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My local corvette "guru" and I are at it again. He claims a vintage vette should never be jacked up at just one point. He thinks that both sides need to be jacked at the same time as to not cause any undo-stress to the body. My argument is simply that GM just didn't build them that fragil. After all, jacking instructions in the owners manual and service guide support this. Does age do to time change this? Is he really right? The archives seem to contain all you would want to know about jacking except this opinion.
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Re: The Truth
Several folks report damage to C2/C3 front crossmembers resulting from jacking the front end from this point. I have always jacked my cars this way and will probably continue to do so. I also jack C1's from the third arm bracket. Dale Pearman advises that the third arm bracket on earlier C1's (maybe 58 and earlier?) were a little weaker than the later ones and that the use of a "saddle" made of a notched 2X4 might be a good idea on these cars.
The cars are going to flex a little, but should not do so excessively unless there is some sort of frame issue or poorly repaired body damage. If the car breaks in half from being jacked up, it probably isn't strong enough to take a pot hole either. -
Re: The Truth
Ed,
Is there a pattern out there for the fabrication of a saddle? Do you have any specific measurments or do you just scrib and fit? Is the exact placement at the third cross member? Do you use it only in the front or in the rear too? Seems like alot of work just to change a tire. I certainly don't want to cause any harm to my car!
Thanks,
JonComment
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This is for the front only. All Dale was refering to doing was notching out a short piece of 2X4 so it would bridge the third member bracket and put the lifting force on the front crossmember instead of the bracket. Apparently the bracket on the pre 58 cars was a little less beefy than the later cars and it's possible to break the bracket by using it as a lift point.
If you're just changing a tire, the best lift point is the frame, just fore or aft of the wheel.Comment
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Gotcha- Thanks Ed *NM*
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Re: The Truth
If anyone would like to see what happens to a third arm support bracket when used improperly in jacking, email me for a photo of the one I just removed; clearly shows the weld line where it had been broken across the round face.
... Al '58 #378 NCRS, SACCComment
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Re: The Truth
Al, does your early 58 car have the older style bracket? Dale indicated to me that the brackets on the newer cars are less fragile. The conversation was sort of like " you really ought to use a bridge block, but I never bother with the ones that have new style brackets", or something to that effect.Comment
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Re: The Truth
Ed,
Al's support was broken because someone jacked under the nut instead of the heavy cast bump on the bottom of the support. I still jack my 60 under the bump as it fits in my jack pad nicely, and I cant imagine how someone could break the support by jacking there.
Regards, John McGrawComment
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Agreed.
I don't know that the bracket changed from 58 to 62.
... AlComment
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John, Al: I too have jacked a variety of solid axles using the "bump' for years with no adverse affects. As John points out it fits the pad on the floor jack nicely too. I guess the best thing would be some sort of bridge arrangement that was secured to the jack pad with some sort of rubber covering to aid friction, but I'm gonna hold off on that until I run out of other projects. According to Dale P though, the guys with pre 58 cars may want to look at this a little more closely. I have never owned a pre 58, and don't know what the difference is.Comment
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Re: The Truth
I noted on the Solid Axle listings that Noland Adams does not support jacking on the thirdarm period--or that is how I read his post. I am anxious to read his article on the thirdarm once he finds it and posts it. For me, I ain't gonna jack it using the thirdarm. Take my chances on breaking the car in half using some other point.Comment
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