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Discussion Starter #1
I went to the track Friday night for the first time since I put Eibach drag springs and Strange adjustable struts and shocks in the car. After my 4th run the track officials pointed out that I was leaving aluminum chips on the track at the starting line. Not only was the emergency brake cable bracket rubbing on the aluminum driveshaft but the shaft was also rubbing on a spot weld on the the top of the tranny tunnel.



By my measurements the driveshaft was 90mm in diameter and the diameter at the deepest part of the score is 87.3mm. What is the wall thickness of the driveshaft? Could I have this repaired by welding and rebalancing or should I look for a new driveshaft?

I know I have other problems that need to be addressed before I put the aluminum driveshaft back in.
 

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with these things running over 250.00$ new I'm pretty sure you can find a shop to repair it for way under that. Maybe if they were still 150.00, a replacement might be the way to go. I'd see what shops would charge and go from there.
 

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The question is, will this negatively affect the structural ingerity of the piece? If the answer is yes, replace it. If it's no, then leave it. Hard to say either way. If it was repaired via welding, I know I wouldn't want that much heat introduced into my driveshaft. Post this up in the Lounge.
 

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If the person doing the welding knows what they're doing, there won't be any question of the integrity of the driveshaft. In most cases, if welded properly, the new weld will become stronger than the metal/alloy itself.
 

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Discussion Starter #7
As an update I will probably be getting a new driveshaft. I talked with a local driveshaft repair shop (shaftmasters.com) and David said if it's .125 wall thickness it can be re-tubed. As it turns out the shaft has .114 wall tubing so it's junk. They apparently don't want to weld it because of the possibility of heat warpage. In the meantime, I'll use the old steel shaft.
 

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Welcome to the world of destroyed-by-the-parking-brake-bracket driveshafts!

It happens just about every time we lower these things.
 

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whose going to step up to the plate and design a different mounting system to rectify this situation?
 

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Discussion Starter #11
I X L said:
Welcome to the world of destroyed-by-the-parking-brake-bracket driveshafts!
And my ticket in only cost me $235!!!!

I'm having Shaftmasters build me a new aluminum driveshaft. They'll use my u-joints and yokes but the shaft wall thickness will be .125 aluminum material. I dropped it off at lunch today and the new one will be ready tomorrow at noon.
 

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The_Mustang said:
whose going to step up to the plate and design a different mounting system to rectify this situation?
Anyone have any good pics of the bracket with and without the DS installed? That would be a good place to start. Hell I probably need to check mine :mad:
 

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gustang818 said:
I X L said:
Welcome to the world of destroyed-by-the-parking-brake-bracket driveshafts!
And my ticket in only cost me $235!!!!

I'm having Shaftmasters build me a new aluminum driveshaft. They'll use my u-joints and yokes but the shaft wall thickness will be .125 aluminum material. I dropped it off at lunch today and the new one will be ready tomorrow at noon.
I'm not sure I'd name my business "Shaftmasters". Maybe Mastershaft or something...:confused:
 

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STREETFIGHTER50 said:
****! I just installed my aluminum DS last weekend! I'll be lowering the car probably next week. Am I gonna have issues with the parking brake?
Probably so. Take some good pics while you're under there of the bracket setup if you think about it.
 

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Not trying to be an idiot or anything, but I can't help but wonder if an aluminum DS actually does that much for the car to worry about it getting chewed up or buying it for the high price in the first place.

I know it's lighter, but how much lighter is it? Last I checked my stock DS isn't really that heavy.
 

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It's not just about it being lighter, it comes with new u-joints. We all know the oem ones fail quite a bit, sometimes pretty quickly. Mine were going back in 02 when I got the driveshaft.
 

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Discussion Starter #18
I haven't weighed them but just taking the aluminum shaft out and putting the steel shaft in, the aluminum feels significantly lighter. There are also benefits to the rear end and tranny from the reduction in rotating mass. In fourth and fifth gear your driveshaft is spinning as fast as or faster than your engine. Driveshaft mass when multiplied by 4000 rpm or so equates to significant reactive centrifugal force. Since the aluminum shaft is lighter there is less of that.
 

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Understood. However, if the shaft is properly balanced, there shouldn't be any reactive centrif. force to deal with. I've never had an aluminum shaft in my 'Stangs so I don't have a reference point. But I've never had any prob. with the stock units.

Why do they make the alum. D/S so much bigger than the stock steel piece? Is there any evidence of a performnace gain from the alum. D/S? Just curious, I'm in no way ridiculing the use of these things in the least.
 

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Discussion Starter #20
It's not a matter of balance. It's a matter of mass. If you've got a rock on the end of a rope and are spinning it in a circle over your head, when you let go of the rope the rock flies off in a straight line. The mass that makes up the driveshaft also wants to fly off in a constantly changing straight line--thus the reactive centrifugal force. I don't know that there are necessarily any performance gains from a lightweight aluminum driveshaft but it puts less stress on the other driveline parts. I would assume the larger tube is stronger than a smaller diameter tube.

Steel driveshafts work perfectly fine--in the 30+ years I've owned cars and trucks, this is the first one I've had with an aluminum driveshaft. Steel driveshafts just may not be the optimum part for the application. I want my car to go faster but I also want parts (especially expensive parts and difficult to service parts) to last as long as possible before replacement.
 
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