Lifts: 4-poster or 2-poster?

[Nova-Mann]

I am going to purchase a lift, and wondered what thoughts people had on the subject. A 2-post has more access, but when I do all of my frame and suspension modifications I would like to have the car on it's wheels when I am working underneath (loaded chassis). What has your experience been? I can store the car up and work below. Also, what brands?

[camcojb]

I am going to purchase a lift, and wondered what thoughts people had on the subject. A 2-post has more access, but when I do all of my frame and suspension modifications I would like to have the car on it's wheels when I am working underneath (loaded chassis). What has your experience been? I can store the car up and work below. Also, what brands?


I have an Eagle 4-post and a friend has a Backyard Buddy 4-post. Advantage is they can be moved, and ease of pulling up and lifting without setting the arms. Also less chance of the car falling off or sliding on the lift. The 2-post is better for constant tire/wheel removal like brake jobs.

Remember that you need a minimum of 6" concrete thickness and they recommend 8-10" for the 2 posts as all the load is on the mounts in the concrete. Standard 4" concrete is fine for the 4-post.

If you have 220 volts the 220 volt versions lift quite a bit faster than the 110 versions.

Jody

[Rick Dorion]

With jacking trays, I've been able to anything using my 4-post PerfectPark.

[Piet]

2 posts make me nervous... I have seen too many pictures of 2 posts that becam 3 posts....where the 3rd post was the front end of the car. You really need to anchor down the posts well. If you do... then they are fine.

Most 4 posts are moveable... I have seen pictures of a backyard buddy lifting a car in a parking lot. Beacause they are lifting the 4 corners... bolting to the floor is less of an issue.

If you are doing constant tire/wheel removal... consider a scissor lift rather than a 2 post.

Just my opinion.
-Peter

[justanova]

In my opinion the 2 posts, are much handier than the four post lifts, the only drawback i see is not being able to have the suspension loaded while working on it, but for anything like, wheels/braked/shocks/springs/rearends,etc... it is easier to remove/install stuff without anything in the way. As far as lifting a vehicle, just take an extra minute to check/double check where you put the lifting pads. I use a 2 post lift at my job and probably lift 5-6+ cars a day and i have been doing it for 3+ years and havent had a problem yet as far as a car shifting/falling. If you need the lift to do alot of suspension mockup type stuff, then the 4 post will probably be better but for general service work a 2 pos is the only way to go IMO

[ZZ430]

I agree with the great advice you've gotten so far.

If you only can have one or the other, I'd say go with the versatility of the 2 post.

They both have their advantages. They drive-on is of course faster and safer, even though I haven't had a car fall off a 2 post either.

I like the access to the under side of the vehicle with a 2 post. If you get the asymetrical design, opening the doors is a little easier.

The big disadvantage is, if you're taller than about 6 feet, you have to bend your head down to work under some vehicles even with a minimum 16 ft ceiling.

This is the hoist I use every day in my small performance shop.

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[Norm Peterson]

With the 2-post lift, concrete strength becomes more important as regards pullout strength of the bolts in the floor. If the CG of the vehicle on the lift falls outside the floor plates as seen in side view - either ahead of or behind, bolts will start to be loaded in tension, which is the load that is also trying to pull them out of their holes.

A related issue is that you may not be developing the required strength of a given bolt if there's a crack or a seam in the concrete that passes close to its hole. Concrete failure tends to be along the surface of a 45* cone (whose tip is slightly beneath the bottom end of the bolt) until the cone intersects a crack, possible broken or crumbled concrete from the drilling operation, or the cone associated with an adjacent bolt hole. This can also be a rather sudden failure. If there is specific knowledge about the worst case vehicle weight and CG position relative to the lift posts, plus the bolt pattern geometry, bolts, and concrete strength, it is still possible that safety of the installation can be demonstrated by engineering analysis.

While I can't legally advise anybody with specifics regarding their installation (since I don't hold a Professional Engineer's license) I have worked in a professional capacity with precisely this analysis for other items supported from plates bolted into concrete (and probably have enough resources handy to run an analysis for my own personal use).

And since I've personally seen professional lift installers ignore 'edge distance' during the major overhaul of a new car dealer's shop, do not assume that your installers will consider it either.

Be safe, guys. Get a local PE involved if you have any doubts about this whatsoever.

Norm

[Nova-Mann]

Thanks for the input. I knew that I would have to cut the floor and dig out a pad to be repoured with anchor bolts. I would hope that the lift manufacturer would give tech info about bolt size and concrete strength. I even considered building a ramp system to drive the car onto and securing the arms (2 post) so the car could have the chassis loaded, but I finally got some oxygen into my brain and came to my senses. Just what I need! Another project! And where would I store this disassembled engineering work of art. Dumb idea, eh? I learned the "eh" thing from some guys at our shop that grew up in the U.P. Any of you guys out there?

