate saying in trucking, it's "$hite happens" or like my farmer friends always said, if it isn't broke, you aren't using it.. Good luck, on to the next adventure.

 

Oh no. Alot of dealers are ordering the Ishift with those aggressive RAR's. Downspeeding is all the rage in the Volvo world.

 

Driving easy is good, but in first you have the most torque by far. You're more likely to over torque in first than 2nd.

 

In theory, yes there's more torque multiplication in 1st than 2nd.

In reality, the engine doesn't need to produce much torque to get rolling in first at idle. Stick the transmission in 3rd or 4th and mash on the throttle to get moving. Guarenteed there's more stress on the drivetrain that way. That's how you end up throwing driveshafts, peeling off pinion teeth or twisting input or mainshafts in the transmission.

 

I remember long ago I was picking up some parts at a local driveline shop. There was an old farmer talking with the counter guy. He had a road tractor he was using in the fields and was complaining that it was the third time the main driveshaft had twisted off. He asked......" cant you make this shaft stronger so it wont break?" The counter man answered- sure I can.......but do you really want me too?

I was young and dumb then, but I always remembered that conversation and why it made sense.