When to Change Belt Tensioner and Pulleys?

Sometimes a bad pulley will "ruin" the belt.Basically you usually have advance warning.If you hear "noise on front of motor" and track it down to bad pulley bearing . Often if you have too much slack in belt "tensioner spring is getting weak".You can also watch the whole assembly from the side ( noticing belt not straight going towards radiator and back towards firewall slightly.See "shiny spots on pulleys to where its been drifting.My tensioner was wore and "canted to left" making clicking.

 

Most likely your vibration dampener is bad

 

It’s the bracket. Gets loose breaks bolts and belt gets misaligned. But I’m sure the vibration damper is also overdue and makes problem worse.Old Truck needs a lot. But always makes the trip.

 

Most common reason for breaking bolts and brackets on accessories is vibration dampener .. it also affects clutch life in some cases which I didn’t believe but was proven to me years ago when a 98 I drove had those issues steady

 

Even when new they were a problem. Freightliner had an upgrade that included drilling out bracket and sleeves Dealer in Jackson Ms did all KLLMs Freightliners way back when

 

I would say at this time just as a PM inspect your belts for fraying or separating or anything that seems out of the ordinary belts are not much but when you do be sure to change your tensioner at the same time. to change the tensioner you will need a 1/2 ratchet a 16mm socket and a pry bar might help. be sure to keep your old tensioner for the core and check idler and other pulleys are spinning freely. to answer your question there is a gauge you can use also if there is any doubt change them before you're on the road broken down needing belts or keep the tools and belts under your bunk to replace them when they break. a bad bearing in a pulley will create a buzzing like noise

 

The problem with them is the pulley faces wear on a slope to one side and then the belt just walks off.
I've replaced mine twice on the 2013 DD15 that has 320,000 KM (dump truck) They are $800 here.

First they start chirping when cold, then chirping more, then they chew the belt, then eventually the belt just walks off.

 

And even when it is minus 40 out in the winter.....when these Detroits lose the belt, you have about 5 minutes before the warning lights and buzzer come on and then they shut off.
They don't take long to heat up.

 

Unfortunately when it heats up is the first indication you have that the belt has jumped off.

 

wanted to know if you recommend the Gates tensioner VS the dealer version...???