2 posts lifts--should I worry?

[viperdrummer]

I have another Viper on the way. I already have a 4 post Rotary lift in my garage and would like to add a 2nd but having 2 4 posts lifts will overwhelm my garage.

My dealer is suggesting the Rotary 2 post. Every time I look at it I have this image of my car hanging off the side or somehow getting off kilter. I have even heard of cars having to be rescued at dealerships.

One of my cars might spend weeks atop the 2 post and I really wonder whether it is a good thing.

For those with 2 posts--have you had problems? Should I be concerned ? Thanks

 

[fastmd]

Get the COMMERCIAL 2 POST ROTARY, you will have no problems. It is 220v and there is no comparison to the residential 2 post and 4 post lifts. I have 2 residential 4 post lifts and the Commercial 2 post. However, it is much larger and weighs alot more(concrete thickness will be an issue).
Good luck.

 

[Sneaky Pete]

As long as the car is on it properly and it's sitting on the locks, I wouldn't worry about it at all.

 

[nutkees]

Got an 2=post rotary lift in my garage en always got one car on it. Never had any problems with it.

Just make sure the concreet is thick enough so the 2 posts cant come together when you jack the car up. They will if not properly installed. I also put in a thick iron wire between the post en my garage wall. Just to be sure.

It's a lot easier to work on a car then on a 4-post.

 

[Martin]

Two posts are the way to go if you have a garage floor that can handle it. Many older houses have concrete slabs that are only 4" thick, and often the older concrete has degraded/cracked and isn't as strong as today's five or six-bag mix (and 6"-8" slabs). In CA (as usual the most anal of all states), some installations of 2-post lifts requires an engineering review of the PSI strength of the concrete, as well as the thickness. They'll drill a core, and bring it to the lab to see how much pressure it can handle. That failure strength has to be higher than what the two-post manufacturer calls for. Not sure, but I think it has to be 5000 psi concrete.

If you have any doubts about your garage slab, you might have more peace of mind with a four-post. But, if you do the engineering analysis of the slab and it comes out strong enough, you'll be a lot happier with the 2-post.

 

[Phun70]

Ditto to all that. I trust my life to a two post lift every day, and I've never seen one fail in my 20 years of turning a wrench. I can't say that for a four post lift though, I've seen several of them fail. I would make sure that the concrete is thick enough and most of the lifts call for between 3000 and 5000 psi concrete. Thickness is the most important factor. I installed all my hoists myself, but I would recommend that most people have them professionally installed. Lift the car in the right spots, and then lay it down on the locks, you won't have any problems whatsoever, and it's tons easier to work on a two post versus a four, much better access!!

 

[past ohio]

The problem I have with the 2 poster, is the suspension just hangs there all the way maxed out and the wheels dangle down....could be ******* the joints some...also important to check the actual thickness of the garage floor, some builders are known to get rid of their pop cans before the garage pour....I didn't like working on a car under a 2 poster and feel safer under a 4 poster....that is my likes, and my $.02....

 

[Martin]

I trust my life to a two post lift every day, and I've never seen one fail in my 20 years of turning a wrench. I can't say that for a four post lift though, I've seen several of them fail.

It's the way they fail that makes it scary... I've seen a two-post fail because the user had the car not centered right, and the whole thing started to tip when he was jacking the car up. The bolts were pulling right out of the concrete. That was undoubtedly due to installing it on a bad concrete pad, though. Concrete is much less strong in tension than it is in compression, so if you have the car off center and there is a bending moment at the base, it can get scary fast.

Four posts tend to fail mechanically more than structurally, at least in my experience. Those four posts need to be installed really well when bolted down. If the posts aren't perfectly parallel, and all on level, even concrete, they can buckle or go off track. Then you're stuck. I've never seen them fail because of a concrete failure, though. They apply a pure compressive load, and they're really safe from that standpoint.

Either type of lift is scary in an earthquake. I saw one setup buckle and fall during the '89 CA quake. If you're not in earthquake country, that's not so much of an issue, though...

