I dropped off my 4104 fan hub at a machine shop last Friday. I asked the owner if he could weld it up solid and balance it. He said yeah, they could do that. Yesterday they call and say its ready. I go to pick it up, and when she sets it down in front of me, it just didn't look right. After I pick it up to chk it out, I see they have welded it together backwards!!! They reversed the inner sleeve! The hub for the blade and the keyway for the crank are on the same end! I show it to the guy who welded it, and he's like, "yeah, that's how it was when I got it!". He offers to cut it apart and redo it. I question how well balanced its going to be after that. "Balance! We can't balance it." I speak to the owner and ask him about the balancing. He chuckles a bit and says they can kinda balance it. "Kinda? Its either balanced or it isn't, no kinda about it!" He says they will cut it apart and fix it right them. Will take 20, maybe 30 minutes. 45 minutes later the lady says their working on it. "I hope so, it was supposed to be done 15 minutes ago. How much longer?" She says she has no idea. <crickets> "Could you find out?" She comes back and says its going to be about a half hour. I had to leave to get home to be with my granddaughter. I wonder what I will find when I get back there today?
should have taken it to drive shaft shop.... it might not be too late >:(
Never thought of that. I picked it up and dropped it off at the shop where my bus is. The head of the shop thought it looked pretty good.
It has to be true with the crank!!! And has to be balanced ,otherwise it will eat fans.rdw
John if you're going to mount a fan on that hub I can tell you form experience that a fan, plastic or metal won't last very long before it disintegrates mounted directly to the crankshaft. That's why it had an isolater from the factory.
The fan with the adjustable blade pitch will be a little better because you can at least keep a check on the bolts that hold the blades in. I can't think of the name of that fan, maybe Wing something.
Ken
Different experiences I guess. Mine has been solid mounted for over 13 years and 100,000 miles. Works for me. rdw
Well the machine shop said it ran true. I guess how could it not? They sleeved the two pieces and pressed them together, then welded it. I will ask the shop foreman if he thinks I should pursue further balancing. The blade I ordered is a metal hub with nylon blades.
My failure may not have been caused by the solid mount hub. I always blamed the solid hub because after it failed I read somewhere that any fan should not be mounted directly to crankshaft because of the vibrations produced by the diesel combustion process. I put the variable pitch fan on before I sold it and the current owner says he has to keep a check on the bolts that hold the blades in the hub. I think Uncle Ned has this style fan and like my old 4104 it also has a 6V92 so I'm really not comparing apples to apples. Of course the 671 is a very different engine.
A plastic fan with a metal hub is the style that failed on mine and took out the radiator.
Ken.
The GM buses with a direct fan drive use a rubber isolator we ran into that when Red Ryder had all the parts made for his,we were advised by Luke and Chris not to use the direct drive without the rubber coupling so we went back to fluid drive.
LOL I see Mikes $$$$ worth of machine parts in my shop daily
Clifford,
We left those parts so you could tell other folks not to do what I attempted. Those GM engineers knew a little more about engine cooling than I do. Thanks again for saving my bacon.
Clifford, we are trying to work in a fall trip to get the torus rebuilt. I'll let you know if we get it figured out.
Tom Caffrey
I think we need John Vickery in on this.
Our friend from Costra-rico that had all the GM insigna's made was trying to find some fan hubs to have reworked
in his home country.
uncle ned
The garage just called. I expected him to say it was back together and to come pick the bus up. But things have gone from bad to worse. He started to put it all together. It would only slide on the crank about 2". He gave it a couple light taps, and if didn't budge. So he pulled it off, the weld broke and the inner sleeve pulled out about an inch! How did they shrink that inner sleeve?
Clifford what happened to Mikes? Mine has been welded sold since before I changed engines. Am I just lucky? rdw
Nothing happen we didn't install the pcs,Mike bought a engine from a 4107 that had a direct drive with the clutch and isolator the problem only the direct drive came with the engine less all the parts from the drive out and there was no parts to be found
Someone told him the torus setup would not work on the engine so he began having parts made ,he went home for the week end and I removed all the parts and install his torus fan setup and he has been happy, he had a valve problem but repaired it all has been well since I guess he never called ragging on me.
Mikey and Tom Caffrey are my favorite bus people nothing excites those 2 my type people ;D lol the GM people seem to have adopted me for some reason GM people are rare breeds I enjoy the GM people
Quote from: pvcces on August 16, 2015, 06:48:32 PM
Clifford, we are trying to work in a fall trip to get the torus rebuilt. I'll let you know if we get it figured out.
Tom -I sent you a PM.
