Halfshafts: Level or Slanted ?
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Le Mans Master
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From: B'Ville NY
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St. Jude Donor '05
Halfshafts: Level or Slanted ?
Bence just pointed this out to me and got me a bit curious. My halfshafts are level with the ground which is what I thought was preferred with our cars :confused: ?
Benc stated, "I remember hearing that your halfshafts shouldn't be straight like that. Something about whenever it squats the halfshafts go over center."
Now that I'm thinking about it, does it make since that if they pass the center point of travel, they would simply be the opposite but same angle of if the halfshafts were pointing down ? With the halfshafts level the side yokes their maximum travel into the differential, and moving out from this point as they travel in either direction.
Maybe it's different depending on application ? (I need to change the batteries in my keyboard, it keeps dropping letters as I write :rolleyes: )
Benc stated, "I remember hearing that your halfshafts shouldn't be straight like that. Something about whenever it squats the halfshafts go over center."
Now that I'm thinking about it, does it make since that if they pass the center point of travel, they would simply be the opposite but same angle of if the halfshafts were pointing down ? With the halfshafts level the side yokes their maximum travel into the differential, and moving out from this point as they travel in either direction.
Maybe it's different depending on application ? (I need to change the batteries in my keyboard, it keeps dropping letters as I write :rolleyes: )
Race Director
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From: Living in the Hartland
Re: Halfshafts: Level or Slanted ? (SmokedTires)
Makes sense to me having them level so you get max travel in either direction. MIght want to do it with you in the car or someone about your weight. I have air shocks so I can level them out when my 400+ pound friend rides with me, he is very hard on seats and furniture. :(
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Le Mans Master
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From: B'Ville NY
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St. Jude Donor '05
Re: Halfshafts: Level or Slanted ? (Fevre)
Here's a page from a Herb Adams book I have called "Corvette Handling, A performance handbook". It shows the halfshafts level with the ground.
Fevre thinking about it, I wonder if it'd prolong the life of the side yokes because of the greater area sliding in contact with the diff seal.
Fevre thinking about it, I wonder if it'd prolong the life of the side yokes because of the greater area sliding in contact with the diff seal.
Safety Car
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From: St. Charles IL
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Re: Halfshafts: Level or Slanted ? (SmokedTires)
Seems like there are a lot of variables here. If the car was bone stock, with the factory equipped size tires, you could adjust the rear bumper height as per spec and see where the half shafts wind up. That would all change as soon as tire size is changed, etc. From a wear standpoint it would make sense to me they be as straight as possible. :confused:
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Le Mans Master
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From: B'Ville NY
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St. Jude Donor '05
Re: Halfshafts: Level or Slanted ? (LATNC3)
I think most people will have slanted haftshafts, it all depends on how far you Corvette is either raised or lowered. The bolts I recieved with my VBP Street & Slalom Suspension kit allows me to lower the back of the car enough to levelout my halfshafts.
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Safety Car
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From: Severna Park Md
Re: Halfshafts: Level or Slanted ? (arrio76)
Mine are ever so slightly angled downward to the outside. Slight angles arent a problem. Thats what U-joints are made to acomodate. Its not so much the angle of the shaft itself that can be a problem. Its whether the angles in relation to thier mounting points at each end of a shaft are equal. If you gave a 2 degree angle at the outside, and a 2 degree angle in the oppisite direction at the inside, then everything will be fine. I think our suspensions are set up that way. What ever degree of angle you have on one end you have the same degree of opposite angle on the other. So as the susp moves up and down these angles change. But they remain equal to each other in oppisite directions. This is what keeps it working smoothly. Now if you had a shaft with a 6 degree mounted angle at one end, and a 1 degree mounted angle in the other direction at the other, that would not work so smoothly. I learned some of this shaft angle tech from working on lifted 4x4's.
Le Mans Master
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From: San Diego CA
Re: Halfshafts: Level or Slanted ? (SmokedTires)
Halfshafts should be slightly angled down on the outside or level (when the car is loaded) halfshafts when loaded should not be angled above horizontal.
mine are slightly down agnle when I look at it from the rear - when loaded they still have a very slight angle - but are nearer to level. Level is ok if loaded but if you angle up from the diff with halfshafts (when loaded) this is not the optimum.
mine are slightly down agnle when I look at it from the rear - when loaded they still have a very slight angle - but are nearer to level. Level is ok if loaded but if you angle up from the diff with halfshafts (when loaded) this is not the optimum.
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From: Waterloo ontario Canada
Re: Halfshafts: Level or Slanted ? (SmokedTires)
My half shafts are level when I look but I am not in the car obviously. To me running the universal almost flat but not quite is easiest on them.
Maybe what Shane is saying is that the most important time for the half shafts to be at their best is when the car is under hard acceleration. If the half shafts start out level then when the car squats under hard launch the half shafts go through an angle that is less then idea. If you start off with them at less then idea and they end up under launch in the idea position isn't it better? This is for a drag car.
To me for a normal running cruiser I want them to be close to level all the time.
I might be putting my own ideas in here and Shane doesn't agree?
Maybe what Shane is saying is that the most important time for the half shafts to be at their best is when the car is under hard acceleration. If the half shafts start out level then when the car squats under hard launch the half shafts go through an angle that is less then idea. If you start off with them at less then idea and they end up under launch in the idea position isn't it better? This is for a drag car.
To me for a normal running cruiser I want them to be close to level all the time.