 

[hemihead]

The problem I have with the 2 poster, is the suspension just hangs there all the way maxed out and the wheels dangle down....could be ******* the joints some...

I wonder about the suspension being un loaded for a period of time when using a two post lift for storage. I have a four post lift and I can see why a two post is better to work on but it seems that a four post is better for long term storage.

 

[Viperless]

I wonder about the suspension being un loaded for a period of time when using a two post lift for storage.

Two posts lifts are not meant to be used for storage!

 

[SSGSNAKE]

Not recommended. I have two four post. I was going to install a two post and Rotary told me not good for the car and not good to store a car on for a long perior of time. also every thing just hangs but that is no diffrnet than putting a car on blocks if you take the weight off for the winter. Just my input. I am going to put another 2 post in some day to work on the toys.

 

[mjorgensen Woodhouse]

Very much agree that a 2 post for storage is not the way to go, suspension bushings will hate it.

 

[Black Moon]

I have a 2 post and love it. You can do so much more on it. If you work on it get a 2 post. 4 posts are great for storage. My lift only required a 4" slab. I made it thicker (12") when we poured but everything I read says 4" is fine. The bolts only have about 4" of grab so I'm not sure a thicker slab isn't just overkill. I agree that storing on a 2 post isn't good although mine has been on there for a week at times and never any issues. I bought an American Lift Model tp9kac for $1,450. Dealer had one in stock locally so I picked it up and installed in one evening. Easy to do with 2 people and a chain hoist. I've had tons of cars and deisel trucks on mine and it hasn't even creeked once. Great lift for the money.

 

[Viperless]

If I have to leave my car on the lift overnight and the tires are off, I will lower it down to the first lock or let the arms rest on wood blocks.

 

[red heat]

If I have to leave my car on the lift overnight and the tires are off, I will lower it down to the first lock or let the arms rest on wood blocks.

that's the whole key to storage on a 2 post lift. let up on the hydraulic pressure so the safety latches grab. at that point. the car can stay up for as long as you need it.

 

[Jerry Dobson]

I have both and use them seven days a week. The four post is safer. Many mechanics have dropped cars on a two post lift because of weight shift, i.e. removing or installing a major component.

Concrete requirements for a 7,000 pound Rotary brand two post lift is 3,000 PSI at 4.25” thickness, basically a residential garage floor. Floor anchors are to be initially tightened to 150ft pounds. If you can’t achieve that amount of force, you must replace 4ft x 4ft section of concrete under the posts.

It takes much longer to position and lift a sports car on a two post vs a four post. They set low and you must take your time. You just drive on a four post lift. If you buy a two post lift, please get a lift with three stage arms and RA spin up lift pads. I hate using a standard two post lift without these upgrades.

The first thing I noticed with this post was “Ford GT”. Ford recommends using a four post lift. Lifting a GT on a two post lift is not fun. The rear subframe creates all the weight in the rear. With a asymmetrical lift, the weight is shifted back 30 degrees to begin with, then lift the car. If someone sneezes, you will see the front end reaching for the sky.

I use my 2 post lift WAAAAAAY more than my 4 post.

For most Service = 2 Post
For Storage/oil changes/transmission work/rear end work = 4 Post

 

[viperdrummer]

I have both and use them seven days a week. The four post is safer. Many mechanics have dropped cars on a two post lift because of weight shift, i.e. removing or installing a major component.

Concrete requirements for a 7,000 pound Rotary brand two post lift is 3,000 PSI at 4.25” thickness, basically a residential garage floor. Floor anchors are to be initially tightened to 150ft pounds. If you can’t achieve that amount of force, you must replace 4ft x 4ft section of concrete under the posts.

It takes much longer to position and lift a sports car on a two post vs a four post. They set low and you must take your time. You just drive on a four post lift. If you buy a two post lift, please get a lift with three stage arms and RA spin up lift pads. I hate using a standard two post lift without these upgrades.