;)
I picked up the hub. It would only slide on the crank a bit over an inch, right to the point where the weld was. The weld had no real penetration. Using supper glue would have done as much good. Thank God they had shrunk it. It sure would have broke in short order, then how would you pull it off?
I'm at the machine shop. It shrank 0.0015 right at the weld.
pray tell...why would you go back to the machine shop ???
I don't believe this going to work out to well for you John Z I hope it does
I went back there to show it to him. It would seem to be an easy fix. Grind it, weld it, and put it on a lathe.
Cliff, I'm praying it works. I certainly am open to other solutions. I have too much money invested in my bus to turn it into a playhouse for my granddaughter. :-)
Maybe it will John I am just parodied about a engine that uses a balance shaft and a harmonic balance
Ok Cliff. I'll say a little prayer and keep my fingers crossed.
Sonnie and Mike told me that was a good running 6L-71 in your bus
perhaps with a big enough chunk of metal they could make a new one ?
Did you call Luke to see if he has a fan and hub?
Cliff, what you, Sonnie, and Mike did for us is still my favorite campfire bus story. Constant thanks to the three of you. I lucked out when I bought the bus. I knew nothing about buses other than which end was the front. The head of the shop has remarked several times how good the engine seems.
Yeah, if it doesn't fit perfect tomorrow, we may have to ask them to just make a new one.
Luke didn't have anything. Not sure putting another 40 year old hub in would be the best solution anyway.
The machinist showed me the hub on the lathe. It was set to true the bore that slides on the crank. So that is true to the outer surface. Then he chucked it into another lathe and checked for runout on the blade mounting surface. It ran out .003. He took a cut of that, so that surface is true to the bore also. No other appreciable runout on the other surfaces.
I then stopped by an industrial electric motor shop to see if they would balance it. Three guys wound up looking at it. They agreed it would be a waste of money to balance it. The old guy said "I guarantee you it isn't off by more than 10 or 15 grams!"
Keeping my fingers crossed.
The only fan that has been on my bus since I welded it up is the flex-a-lite. When the original fan self destructed I replaced it with a high dollar replacement from ABC, when it exploded in under a thousand miles I pulled and welded the hub . Being that the fan on my racer is rated to 10'000rpm I called flex-a-lite and ordered a off road pusher fan. Has been on my bus ever since. rdw
this is how we solved the fan drive issue on a 04 and allowed for some dampening to save the crankshaft
hth
Quote from: Decalsbyblondie on August 18, 2015, 10:49:09 AM
this is how we solved the fan drive issue on a 04 and allowed for some dampening to save the crankshaft
hth
got a parts and vendor list ? :)
Where you been Chris I was waiting for you to wade into this one ;D
to explain what you see in the photo.
the machined hub attached to the crank is made up of 2 separate pieces the first piece is bolted to the crank using the bolt removed from the old stock rubber fan drive,
the second piece is threaded into the first piece,
and finally the silicone truck fan clutch was manufactured at borg warner in a locked state this allows for the dampening needed between the fan and crankshaft
the fan itself is a off the shelf plastic borg warner stock item
after a little thought and engineering this has worked well for about 7 years...
no cooling issues at all
im working on part numbers for the fan and clutch drive we used, the hub parts we machined ourselves.
I think we kept the napkin er drawing we made it from
Chris I see Bob has broken another crankshaft on his 4104 you know where I can get a engine for him ?
Quote from: luvrbus on August 18, 2015, 11:11:04 AM
Chris I see Bob has broken another crankshaft on his 4104 you know where I can get a engine for him ?
cannot a lefty 8v71 fit in there ?
Clifford I put my feelers out for that engine for you, the guy is on vacation until Monday
ill let you now
RDW, so that blade was destroyed by the fan hub before it was fixed/welded?
Sorry slow replying. My rebuild had a hiccup. Just back out of the VA... Fan loss was before hub repair. Not sure on bw silicone fan drive..all I have seen have free wheeling through bearing on solid shaft, with lockup from heat. Then it's solid locked to drive. Silicone is lockup mechanism not dampening. rdw
I'm sure I'm wading into dangerous territory here but couldn't you use an electric fan used on high performance engines? Seems like after 40 or 50 years electric fans would have caught up to a mechanical fan. I'm sure someone has tried, but after all this hassle I'd be tempted to give it a whirl. JM
To begin, I had typed all the details of my picking up the new fan which finally came in. But after typing for 15 minutes, this forum locked up and lost it.
The fan came in totally wrong, including being made with the wrong rotation! So I'm having the old one balanced, and will use it this weekend. Not sure what I will do next to solve this.