I might be putting my own ideas in here and Shane doesn't agree?
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Le Mans Master
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From: B'Ville NY
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St. Jude Donor '05
Re: Halfshafts: Level or Slanted ? (norvalwilhelm)
This stuff seems to be making sense and if this is the general consensus, then I will be adjusting then tomorrow ;) .
Le Mans Master
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From: Austin TX
Re: Halfshafts: Level or Slanted ? (SmokedTires)
I discussed this not long ago with a fella here in Austin who runs his 71 in Open Road Races in the 130 to 150 classes. His opinion is that half shafts should be set up with about 3 degree downslope from pumpkin to hub. He believes this puts less strain on the u joints which he wants to preserve at those speeds.
Safety Car
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From: Clymer PA
Re: Halfshafts: Level or Slanted ? (SmokedTires)
Mike:
I'm sorry if I am causing problems for you, I was just curious myself. I believe it was Jim (427hotrod) that I recall stating this in a previous thread. He stated that the halfshafts should not be straight when the car is just sitting there. When you launch the car and it squats, that is when the halfshafts should be straight. If they are straight to start with then when you launch it they go over center....which I think is less than ideal.
I ran into this problem with my stock 9 leaf spring when I went drag racing with the slicks. My car bites hard off the line and the 9 leaf wasn't strong enough. My frame snubbers were actually hitting my trailing arms causing my rear suspension to go "solid" and my halfshafts to go over-center.
I could be wrong though...it wouldn't be the first time :) . That's what I like about this forum, I am constantly learning everytime I get on here.
I'm sorry if I am causing problems for you, I was just curious myself. I believe it was Jim (427hotrod) that I recall stating this in a previous thread. He stated that the halfshafts should not be straight when the car is just sitting there. When you launch the car and it squats, that is when the halfshafts should be straight. If they are straight to start with then when you launch it they go over center....which I think is less than ideal.
I ran into this problem with my stock 9 leaf spring when I went drag racing with the slicks. My car bites hard off the line and the 9 leaf wasn't strong enough. My frame snubbers were actually hitting my trailing arms causing my rear suspension to go "solid" and my halfshafts to go over-center.
I could be wrong though...it wouldn't be the first time :) . That's what I like about this forum, I am constantly learning everytime I get on here.
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From: phila Pa
Re: Halfshafts: Level or Slanted ? (bence13_33)
hey guys, te wayi see it is it all depends on what you want out of your car. if yo are just the every day driver who just goes crusingi woul say keep them level when jsut sitting. but for the performance motor head, keep a slight angle for launching and sqat into turns. it seems lgical to have them a bit slanted when sitting still for performance reasons
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Le Mans Master
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From: B'Ville NY
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St. Jude Donor '05
Re: Halfshafts: Level or Slanted ? (1971_CorVette)
Shane, I glad you brought this up. This is the beauty of the forum, I too am constantly learning new things about my car :).
:iagree: That's what I too am thinking now. I will be raising the rear slightly. This could be my part of my traction problem when I go to the strip too, it seems I can never get a good launch off the line. :cheers:
hey guys, te wayi see it is it all depends on what you want out of your car. if yo are just the every day driver who just goes crusingi woul say keep them level when jsut sitting. but for the performance motor head, keep a slight angle for launching and sqat into turns. it seems lgical to have them a bit slanted when sitting still for performance reasons
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From: Marlborough MA
Re: Halfshafts: Level or Slanted ? (1971_CorVette)
In the VIP article that can be found on corvettefaq.com, the article talks about having the inner U-joint (near the dif) higher by approx. 3/4" (I think it was 3/4" - check article) than the outer U-joint. The reason given was that the change in camber was not as severe when starting off in this region. It was do to this relationship being "fixed" that the article recommended raising the differential up into the car to lower the car, and not do any more lowering with the bolts attaching the spring to the trailing arm.
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From: Was New Orleans but swam to Baton Rouge LA
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Re: Halfshafts: Level or Slanted ? (SmokedTires)
Here is a question are yall checking them with weight in the car? I would think that some angles would show or disappear when someone is sitting in the car. I would think that having weight would be how the car was driven and when you want 1/2 shafts level.
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Re: Halfshafts: Level or Slanted ? (norvalwilhelm)
My half shafts are level when I look but I am not in the car obviously. To me running the universal almost flat but not quite is easiest on them.
Maybe what Shane is saying is that the most important time for the half shafts to be at their best is when the car is under hard acceleration. If the half shafts start out level then when the car squats under hard launch the half shafts go through an angle that is less then idea. If you start off with them at less then idea and they end up under launch in the idea position isn't it better? This is for a drag car.
To me for a normal running cruiser I want them to be close to level all the time.
I might be putting my own ideas in here and Shane doesn't agree?
Maybe what Shane is saying is that the most important time for the half shafts to be at their best is when the car is under hard acceleration. If the half shafts start out level then when the car squats under hard launch the half shafts go through an angle that is less then idea. If you start off with them at less then idea and they end up under launch in the idea position isn't it better? This is for a drag car.
To me for a normal running cruiser I want them to be close to level all the time.
I might be putting my own ideas in here and Shane doesn't agree?
For me level is the best thing, when the suspension travels (and mine used to travel a little bit because of stiff springs and dampers) the angle doesn't change a lot over the entire distance of movement, this makes that the resulting " length" of the 1/2 shaft stats as close to what it's at max (level) as possible, resulting in the least camber change.