What's the worst damage you have seen to a drivetrain?

Clutch was shot. Discs were warped about 3" each and intermediate plate was cracked. Cause was stupidity.

Another time I found some chewed up snap rings on the magnets when I had a PTO off. Boss said send it. Slapped repaired PTO back on. Backed it out the door and it was sticking in gear. Told boss the transmission needs to come out. Boss put it to work. 2 hours later the lower countershaft decided to eject itself through the case and onto the highway.

 

Twin screw: Inter axle driveshaft forward u-joint came apart. Driveshaft jammed into roadway took out rear axle housing. Busting rear u-joint the shaft then totaled the car following to close to react.

Single axle: had a u-joint replaced. Shop didn't grease the joint. 1,500 miles later pulling an oversize load. The u-joint came apart, damaged transmission, rush hour in the twin cities I694. Blocking right shoulder and slow lane of traffic.

 

I've seen a driveshaft twisted into two pieces. More recently, the input shaft bearing on my 13spd decided it didn't want to be part of the family anymore.

 

This doofus is your boss?
Craptastic boss.

 

Watched a super trucker try to start from a complete stop, on a minor hill, twist the driveshaft like a pretzel in a Peterbilt.
Before you ask, he was caucasian, fat, wore jeans, and boots.

 

Guy I used to work with used to be a asst. manager at a truck repair. Guy comes in, says an awful shaking,,,"bring 'er in", he said. Crawls under, the driveshaft was "cork screwed" like a drill bit. How it moved at all was the miracle.
Another one, when I worked at the asphalt company, had all Macks, guy stops on the scale loaded, gets his ticket, puts in 1st nothing, reverse, nothing. They towed the truck, turns out, the crankshaft broke right before the flywheel. Engaging a power divider while spinning always creates work for the garage,,,

 

5 or 6 years ago got a service call to one of the local LTL Carriers. Line haul truck coming out of the gate, foot slipped off the clutch. All three sections of driveshaft were on the ground, front held only by the carrier bearing.

Last year a customers 18 in Texas. Driver pulled up to a stop light. Eased out on the clutch and the stick went through the floor. Tranny had got into two gears at once. Usually that just twists the mainshaft and kills the engine. Never seen it before, but this transmission broke the flywheel housing off of the back of the engine, and spun the trans 3 or 4 times before he got it shut off.

Tearing up all kinds of stuff in the process.

 

This was over a decade ago and my foot was already out the door at that point. They had about 700 units total and went bankrupt shortly after I left.

Ironically enough I moved halfway across the province last year and the company next door to where I work owns about 30 of their old trucks.

 

My latest adventure.......it cost the original 'repair' facility right at $11,000. Just got the check yesterday.