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Discussion Starter · #1 ·
Ive seen some talk of machining the C4 forward drum to accept a metal band instead of welding the peanut holes up. Ive been running welded drums and Ive never broken one even under somewhat severe duty but i thought I'd try something new. Has anyone used one of these before under 800+ HP conditions? Here is one I made this afternoon by machining the hub to the end of the peanut holes and pressing a steel slug over the exposed area. Its relieved for a roller bearing. I'm just wondering if removing that much metal weakens the drum. I had to go down anout 1/2 inch to clear the indentations and in to the inner wall of the indents ...although I always wondered if welding it weakened the drum too.

http://users.adelphia.net/~mikeandnatasha/drum.jpg
 

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Thanks Greg.

I've been running this setup the last half of the drag season with no problems. So far so good.
 

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Are those sleeves interference fit, silver soldered or welded?
Is anything done to limit the corrosion between the two surfaces?
Paul
 

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I still like the welding option, the way it shrinks the housing and tightens up the splines has got to be a major plus. Its also quick and easy to do.
 

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On 2006-11-11 13:48, 64 TBOLT wrote:
corrosion between the two surfaces???

in a oil soaked environment
You read my mind.
 

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Discussion Starter · #8 ·
Even if it werent in an oil soaked environment you are talking about a 4 thousandths or greater press fit. Took 15 tons of hydraulic pressure to "slip" it over the factory hub . As far as that hub is concerned those parts are one and the same now. I'm sure if you were to throw it in a salt water bath the hub would disintegrate in a few hundred years. The sleeve would still be there though....Stainless steel.

That whole metal expanding thing is WHY I think the sleeve might be a better idea. The crystalline structure of the parent metal gets altered by the welding to the point where the metal deforms. Thats probably not a great thing. Hey, Ive run them like that for years but I don't think it actually makes the metal stronger in the way you think it does. It makes it thicker to be sure but I still think it actually weakens the steel in the hub area
 

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I agree on the strength bit and always wondered ,but hey it seems to work.Prob all it does is offer support where there isn't any.

So you guys that have done this,what dimension did you go down.Just to the botom of the holes i assume.
I might try Jay at broader and get the bearing he uses ther too I,m going to try his manual kit soon anyway
 

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I took the diameter of the cut down just until the peanut holes where cleaned up. I then made the ring to press fit. I don't remember the diameter off hand. The cut was to the bottom of the holes.
 

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Discussion Starter · #11 ·
I just did one tonight on a never used NOS C4 drum. Got to love ebay. It took .450" deep to get past the peanut holes and the center was exactly 1.250" wide.
 

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Corrosion can be caused any time two dis-similar metals are in contact. The transfer of ions causes it. Salt water can increase it or decrease it depending on the metals. Are the two metals (the hub and the sleeve) the same material? Are they compatible steels?
That is all I was asking. It is a valid concern.
Furnace welding does not produce crystalization and it can be tempered to take care of the canges in the temper of the metals, furnace brazing doesn't cause any change in the parent metal at all. It isn't as strong as steel but it is more elastic. Both welding processes are proven and viable techniques. Press on sleeves are also a proven process in many different industries. Care is always taken to assure the compatibility of the materials that touch. All three ways tighten up the splines for a more secure hold on the shaft and all three processes keep the splines from wedging open with the application of torque. You can buy drums with out the kidney holes for less than it costs me to have a single drum furnace brazed but not as cheep for ten as I can have ten furnace brazed. So, the only question that I have is: where do I find stock that is compatible with the drum?
Paul

<font size=-1>[ This Message was edited by: PaulS1950 on 11/13/06 12:22pm ]</font>
 

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On 2006-11-12 20:51, mikeandnatasha wrote:
I just did one tonight on a never used NOS C4 drum. Got to love ebay. It took .450" deep to get past the peanut holes and the center was exactly 1.250" wide.
Thanks Mike and cleveland style.Think i'll be giving this a shot when i get a chance.
 

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Discussion Starter · #14 ·
On 2006-11-12 21:19, PaulS1950 wrote:
Corrosion can be caused any time two dis-similar metals are in contact. The transfer of ions causes it. Salt water can increase it or decrease it depending on the metals. Are the two metals (the hub and the sleeve) the same material? Are they compatible steels?
That is all I was asking. It is a valid concern.
Furnace welding does not produce crystalization and it can be tempered to take care of the canges in the temper of the metals, furnace brazing doesn't cause any change in the parent metal at all. It isn't as strong as steel but it is more elastic. Both welding processes are proven and viable techniques. Press on sleeves are also a proven process in many different industries. Care is always taken to assure the compatibility of the materials that touch. All three ways tighten up the splines for a more secure hold on the shaft and all three processes keep the splines from wedging open with the application of torque. You can buy drums with out the kidney holes for less than it costs me to have a single drum furnace brazed but not as cheep for ten as I can have ten furnace brazed. So, the only question that I have is: where do I find stock that is compatible with the drum?
Paul

<font size=-1>[ This Message was edited by: PaulS1950 on 11/13/06 12:22pm ]</font>

Still think you are over thinking the problem. Ive been using 316L Stainless Steel. There is always a problem of galvanic corrosion in the presence of an electrolyte whenever any two dissimilar metals contact but goven the environment which is essentially an oil bath I dont think there is a problem here. Certainly not a problem that will manifest itself in the time span between transmssion freshenings and inspections. The only time you would need to do this mod is in very high HP applications and in those situtaions you'd tear down the transmission for inspection annually or bi annually anyway. Not trying to put widgets on the moon here.
 

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Just wondering if anybody has actually broken a welded hub??
 

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On 2006-11-13 11:13, cmf60 wrote:
Just wondering if anybody has actually broken a welded hub??
I have never heard of a welded hub breaking. I don't have anything against a welded hub. It is a proven method of strenthening the drum. The problem I have is that I am not a welder. I didn't feel comfortable welding on iron that I have no experience with. I am a machininst so the method of the fitted ring is much easier for me.

As for the corrosion, I am thinking it is a non-issue. I have only done this one trans with the fitted sleeve. I consider it a test. If it works, great. If not, then I consider it something learned. I would not do one for a customer until it is proven out. It has done well thus far, but I will be tearing it down this winter to take a look see. I have a couple other trial pieces in it right now.
 

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You may be right - it might be a non-issue. I think I will stick to the oven brazed drums until there are a few miles on the press-fit sleeves. If there is galanic reaction it will affect the center of the hub first. After a period of ten years, if nothing is going wrong, I may give it a try. If I can find a match for the metal I might give it a try before the ten years are up. I would rather do it on my own tranny first than on a customer's transmission. If it takes ten years to show symptoms it migh not be a big deal to some but even at ten years it is not acceptable to me if there is a problem that causes the unit to fail because of a modification. That is just my stubborn way to how I respond. I am not placing my feelings or limitations on anyone else. I am in no position to judge what you are doing - just what I am willing to do. I know the brazed units don't fail and that they are safe in every application that I have used them. Experimentation is what hotrodding is all about - I am at a disadvantage because I must use myself to test those things that I am unsure of - which takes a lot longer sometimes. Keep us all posted on your success!
Paul
 
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