Big Radiator Fan "HUB"

[JIM CHALOUPKA]

Has anyone worked on/rebuilt or replaced the fan clutch and shaft bearings on a series 60 engine.

I was checking things out this AM and since the air was down and the belt loose, I took it off and examined it with a magnifying glass and decided it needed replacing (small cracks and becoming brittle and worn). Checked out all the other belts and they are also being replaced.

The pulleys all look fine, wear wise and in alignment.

The idler pulleys spun freely, smoothly and true.

Spinning the fan pulley, well not so good, I am thinking, but don't really know. There is a certain roughness to the touch when spinning the shaft. Could this be caused by the clutch. There doesn't appear to be any lube fitting.

When the engine is running there is no (bad ) sound from the shaft. I listened to it with an electronic stethoscope and also felt nothing (bad) with a finger on the shaft end.

Maybe I am catching this just in time?
Maybe there is nothing wrong?
Any ideas anyone.

Also does anyone know will the fan and clutch shaft come off as an assembly without removing the radiator shroud?

JIM

[JIM CHALOUPKA]

I talked to Dave, a technical assistant at Prevost emergency service 1- 800-463-7738.
He offered the term growling to describe what I am experiencing in the fan shaft and said I am probably experiencing the preliminaries to failure. The shaft should turn smoothly.
He also said that to replace the entire unit assembly was the better way to go as a press and special pullers were necessary to rebuild the old unit.
When asked if the unit could be changed without removal of any other components, he said yes. First remove the fan from the unit by taking out the 4/5 mounting bolts and move it forward into the shroud and out of the way, then remove the clutch/shaft unit, add the old pully and reinstall all components removed.

Parts dept is closed today. I will order Mon and post back how the job goes.
It sounds like you could do this job by the side of the road, if you had the new parts. If your mileage is close to mine, check yours out, it's not difficult.

Feels funny talking to myself, but I guess there is someone out there

JIM

[ajducote]

JIM,
You are not talking to yourself. The information is very welcome and please keep us posted on the price and the steps needed to replace it. Pictures are good....

[Kevin Erion]

I changed mine at about 112000, it was sounding bad! I have a feeling this is a common part to fail, and not very cheap!

[dreamchasers]

Jim,

After reading your post, I went out and checked mine. All OK.

I do appreciate all the details.

Hector

[PLSNTVLE2]

JC
Great post. I'll bet a lot of people don't think of checking the fan clutch as a maintainance item.
I twirl mine around once in a while. I guess it looks cool.

I know I wouldn't want my fan to fly off while crossing the desert.
Thanks for bringing it to mind.

[Jon Wehrenberg]

It is difficult to hear bearings going bad when the engine is running.

Jim is directly on target describing how he took the opportunity to do a little inspection work and find minor issues like the belt and the shaft bearing. By dealing with them now they are non-issues. Had he learned of the problem when the belt broke or the bearings seized it would have been more serious and he may have been facing a tow or a roadside repair.

There are several idler pulleys and belts that should be periodically checked. Not all coaches are the same because of the variety of alternator and AC configurations so there is not likely any specific advise that applies to all.

[JIM CHALOUPKA]

The fan clutch assembly Pt No 550634 new No (550837) ordered today @ $1108.95 ea.

JIM

[Joe Cannarozzi]

Do they have a rebuild kit for that?

[JIM CHALOUPKA]

I asked that very question of the parts guy, Tom, and he said no not as such, no kit. What you do is look at the blow out diagram in the parts CD or on line or in a hard copy of the Prevost parts book and pick out the parts pieces you want.
I asked do you sell many parts pieces for rebuild and his answer was "NO, when that unit goes it usually means the bus is down, by the side of the road or in the garage and the main objective is to get it up and running in the shortest time." He further acknowledged that a press and special tools were necessary for a rebuild. Tom said some customers rebuild units and keep them on the shelf for future need. He implied that this clutch assembly had a high sales volume and is a very profitable maintenance item for his Co..

All you guys better check your units and save yourself a breakdown.

JIM