Help, Stranded in Vegas. Alternator pully no longer connected to motor

[luvrbus]

I spoke with Bill at WW Williams the pulley is a DD part he cannot find one in the DD system it has been obsolete for 15 years from a dealer

good luck

[Van]

I was over to B&B Coach today and Gary had this in the shop. Any parts on this 871 that Randy might be able to use?

[luvrbus]

Van, that 8v71 is from a Eagle I see the mitre box drive MCI gets off the wall on the rear nothing there that would help Randy

[Ralph7]

  If Sam does not have one Lied (717-776-7725) may hay one.   There is one in my shop in Pa. but I will not be there till next fall. Check with Luke?
Are we looking 4 scheve pully on the engine that drives the big alt. If so recheck the bearing on that shaft, mine is a little loose.

[boogiethecat]

Call me when (if) you get to san diego and havn't figured it out... i can probably figure out something here that will work for you- I'm real good at
making things work, and I have a very complete shop at my disposal...
I sent my phone number to you via email....

[boogiethecat]

Randy came over on Christmas, and we seem to have the situation under control.  The biggest obstacle was trying to figure out how the pulley attaches; it's a mind-game because too much of his old part is destroyed. 

  My take is that it's a tapered collar that goes between the (tapered?)pulley and the shaft- we have re-machined his pulley with a new taper and are building a new collar from scratch... but my question is, how does it normally get squeezed to hold on.  I've reinvented a sheave-style flange with three cap screws that works like QD pulleys but I have this notion that the whole thing is normally squeezed together by a big fat large diameter washer that would go between the shaft-nut and the pulley- tightening the nut squeezes the pulley down over the collar and everything gets tight... am I correct? Can anyone take me a photo? It probably doesn't matter at this point because what we're building will work fine.  But I'm always curious what the "real" way was.

[bevans6]

It is a tapered sleeve that fits inside the tapered hole in the pulley, and over the straight shaft and key in the keyway of the shaft.  There is a slot in the sleeve that fits over the key in the keyway of the shaft.  At the skinny end ( the inner end) of the tapered hole, the key also engages the pulley itself, the key is half in the tapered spacer and half in the pulley.  If you open up the hole too much you will lose the engagement of the key in the pulley, which is important.  If you need to you could make a taller key, but that is not good engineering.

The tapered spacer is proud of the pulley on the outside where the nut bears on it, and there is no washer.  As the nut is tightened, the spacer is forced into the pulley, and tightens down with the wedging action onto the shaft and grabs the key very tightly, as it is wedged tight by the nut.  I didn't look to see if the stock setup has the tapered collar still proud of the pulley when fully torqued or not, sorry.  I also did not notice if the tapered spacer is hardened steel or mild steel.  I think it would work better if the nut bore fully on the spacer, that will wedge things together very tightly, and obviously the tapered spacer should not bottom out on the shoulder that the pulley rides against.  I believe the torque spec on the nut is 125 ft lbs.

I believe the whole mess actually rides against a straight sleeve that is over the shaft and which the oil seal rides against, but again I can't quite remember the detail...

Hope this helps.

[boogiethecat]

Thanks, that all makes great sense.  His tapered sleeve was totally destroyed to the point it no longer existed, and the pulley's taper was damaged (ground away) just to the edge of where the key slot was, so we're machining out a new, much larger sleeve part, creating a new larger taper in the pulley, and I'll have to broach a new keyslot in it. Finally, I'll make two separate keys on opposing sides of the sleeve- one for the shaft, one for the pulley.
Cheers
gary

[bevans6]

Just remember that it's the pulley that has to bear on the inner seal spacer, not the tapered spacer.  So don't make the new tapered hole too big so that the pulley can't bear on the seal spacer.  What a fuss!  You might even think about making a new center hub and bolting the pulley outer rim to it.

On the MCI yahoo group someone was saying that some MC-8's came with that pulley as well as the MC-5's.


Brian

[Larry B]

As a thought to the cause of all this (besides the nut coming loose) you might want to check the outlet air pressure of the regulator to the belt tightener. If the reg. failed with a hole in the dia. or a broken spring on top of the diaphragm, you could see full line pressure (120psi) to the tightener. If I remember correct the regulator on mine was set at 26psi. This excess pressure might have been put  too much side load on the pulley causing it to work loose. If you had too much side load the bearing on the inside of auxillary drive assem. could be suspect. If the pulley is off ,it is only 5 more bolt to check the bearing before you put it all back together.

[rv_safetyman]

Randy, you are certainly in good hands.  Gary is extraordinary talented!!

I hope you have had a chance to enjoy his magical place and some of his fabulous creations.

Jim