Jacking up C3 Front end or rear end in "one Shot"

[Ken B.]

Hi all,
Sorry if this is posted in the wrong area. Relatively new member. Still trying to figure out this site. Seems like everything goes in Technical Discussion.If there are other specific forums, I just haven't located them.

Is it possible to lift the front end of a 1978 Corvette in "one shot" instead of jacking up the left side and then the right side? Same question for the rear also.
Thanks

[Mark E.]

Re: Jacking up C3 Front end or rear end in "one Shot"

Ken,

Lots of discussion about this here and CF. Search "jacking".

The shop manual shows the front crossmember as a floor jack location for lifting the front.
The rear spring bracket below the differential is not an "official" lift point for the rear, but some use it anyway. This requires a gap between the exhaust pipes wide enough for a wood spacer or similar jig. The exhaust pipes are too close together on some cars to do this.

Similar deal with lifting the side of the car along the frame where the transmission crossmember connects- not recommended by Chevy but many do it.

[David H.]

Re: Jacking up C3 Front end or rear end in "one Shot"

Hi all,
Sorry if this is posted in the wrong area. Relatively new member. Still trying to figure out this site. Seems like everything goes in Technical Discussion.If there are other specific forums, I just haven't located them.

Is it possible to lift the front end of a 1978 Corvette in "one shot" instead of jacking up the left side and then the right side? Same question for the rear also.
Thanks

Ken

Welcome to NCRS Tech Board.

I would not use a jack on front crossmember to lift a car.

If you do, then link below is to type of tool used when removing dents caused by lifting with a jack.

Dave

1963-1982 Corvette Front Crossmember Lower Dent Repair Tool (corvettecentral.com)

[Russ S.]

Re: Jacking up C3 Front end or rear end in "one Shot"

You can use the front crossmember just fine if you use a wood block that spans the entire crossmember from front to rear.

[Keith W.]

Re: Jacking up C3 Front end or rear end in "one Shot"

Not to weigh in on the crossmember discussion but I always pop the hood, open the doors and pop the convertible top before jacking or lifting the car. I have a C3 as well.

[Ken B.]

Re: Jacking up C3 Front end or rear end in "one Shot"

Thanks for the information / advice. I appreciate it

[Edward J.]

Re: Jacking up C3 Front end or rear end in "one Shot"

Ken, no matter where you decide always use caution. If you need to jack up jack one side at at a time, on front put jack under front lower control arms, and rear use the rear corners of frame. If you need two wheels off the ground use what others have posted. For safety with both wheels of use a good pair of jack stands.

[William F.]

Re: Jacking up C3 Front end or rear end in "one Shot"

I jack where the manual says certain points on side frame rails

[Mark E.]

Re: Jacking up C3 Front end or rear end in "one Shot"

I jack where the manual says certain points on side frame rails

The issue is when the car is lifted using these points one at a time causing the frame to twist.
This puts stress on the body and its bonding to the car. Okay to do once in awhile during a roadside emergency but best to avoid when possible.

[William F.]

Re: Jacking up C3 Front end or rear end in "one Shot"

You mean the CSM lists these jack points but only to be used 4 at a time-2 on each side of frame and not individually?

[Mark E.]

Re: Jacking up C3 Front end or rear end in "one Shot"

You mean the CSM lists these jack points but only to be used 4 at a time-2 on each side of frame and not individually?

Breaking the body's bond to the underlying structural steel is a risk when twisting the frame. When I acquired my '70, the bond between the top rear corner of the right fender and the cowl was broken. The previous owner said it popped while lifting the RF corner of the car. I've seen several cars with this issue. I suspect age and rust weakens the bond over time also.

Regarding the service manual, the risk is minimal if lifting just enough to change a flat while the car is under warranty. But avoid lifting one corner high enough to place a jack stand.

[William F.]

Re: Jacking up C3 Front end or rear end in "one Shot"

Manual shows "on frame before front kick up " for front floor jack and "just in front of 3rd body mount on frame" for rear floor jack. Nowhere is jacking on rear ends of frame or under front A arms or front cross member or rear differential suggested.

[Kenneth B.]

Re: Jacking up C3 Front end or rear end in "one Shot"

Not to weigh in on the crossmember discussion but I always pop the hood, open the doors and pop the convertible top before jacking or lifting the car. I have a C3 as well.

Why would you do that to any Corvette especially a convertible that gets its body rigidity from the closed doors & hood. Not a C-1 C-2 C-3 or any other model.

[Gary R.]

Re: Jacking up C3 Front end or rear end in "one Shot"

Manual shows "on frame before front kick up " for front floor jack and "just in front of 3rd body mount on frame" for rear floor jack. Nowhere is jacking on rear ends of frame or under front A arms or front cross member or rear differential suggested.

That's how I have always jacked them up, one spot at a time. Doors cracked. However my friend always jacked his up at the diff since he had side pipes.

[Keith M.]

Re: Jacking up C3 Front end or rear end in "one Shot"

Why would you do that to any Corvette especially a convertible that gets its body rigidity from the closed doors & hood. Not a C-1 C-2 C-3 or any other model.

This is one I have heard but truly do not understand. The body is mounted to the frame in a number of places. The frame is a strong steel structure supporting the body. I am in early stages of my restoration...teardown phase. Car is up on jack stands (as been for many months) placed under frame just behind front wheels and ahead of rear wheels. I open and close the doors all the time. I cannot see from a structural stress perspective that an open door poses any risk. It would essentially have to bend the frame to do so. The alleged risk implies the properly supported frame is not strong enough to support the body without the doors closed. If so, same would be true of the car on the wheels on the ground. Weight of the vehicle is on the wheels which attach to the frame by A-arms and trailing arms thus requiring the frame to support the body. If the risk were real, opening the doors with the car on the ground would risk the car bowing in it's center.,,,exacerbated more so with a couple passengers sitting essentially directly in the center point. In a static situation I see no risk but remain open to being educated otherwise.