Eagles International Forum

David Anderson posted on BCM about his trials and tribulations of removing the large 3 groove pulley.  I started this thread so that we will have documentation in our tech archives.  David, if possible I would love to have you post the pictures you did over there so we can build on this thread.

The issue is that the pulley is mounted with what is called a Taper Lock bushing.  I have worked with them all my years at Gates and now teach about their installation/remove in my "teaching" gig.  If you have never worked with them, it is not obvious how they work.

Hopefully David will post the pictures and we can discuss in more detail.

David, I have the pulley and complete bearing housing.  It is yours for the cost of shipping ($$$$).

Jim

Ok, Jim, be glad to share

I called San Antonio Belt and Pulley and sent them pictures.
After studying this, they told me to tap the outer pulley toward the inside and it will slide off the bushing, but the whole assembly comes off at the same time.
So I did that and it slid right off.  I took a small chisel and spread the bushing and it broke in half, but it can still be reused that way.  The 3 pieces all came off together.

Note:  I did have to torch heat the pulley around the allen screws to get them loose.  

There are lots of videos on u tube on removing Taper lock bushings.  Here is the one I watched:
https://www.youtube.com/watch?v=RBjtuetw44Q

If I would have done that first I wouldn't have broken mine.
 

I welded the broken piece back on and put the whole assembly back on the shaft.  I think I am good to go. 

Jim, I have a 6k mile trip coming up.  If my repair fails I will call you 911.
David

David, thanks for posting your pictures and the video link.

The video link is pretty darn good at explaining how to install and remove the bushing.  There should only be two screws that drive the busing into the pulley. You would not believe how many installations I have looked at that had all three holes filled with Allen head set screws. Mechanics just do not feel comfortable having an empty hole .    The so called set screws are not the normal variety,  but rather have a rounded bottom that mates with the bushing.  If a normal set screw is used, it is not the end of the world.

An interesting factoid:  the set screws are not there to transmit the torque.  I have been at the Dodge Industrial Power Transmission plant (link)  when they were doing some testing for Gates and the tests were run after the screws were removed.  The taper in the system does an amazing job of transmitting the torque.

The other major bushing system out there is called Quick Detach (or QD).  It uses similar technology but looks quite different.

I have seen QD bushings used after they were broken in two, but don't recall seeing Taper Lock bushings used after they were broken in two.

When you install the bushing, make sure the taper surfaces are clean (no lube) and alternate between tightening the setscrews and tapping the bushing halves with a hammer.   Torque the set screws a little at a time (back and forth between the two) with a light tap each "half" every now and then.

I suspect your weld repair will work just fine.  Had to do that on an IHC engine.

Jim

I deal with lots of that sort of stuff for work and it’s all qd.

So that’s what I have on my bus. Not sure the benefits exactly but I do think it’s easier to reset

Mason, the Taper Lock and QD bushings are used to mount belt pulleys, chain sprockets and a host of other power transmission components.  They are the major players in the market.  The choice is often what the customer wants (at least for belts since belt pulleys are offered with both systems).  In the case of chain sprockets the market is kind of tilted towards Taper Lock since it is a more "compact" system. 

Another interesting factoid (?):  I used QD bushings for my fan drive system including a QD busing that had bearings in it for my idler.  QD bushings typically use 3 bolts to draw the bushing into the pulley.  They have two threaded holes to remove the pulley.  I had to do some maintenance on the system a few years after I installed the pulleys and found out that the tapped holes in the bushing (for removal) had badly corroded due to the harsh environment at the rear of the bus.  I was not at the shop and had a heck of a time getting the bolts to thread into the hole.  Upon installation I installed bolts in the removal holes as well to protect the thread.  I cringed when I did that, as I had "lectured" many customers that those holes should be left unused :D :o

Jim