The first thing I noticed with this post was “Ford GT”. Ford recommends using a four post lift. Lifting a GT on a two post lift is not fun. The rear subframe creates all the weight in the rear. With a asymmetrical lift, the weight is shifted back 30 degrees to begin with, then lift the car. If someone sneezes, you will see the front end reaching for the sky.

I use my 2 post lift WAAAAAAY more than my 4 post.

For most Service = 2 Post
For Storage/oil changes/transmission work/rear end work = 4 Post

Very good post, Jerry (Mark J also) My installer called me back yesterday and said as much as I like to sell 2 posts I cannot in good faith sell you one for storage. I likely would have put the Caddy on it--no way the GT. But in any event, looks like I am headed to a new garage.

I do remember the installers, when they were setting up my 4 post telling stories of making emergency runs to dealerships to catch "hangers" off of 2 posts. Thanks all

 

[treesnake]

2 post?.... 4 post?....

That's too many posts......

 

[v10enomous]

I would think those cross supports impede the ability to work on the car...

Can you drive over those braces on the floor if you have to ?

How do these compare in price to a 2 or 4 post ?

2 post?.... 4 post?....

That's too many posts......

 

[02 Graphite GTS]

After seeing Treesnakes single post and emailing him, I too bought the BendPak single post lift.

It is ideal for my garage layout.

As far as working on the car, the center panels come out and it is easy to do things like oil changes and other simple things.
I also have a BendPak 2 post lift and that is the way to go if you want to work on your car.
Aside from the issues posted by others with storing a car on a 2 post lift, remember that what may/might drip from the car on top will end up on the car that is stored below it.

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[C.Hermsen]

2 post?.... 4 post?....

That's too many posts......

Holy F-ing awesome!

How does that one post being off-centered hold the weight of a 3k lb car?? That's mind boggling!

 

[past ohio]

The single lift looks like the beam is bending into the floor, maybe the shadow on the wall mAKES IT LOOK LIKE IT IS LEANING....The single posts are expensive and I think that a 4 poster lift almost fits in the same footprint....I would feel safer working under the four poster, and not have that big structure on the floor to trip on !! ????

 

[Swanny]

I have another Viper on the way. I already have a 4 post Rotary lift in my garage and would like to add a 2nd but having 2 4 posts lifts will overwhelm my garage.

There are a couple four post lifts out there that are wide enough to hold two cars on top (and then two can park underneath). Not sure if that would help your space problem since it eliminates having a post in the middle of a two stall garage.

 

[jcaspar1]

I have a 2 post and love it. You can do so much more on it. If you work on it get a 2 post. 4 posts are great for storage. My lift only required a 4" slab. I made it thicker (12") when we poured but everything I read says 4" is fine. The bolts only have about 4" of grab so I'm not sure a thicker slab isn't just overkill. I agree that storing on a 2 post isn't good although mine has been on there for a week at times and never any issues. I bought an American Lift Model tp9kac for $1,450. Dealer had one in stock locally so I picked it up and installed in one evening. Easy to do with 2 people and a chain hoist. I've had tons of cars and deisel trucks on mine and it hasn't even creeked once. Great lift for the money.

Will the arms fit under a Gen II without jacking it up first?

 

[v10enomous]

A
Aside from the issues posted by others with storing a car on a 2 post lift, remember that what may/might drip from the car on top will end up on the car that is stored below it.


Good point about not having drip trays on a 2 post. I'd say that's a showstopper in terms of storing another car below.

 

[02 Graphite GTS]

The single lift looks like the beam is bending into the floor, maybe the shadow on the wall mAKES IT LOOK LIKE IT IS LEANING....The single posts are expensive and I think that a 4 poster lift almost fits in the same footprint....I would feel safer working under the four poster, and not have that big structure on the floor to trip on !! ????

With nothing on it, the post is plumb. The lift is and does "lean" with the weight of the car. It is a bit unsettling at first.
I talked to the BendPak engineers and they say that it is designed to lean as much as 1 1/2". With the ACR up there it leans 3/4". I have done work on the car with it up there, essentially park 2 cars under it, and we have had multiple 5.0 or greater earthquakes with no issues.......yet.