4 post drive on lift questions and options
 

So my new garage will have a "post tension slab" cable system in the concrete and any drilling of the concrete floor will void the warranty of it. I am struggling with not only finding the exact locations of the cables before the concrete is poured so that I do not damage them if I decide to install a two post lift vs just bowing to the pressure from all sides and putting a 4 post lift in that will not require drilling the floor.

This thread is more about those said 4 posts lifts...

I'm looking at this lift. http://www.gregsmithequipment.com/At...-Sliding-Jacks

It is long enough and has the capacity to lift my ex-cab long bed truck and also lifts high enough for me to walk under it without banging my noggin. It also comes with two hydraulic RJ 35 sliding jacks with arms that will slide out to get under the real lifting points of most vehicles. Does anyone have experience with using these jacks in a real world scenario and if so, do you like or dislike them and why?

All the way down they are 3.5" tall which should be low enough for me to get any street driven car over them with ease. They have locks on them which will allow them to serve at jack stands if the vehicle needs to be off the tires for an extended time. It all seems good and sounds like a decent alternative to the two post lift that I have and love now...and even has some features that will be better than my two post (like being able to get the lift perfectly level for suspension setup purposes).

Buying this 4 post lift eliminates some huge hassles in regard to drilling my new floor, I guess I'm just trying to make sure I'm not creating more (different) hassles in using it once I get it installed. Space is not an issue, the new shop will have way more room than I'll need for any lift I choose ( :D ). I am picking electrical outlets this morning so if I need a 30 amp 220v for the two post, now is the time. That's the other nice feature of this 4 post lift...it runs on 110v.

Any thoughts from those that have used one similar to this?

http://www.gregsmithequipment.com/Pr...OJACK35-03.jpg

http://www.gregsmithequipment.com/Pr...OJACK35-45.jpg

http://www.gregsmithequipment.com/Pr...OJACK35-44.jpg

http://www.gregsmithequipment.com/Pr...OJACK35-39.jpg

http://www.gregsmithequipment.com/Pr...OJACK35-38.jpg

GPRS if you want to locate the cables after you pour. Ground Penetrating Radar system. You can call a local concrete cutter or Concrete coring contractor and they can get you to the people who can perform this. We do this all the time when building Hi rise buildings when a contractor misses a location in the slab.

http://www.groundpenetratingradarmis...s-City-MO.html

4 Post
 

You can buy a 4- Post lift that does not need to be anchored to the floor. Mine has casters you latch on it to move it if needed. It has been free standing and in use for 20 years. Never had a problem.

Yes. ^^^^. A pricey service, but if u nick one of these cables when drilling the holes for the lift, u DO NOT want to know what happens. I've seen some knarley videos (cutting a kitchen in half, another a person in half (older you-tube adult only access, mainly construction accidents where people were seriously injured or killed.)

Have the floor x-rayed after installed and compare that with current shop notes/drawings for cross reference.

With caution, mike

The builder will NOT provide any measurements or pics of said cables before the pour. They are VERY careful about this... They also will not allow anyone but me on site between cable install and concrete pour and I'm not sure I'll be able to be onsite that one certain day to view the cable layout.

Above and beyond that...drilling the floor automatically voids the warranty, no questions asked.

As much as I like a two post lift, I think my best option may be to just go with the big bad 4 post lift with two sliding jacks.

I've used smaller more simple drive on lifts in the past and they were a PITA to do any suspension work on. Way too hard to get bottle jacks on the jack trays and under the car's lifting points and the ramps were always in the way. Hopefully these hydraulic jacks solve that irritating issue.

My question is why that style floor ....why not a floating slab ....i.e footings around perimeter and then the concrete floor aka slab

So the floor hasn't been poured yet? Just build some anchor plates with the bolts already in. Just align and stick in the slab before pouring.

I have a similar 9000 pound tall wide four post lift. I also have a two post lift. I would take the two post lift over the four post by a wide margin. The ramps on the four post are quite wide and always seem to get in the way. It is also slower to raise. I use the four post to measure driveshaft lengths and driveline angles etc and also to do oil changes. Everything else is done on the two post lift.

