You are here:

Truck Repair/accessory drive n14


QUESTION: what would cause the accessory drive shaft to break off right behind the pulleys

ANSWER: Could be a number of things I guess. Could have been cracked and the belts pulling against it caused it to break off the bearing in there could have been getting hot and weaken it. Just be sure when you go to replace all that its put in time.

---------- FOLLOW-UP ----------

QUESTION: could a bad vibration dampner break it?

ANSWER: I don't think so but if you suspect it being bad I would definitely change it can bend or break the crankshaft.

---------- FOLLOW-UP ----------

QUESTION: thanks, i just had this motor put in, it was a used motor, the seal was leaking around the shaft after they installed the motor and they said they would fix it this spring, taht was 2 months ago, now they are telling me the only thing that could of caused it is the vibration dampner, i had my doubts, so i suspect they are tring to get out of replacing it for free, thank you so much for the answer!

For that shaft to break because of the dampner the vibration would have to travel up through the gears off the crankshaft and through the gear on the cam to the accessory drive gear.  Not saying it couldn't happen but ive never heard of that causing it.

Truck Repair

All Answers

Ask Experts


Jeff Drumm


I Can answer any question pertaining to semi trucks and trailers. Have no experience in the automotive field so not able to help in that area.


My experiences in Semi Trucks is. I own my own truck and i presntly maintain a 80 truck fleet. Can handle any questions pertaining to a truck have tore apart and rebuilt every aspect on them. Fleet I deal with is Mainly Volvo trucks and a handful of freightliners. Work on automated transmissions on a daily basis along with carrier apu's. With engines my specialty is the 60 series Detroit but do work on the cummins isx the n-14 and the ism. and also the Volvo engines.

Have a College Degree from university of northwestern ohio in diesel and agriculture mechanics. Have 10 years behind the wheel driving a truck and 4 years working on trucks full time. Also have grown up on a farm so have been tinkering on trucks and tractors all my life.

Awards and Honors
I've gone through online schooling and have received certificates from webb wheel, Timken and Volvo academy.

©2016 All rights reserved.