Welding Subframe Connectors- Loading Required?
Where did you get your information from? IF the car is not on the wheels when welding SFRs, what are the negative consequences?
I was told by UMI that the car just needs to be level as when it is on a four-point lift where wheels dangle. They said the wheels should be loaded if the car is not necessarily level but on jack-stands like in someone's driveway.
I was told by UMI that the car just needs to be level as when it is on a four-point lift where wheels dangle. They said the wheels should be loaded if the car is not necessarily level but on jack-stands like in someone's driveway.
Hello,
The car should be be level and the suspension loaded completely when welding. A post lift will load all four wheels.
If I can help anymore please ask. Thank you!
Ryan
The car should be be level and the suspension loaded completely when welding. A post lift will load all four wheels.
If I can help anymore please ask. Thank you!
Ryan
What are the negative implications of welding when the suspension is not completely loaded?
Which type of lift is acceptable, lift 1 in the attached picture or lift 2? If lift 2 is not acceptable, why?
I think you meant a 4-post lift, like lift 1, will load all four wheels, not lift 2.
Which type of lift is acceptable, lift 1 in the attached picture or lift 2? If lift 2 is not acceptable, why?
I think you meant a 4-post lift, like lift 1, will load all four wheels, not lift 2.
Lift 1 would work
Lift 2 will not work because it doesn't load the suspension.
I think the reason you have to load the suspension is because that is how it lays most of the time and anything different will mess up the geometry of the car.
again, I think this is why.
Lift 2 will not work because it doesn't load the suspension.
I think the reason you have to load the suspension is because that is how it lays most of the time and anything different will mess up the geometry of the car.
again, I think this is why.
So how would the geometry being messed up manifest itself? What could be seen or felt? How would it be observed after the fact?
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Teching In
Joined: Feb 2010
Posts: 29
Likes: 0
From: Hopkinsville, KY
The purpose of SFCs is to make the entire car more rigid so that it does not flex. When the body is more rigid the car handles better, the panels remain aligned better and the t-tops don't leak as much. When you install the SFCs you want the body to be exactly as it will be on the road (suspension loaded) so that when you weld them in the body is as straight as possible.
If your suspension is unloaded when you install the SFCs then parts of the car that are not normally stressed are being stressed and the body will not be in its correct alignment. Welding in the SFCs when the body is abnormally stressed will give you a permenantly stressed body which will result in problems with panel gaps, t-top leaks and less than the best possible handling.
More importantly please note that the rep from UMI answered you in this thread and told you to install with the suspension loaded. Its your car do what you want.
If your suspension is unloaded when you install the SFCs then parts of the car that are not normally stressed are being stressed and the body will not be in its correct alignment. Welding in the SFCs when the body is abnormally stressed will give you a permenantly stressed body which will result in problems with panel gaps, t-top leaks and less than the best possible handling.
More importantly please note that the rep from UMI answered you in this thread and told you to install with the suspension loaded. Its your car do what you want.
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Originally Posted by NBM2002WS6Vert
If your suspension is unloaded when you install the SFCs then parts of the car that are not normally stressed are being stressed and the body will not be in its correct alignment. Welding in the SFCs when the body is abnormally stressed will give you a permenantly stressed body which will result in problems with panel gaps, t-top leaks and less than the best possible handling.
As you can imagine, there is a good reason I am asking these questions.
When I phoned UMI when my car was at the shop, I got the answer as stated in my first post. Now UMI posts a different message answer here. Surely companies that sell chassis/suspension parts have some responsibility to ensure their dealers install their parts correctly.
UMI was on-site and sold me the SFCs at the speed shop pictured (Speed Inc.), now after welding SFCs on lift 2 (unloaded) says "We have never had an issue doing the SFC's as we do. We support the frame evenly per side and the car sits level / true by doing so."
So somebody is not being completely on-deck -- which is it?
It is not me, but it is a speed shop, that should know better, is weld-installing in this fashion. Yes, I would have done what I want. Lesson is to never assume that a dealer for the company that makes the parts you want installed will do so with best practices.
When I phoned UMI when my car was at the shop, I got the answer as stated in my first post. Now UMI posts a different message answer here. Surely companies that sell chassis/suspension parts have some responsibility to ensure their dealers install their parts correctly.