Your builder should be able to share the slab drawings to locate the cables. If not they are easy to locate if you look for the grout plugs on the side of the slab.

Don

I'm curious about the use of that style floor as well, not common in my part of the world....commercial hi rise yes, but not residential. Hmmm.

As far as the lift, I got nothing. :)

I have had a 4 post lift for years and have that exact sliding jack platform. It is awsome. Bought a two post lift a year ago and hardly use it. I prefer the 4 post. Just drive on and lift. No crawling on the ground all around the car getting the 2 post arms in just the right spot. a 4 post can also be rolled outside if your door is high enough if you want to pressure wash under the car.

We are having a production style builder build the new house and garage in a subdivision and there are NO exceptions to the way they build. Basically it's their way or the highway. Thing is, we like it because we found about 97% of everything we wanted with this builder and everything else is going very VERY smooth so far.

This is what they do, the post tension slab...and there is no way around it. I'm just trying to do the best with what I have available.

The Super did take me out on a job site Tuesday and showed me a similar garage that is formed and has the cables in place so I could look to see them before the pour and he did say I'll be able to see the one end where they grout over the cable hole...but not the other end. He just stressed that the cables might move while it is being poured and the ramifications of nicking a cable while drilling are massive... They won't even let anyone but myself onto the job site to look at the slab area the day before it's poured, only the homeowner is allowed onsite (for safety reasons).

I understand why they are like this and am okay with it...I just need to figure out if it's worth it to me to take the risk of locating the cables after it's finished and drill the floor (completely voiding the slab warranty) just to have a two post vs a 4 post lift.

This is a just about identical slab as I'll have, the side I'm looking at here is about 15' wide and 48' deep. The cables are on roughly 4' centers here. Each layout would be different though just based on how the guy that installs the cables that day does it.

https://photos.smugmug.com/Other/i-3..._150950-X2.jpg

That all sounds fine and dandy Craig, and I agree... But the first problem is I'll most likely be 1200 miles away the day they get ready to pour. Second problem is...no way will they let me do that. This company is SO strict about following their procedures, they do not vary on ANYTHING. We get exactly 3 what they call ZQ orders with are special "off the books" requests and we've used all 3 up already.

Please understand, I'm getting my dream house and shop here...it's going to be cool. No way am I letting the little lift issue screw the rest of this up. :D

That's what I wanted to hear Charley, from someone with first hand experience. My only concern was the jack part being low enough to stay out of the way but it seems like it is and that won't be an issue on any of my street driven cars anyway.

How was the drive on lift to use the last time you pulled the suspension apart on something parked on it? :D Did the ramps get in the way at all?

The ramps also serve as a place to put all the parts you are taking off.

Glad you got the answer you wanted to hear. Since retiring (Thanks Greg!) I am out in my shop 6 or 7 days a week doing a couple of frame offs per year. I can tell you there is no way I would give up my two post for either of my four post lifts. Too slow and too awkward to work around in my experience. I guess it comes down to what you used first and how you developed your working techniques around the limitations of the lift.

And yes the four post makes an awesome wash rack. I set one up outside under a large 12' high cover for just that purpose.

Don

:trophy-1302: Two posts for folks that WORK on cars. 4 posts for those than Tinker.

With that slab, I'd stick with the 4 post. You can't have it all.

I appreciate that Don. I agree that it is based on what you are used to working on and how you will be using one. While I love my two post lift, there are a few things about it that make me think a drive on would be better for me at times. For instance, I can not get my lift arms to lift equally on both sides, so the pass side of the car is always a bit higher than the driver side. This doesn't affect you while doing any suspension work on the car, but for ride height setup, corner balancing, alignments, etc it's a huge PITA. I had to build crib stands and level each of them and set the car on those to do any suspension setup work whereas with a level drive on lift it's just drive up and go.