[Norm Peterson]

There may be something else. I didn't pay any attention to your location yesterday but happened to do so this morning. If your area is considered seismically active, there may be some requirements regarding horizontal loading.

Actually, if the floor is thick enough and of strong enough concrete, or even if a new pad is poured, it should be permissible to simply drill it for Hilti Quik-bolts. These things use tapers to expand a sleeve of sorts outward against the sides of the hole as the nut is drawn down tight. Used all the time in nuclear power plants.

You bring up a good point about storage, if it's not going to be a permanent installation. You'd also have to move it there, and the pieces to that stuff are kind of heavy.

Norm

[Nova-Mann]

Seismic activity is a big concern here. Just this morning on the news they were discussing the likelyhood of a 9.0 just off the coast of Oregon/Washington. As for the portable aspect, that would have been just for a ramp accessory that the lift would pick up. The lift itself would be stationary. I use Hilti products a lot in my work, and they do grip well, but I wouldn't feel secure unless I had J-bolts poured into a substantial pad. The rotational leverage putting a tensoin load on the bolt could be quite high. I am leaning toward the 4 post, but I like the open access of the 2 post. Guess I should flip a coin.

[Charley Lillard]

I have used both two and four post. I have a 4 post here at home and would never consider a two post. Two post you have to set the arms each time while a four post you just drive on. Most four posts now have optional rolling jacks that straddle the two rails and will lift the front or rear ends so you can have access to the wheels off or jacking the trans etc. Much safer for the home shop. It is hard to fall off a four post. With the ability to roll it around you can also take it outside to pressure wash under a car also. Two posts are handy for brake shops etc where the wheels come off most of the time but most of the time I am changing oil, cleaning, checking stuff, pulling trans, clutch etc. A guy near me has a couple two post lifts that they pulled out of a dealership that he wants to sell for I think 1500.00 each.

[Piet]

For my purposes.... I am looking at building my own version of a Kwik-Lift (http://www.kwiklift.com/). ... It does not go as high but is MUCH cheaper, portable, easy to store out of the way. I might consider full lift, but don't need to go that high most of the time. So this gets me 80% of what I need for 30% of the cost... not bad.

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[justanova]

I might consider full lift, but don't need to go that high most of the time

IMHO it is worth going with a full lift for the fact that you can put the car up and stand underneath it to do everything, no rolling on the ground on a creeper, getting you shirt caught in the wheels, getting stuck on the airhose, the bolt that you just dropped rolling under the creeper and you cant find it, having to get up and lay down everytime you forgot a tool that you needed, etc..... After working with a full lift at my work, I don't even set tire pressures on a car without lifting it to chest height to set them because its easier/faster to just lift it than drag the airhose around the car and have to bend down all the time, I think over time it will be easier on my back/knees.

just another couple of cents for everyone to consider.

[hotdog]

Whats the lowest celling height for a 4 post?

[Texas Bob]

Whats the lowest celling height for a 4 post?

I'm interested as well.

[Rubes]

I've got 10ft concrete to bottom of rafters, and would concider that the minimum. there are certain combinations of cars I cant put under/ over...like I can put my Trans Am (no motor) on top and fit my lowered Malibu wagon underneath, but my Xtreme S10 will not fit.

oh, I've got an Eagle 4 post.

Rubes

[kman67rsss]

My dad has a kwik lift and loves it. we didnt have the ceiling requirement as we converted his old kiln into a garage so he could build a hot rod. for the price it cant be beat.

[ahowudoin]

I have used both two and four post. I have a 4 post here at home and would never consider a two post. Two post you have to set the arms each time while a four post you just drive on. Most four posts now have optional rolling jacks that straddle the two rails and will lift the front or rear ends so you can have access to the wheels off or jacking the trans etc. Much safer for the home shop. It is hard to fall off a four post. With the ability to roll it around you can also take it outside to pressure wash under a car also. Two posts are handy for brake shops etc where the wheels come off most of the time but most of the time I am changing oil, cleaning, checking stuff, pulling trans, clutch etc. A guy near me has a couple two post lifts that they pulled out of a dealership that he wants to sell for I think 1500.00 each.
Where are you located? I would only go 2 post because I do side jobs, If you ever did timing belts on front wheel drive,you would to. leaning over the rail is a pain.

[Wildthing]

Instead of buying a new tranny I just purchased a two post lift two weeks ago. A few minutes ago I completed install and lifted my Camaro. Seems stable. I am leaving the Camaro on it over night at the lowest height to stress test it.

I went with a used lift that I found locally through Craigslist. It is a Rotary Two Post lift that is Asymmetric. Asymmetric offsets the post so the doors can be opened almost all the way (useful for working under the dash). See the pics.