UMI was on-site and sold me the SFCs at the speed shop pictured (Speed Inc.), now after welding SFCs on lift 2 (unloaded) says "We have never had an issue doing the SFC's as we do. We support the frame evenly per side and the car sits level / true by doing so."
So somebody is not being completely on-deck -- which is it?
It is not me, but it is a speed shop, that should know better, is weld-installing in this fashion. Yes, I would have done what I want. Lesson is to never assume that a dealer for the company that makes the parts you want installed will do so with best practices.
The purpose of SFCs is to make the entire car more rigid so that it does not flex. When the body is more rigid the car handles better, the panels remain aligned better and the t-tops don't leak as much. When you install the SFCs you want the body to be exactly as it will be on the road (suspension loaded) so that when you weld them in the body is as straight as possible.
If your suspension is unloaded when you install the SFCs then parts of the car that are not normally stressed are being stressed and the body will not be in its correct alignment. Welding in the SFCs when the body is abnormally stressed will give you a permenantly stressed body which will result in problems with panel gaps, t-top leaks and less than the best possible handling.
More importantly please note that the rep from UMI answered you in this thread and told you to install with the suspension loaded. Its your car do what you want.
If your suspension is unloaded when you install the SFCs then parts of the car that are not normally stressed are being stressed and the body will not be in its correct alignment. Welding in the SFCs when the body is abnormally stressed will give you a permenantly stressed body which will result in problems with panel gaps, t-top leaks and less than the best possible handling.
More importantly please note that the rep from UMI answered you in this thread and told you to install with the suspension loaded. Its your car do what you want.
Last edited by libertyforall1776; Jun 23, 2010 at 07:57 PM.
Teching In
Joined: Feb 2010
Posts: 29
Likes: 0
From: Hopkinsville, KY
Maybe you'll never notice a difference installing with the suspension unloaded. Maybe it won't cause a significant difference. However I think there is a good chance that unloading the suspension will put things farther away from their optimum alignment and my belief is if you weld something when it is crooked it will always be crooked. Pretty much everything you do with a suspension and frame when you get to the final positioning and tightening you want to do with the suspension loaded so that it maintains that position.
Sorry for the sarcasm, I see now the predicament your are in: getting mixed signals from folks who should know better.
Maybe we should sum-up the recommendations for installing weld-in SFCs as that it is BEST to be welded-on when the car's suspension is loaded on a level, planar, drive-on (4-post) lift. Short of that, its probably OK to weld-on the SFCs using a 4-point frame (2-post) lift as long as the lifting points are adjusted to lift the car squarely (i.e.: so that it doesn't induce any twist) from a level, planar position on its wheels, AND that the car's doors and windows are closed and t-tops (if applicable) are installed.
Regardless of lift type, it is important that it be installed and leveled properly before using it as "reference plane" for chassis work.
The primary idea is to have the car in is most-neutral un-stressed condition when the welding occurs. In reality, roads, driveways and garage floors are not perfectly level, so some stress is being induced on the suspension / frame of the car at all times. Its best for the strength of the welds and overall alignment of the chassis if those stresses are added to an un-stressed chassis rather than being added to stresses built-into the chassis from welding the SFC in a stressed condition.
Maybe we should sum-up the recommendations for installing weld-in SFCs as that it is BEST to be welded-on when the car's suspension is loaded on a level, planar, drive-on (4-post) lift. Short of that, its probably OK to weld-on the SFCs using a 4-point frame (2-post) lift as long as the lifting points are adjusted to lift the car squarely (i.e.: so that it doesn't induce any twist) from a level, planar position on its wheels, AND that the car's doors and windows are closed and t-tops (if applicable) are installed.
Regardless of lift type, it is important that it be installed and leveled properly before using it as "reference plane" for chassis work.
The primary idea is to have the car in is most-neutral un-stressed condition when the welding occurs. In reality, roads, driveways and garage floors are not perfectly level, so some stress is being induced on the suspension / frame of the car at all times. Its best for the strength of the welds and overall alignment of the chassis if those stresses are added to an un-stressed chassis rather than being added to stresses built-into the chassis from welding the SFC in a stressed condition.