I imagine the raising speed is related to the 110v motors vs the 220v. I've dealt with the slower raising speed on 4 posts before and don't think that will be an issue for me. If anything, the very slow lowering speed of the two post vs the fast drop of the 4 post might make up for that. Unless my 7,000 # truck is on my 2 post, it is VERY slow to come down.

My main concern was how the two sliding jack setups are to work with. If they got in the way constantly, cars got hung up on them and they were hard to get the lift pads in the right areas, that would be a pain in the arse. I thought they looked like this wouldn't be a big issue but wanted to be sure. I KNOW using bottle jacks on the jack trays of the regular drive on lifts is a huge PITA. The only way I would even consider a drive on is to get one with the two sliding powered jacks.

My shop floor will be sloped front to back but should be pretty level side to side, so all I'll need to do is work out a pad to put under the back legs to get the lift level. That shouldn't be too difficult. I can probably work on some way to attach those pads to the floor (adhesives maybe) and have bolts sticking up out of them to just secure the legs in place. This way I can still use the caster kit to roll the lift to a different spot if necessary. Most likely I won't but it's nice to have that option.

It's also nice that the drive on ramps store in between the big lift ramps, more than once I've walked into the ramps hanging off the back of our old lifts...and walked away bleeding.

I cannot drive my wife's 69 Camaro onto my four post lift if the jack is at the rear of the lift. I have to push it forward so the car will clear. Her car is lowered on Ridetech level 2 suspension. Not a huge deal.

Each post has a height adjustment so you should not need pads to level the lift.

Hope you enjoy the new shop.

Don

Sweet, where exactly is the height adjustment? More specifically does it adjust the locks so they end up being level when the ramps are lowered down onto the locks?

The shop (and house really) is going to be awesome, I can't wait. Being in the Southwest vs the Midwest will be the #1 huge upgrade weather wise, but also basically having everything I currently have on my 11 acre lot now with 4.5 acres of grass to mow on a .8 acre lot in a gated subdivision with zero grass to mow PLUS a pool...is going to be sweet.

Here is a picture that is pretty similar to how our house and shop is going to end up looking like.

https://photos.smugmug.com/Vista-Mon...JRxzg77-X2.jpg

Only difference is I'll have a 9' tall door next to the 14' tall door on the front of the garage instead of the windows like this one has. The shop is 31x51 clear open span on the inside with 16' ceilings. It also will have a 14' tall door on the back side and a 50'x50' gravel area behind the shop to park trailers and whatnot which will all be inside a 6' tall concrete block fence.

The shop interior will be insulated and completely sheet rock finished and have one full bath in the back house side corner. Other that that it'll be a blank canvas for me to start over in. I plan to put the lift inside the 9' door area and my office will be built between the lift and the bathroom. The whole other side of the garage will be open to store my RV and whatever else I need to arrange for.

There is a nut on top of each post that adjust the height of the locks. Easy to do.

Don

Lance, out here a slab warranty is one year. Shoot...most guys on here are pros at voiding a new car warranty. I understand that a house is a far greater investment, but it's just a slab. Take pictures the day before the pour, and measurements. You'll have no problem missing those cables being as how they are on 4' centers.

If by chance I wasn't 1200 miles away that day, I'd certainly do that! and they won't let any of my "representatives" even on site either.

Heck, they made me wear a hard hat and a vest just to walk on the neighbors lot shown above (and made my wife stay in the car with her open toed shoes on).

Charley and I have discussed this 4 post /2 post dilemma for awhile now -- he likes the 4 post -- I wouldn't have one. I think it's one of those things like a golf swing.... everyone has pluses and minuses..... I had a drive on for about 2 weeks before it went bye bye.... seems everything I wanted to do -- the ramps were in my way.... I don't need the ramps to lay parts or tools on -- I use the big Rubbermaid 4 wheel carts for that....

I do agree with Charley about crawling around to put the arms where they need to go.... but I have these "ERGO mats" (I think that's what they're called) on either side of the lift and just kneel or lay on them as needed.