The folks at Rotary sent me the installation instructions which were relatively easy to follow. The requirements are that the concrete floor be 5 inches thick or you pour two pads that are 4 foot by 4 foot. We just had to drill (10) 3/4" dia holes 4.25 inches into the concrete. The instructions are very clear (and easy). I can post the soft copy here if anyone is interested. 3/4 inch Hilti bolts (described in a previous posting bolt the lift bases to the concrete. The only problem encountered was that in two holes we hit rebar. We swiss-cheesed the rebar with a drill then chiseled out as much as we could. These two holes ended up slightly over-sized so we shot concrete epoxy into the hole, pounded in the Hilti's and let them dry overnight.

[vintageracer]

Two post lift for work/service on your vehicle and 4 post for storage/parking. Decide which is the MOST important use of a lift for YOUR needs and buy accordingly.

I like the 2 post lift since my reason for having a lift is work/service of my cars. I can lift the body off of frames and re-install bodies, lift cars that need the engine/suspension to be removed from the bottom, do suspension work much easier etc. There are LOTS OF THINGS you can do with a 2 post lift that cannot be done with a 4 post. I have PLENTY of storage space so a 4 post lift for storage was not a consideration for me. The ability to move a lift which is optional with a 4 post lift was also not a consideration for me.

The purchase of a lift ranks up there with the purchase of your first hydraulic jack so you could easily jack up your car. You wonder how you EVER did any work without one. A lift will easily become one of the BEST SHOP PURCHASES you will ever make!

Unless the ability to double park cars in one space is your MAIN goal, a 2 post lift is the ONLY WAY TO GO!

[scogin918]

The Simpson Stong Tie reps came to talk to us last night to talk to us about their new anchor - the Titan HD. No sleeve or epoxy required and no special drill bit. Whatever size bolt you need, that's the size drill-bit you use. http://www.simpsonanchors.com/catalog/mechanical/titen-hd/index.html
They said the bolt eliminates the cone effect and makes the area of base material surrounding the bolt more of a cylinder therby increasing the pull-up rating. And they are removable.


As far as 2 vs 4 post, if I had the room I'd be inclined to do one of each. Most garages around here have a combination to fit their various needs.

[shmoov69]

I just bought a used 2 post the other day for $1000. It came out of a mechanics shop when they bought a bunch of new ones. I haven't checked my concrete thickness yet, sooo...... Hopefully it will work! Also, since my ceiling follows the roof line with the ridge in the center, I may have to cut two square holes in the sheetrock where the posts are. Hopefully it will be a good buy!

[Norm Peterson]

Also find out what its compressive strength is. The weaker it is, the longer the anchors must be in order to develop sufficient strength, with the obvious implications regarding slab thickness. The Simpsonanchors site can be used to get some idea, but if the concrete was improperly mixed (too much water added, just to make it pour more easily) you won't even be at 3000 psi. For homeowner-mixed concrete, unexpectedly low strength can easily result regardless of what the bags might say that the mix is potentially good for.


Norm

[Wildthing]

Hey Shmoov69!

Congratulations. I installed my Rotary 2-post 3 weeks ago. So far I have had a 03 Mach 1 on it for a header-back exhaust install, a 04 Cobra on it for Cat-back exhaust install, and (right now) my '68 is on it with an all new TKO-600 already installed. One of the best purchases ever. While my car is on it...complete undercoat removal and replacement...something I never wanted to do laying on my back...

Sounds like you got a good price. What's the brand of it?

[shmoov69]

Hey Shmoov69!

Sounds like you got a good price. What's the brand of it?
I haven't got a clue!! It is still sitting in my friends barn floor 45 minutes from here! Hopefully it is all there and will go up easily and work! I have told myself that I will be kicking myself in the butt for not buying one sooner. Heck, I have pi$$ed that much money away before and have nothing to show for it. I thought the same thing when I finally bought an air compressor and air tools. This is after doing 4 eingine changes, suspension rebuild and a couple tranny's in the Camaro and a full suspension rebuild on a 80 Corvette that I used to have. :screwy: What was I thinkin!!!

[Rabidhamster]

I'm gonna further one of the things said many times over

for shop that does alot of maint type work.. a 2 poster can't be beat

for a custom shop a 4 poster drive on is a very good choice .. although as mentioned a 2 poster in a custom shop would allow you to take off bodies easily and roll the chassis out.

I've been designing in my head one of those kwik lifts for the shop... mainly becuase I don't really have the ceiling height for a full lift .. but I am thinking of one with casters on it so I can move the vehicle around. I do like the kwik lift for small shops cause you can use it like a frame jig too

I think it comes down to what YOU absolutely need to do with it.