I just had a Rotary Lift (SPO-10) installed in the track shop.... mostly I'm changing out wheels - doing oil changes - and replacing brake pads etc.... and I like the ease with which that is done on the 2 post Asymmetric (that way you can open the doors wide open and not hit the posts).

Would a metal detector surveyors useto pick up the cables. We used them on jobs to pick up water line and power lines? you could have him make a box as a form and leave the concrete out of it, Then you dig down at each box and pour them like a footing with your bolts located. Just a couple of ideas.

This house is being built by a production style builder that builds 1,000s of houses a year. They have their systems in place to make sure everything goes smooth and they do NOT vary from their systems at all. Being concerned about 1 home buyer wanting to out a bolt down lift in one of the homes they are building doesn't even blip their radar.

If I lived there while it was being built, I might have done things differently...but for my situation, this the best way to get everything I want. I'll just have to deal with this lift issue best I can.

I too have had that exact slider center jack and 4-post for over 20 years and am satisfied. I've been able to accomplish what I wanted.

Lance,
I have that exact bridge jack on my 4 post and they are great! In fact I purchased it from Greg Smith. But I'm not sure I would want two of them. I think two jacks would take away a lot of work space under the vehicle and they are very heavy to move on and off the lift. I have to store my jack all the way to the front of the lift in order to get the car on the platform. I also had to build a riser for the front wheels to set on in order to get clearance under the car for the jack. The riser is nothing more than a 3ft length of 2x12 wood setting on the platform with a 2x4 bolted laterally on top to act as a wheel stop.

Don't stress yourself worrying about drilling holes in that new floor. Buy the 4 post with the castors and you can move it anywhere you need it. I would just add that my 4 post is not bolted to the floor and we had a 6.9 earthquake here in VA a few years ago. Dust Off was stored on the lift about 7ft in the air at the time. The car and lift were totally unaffected by the shaking. Unfortunately I can't say the same for the house foundation. Bottom line is that I could not have built Dust Off without the lift and jack.

Thank you Steve and Rick for the input, you guys relating your hands on experience helps make this decision a bit easier.

Are there locks on those jacks? Like can you lift the car up off the ramps and set it on locks inside the jack? Or will they just bleed back down like a bottle or floor jack if weight is left on them for a long time? They are hydraulic right, they tie into the hoist pump? To remove one you would have to take the hydraulic line loose correct?

Maybe having just one in place might be a better option. If I needed all 4 tires up I could just lift the front of the car, put jack stands under the lift points and ramps then move the jack to the rear to lift it up.

I'd really like to see one in operation first hand before making this decision. Thankfully I have until next January at the earliest to do so.

They are manual pump jacks, they do not tie into the lift hydraulics. No locks on mine. They are very heavy. You install them and leave them. Just slide them back and forth. The long lift you are buying can easily accommodate two jacks.

Don

They have automatic locks so no need to worry about it bleeding down. As you are jacking up you will hear the locks clicking and can see it working. I just have one on my hoist and love it. Hellfire and other cars clear the sliding jack with no problem.
I think in the post above he is misunderstanding your question about locks.. Once it is setting on the locks you need to jack it up slightly in order to unlock it.

Okay, so manually pumping a jack is not my preferred method!! :D

After a little digging I found this little gem which will convert any manual hydraulic jack pump to an air operated one.

http://www.gregsmithequipment.com/Ai...t-w-auto-oiler

I then found another lift supplier that sells a RJ 45 jack that lefts 4500# and comes with the air over hydraulic option too. It appears these newer versions do have locking tabs as well. The RJ 45 also has ball bearing wheels instead of just plastic sliders that make it easier to roll the jack to and fro...

I'll keep digging and shopping but thanks for sharing the details on these. I think with enough bells and whistles I can really set a 4 post lift up to do what I want it to do easily.

I need to look more carefully at the commercial 4 post lifts as well, they've got 220v pumps on them which I'm sure will go up faster but they also cost considerably more.

The manual jack is simple. The pump is simply a porta power. I would not bother with the air setup and it is just a hose you would need to bother with. The ports power jack really is easy and quick.

I converted my engine hoist to air over hydraulic..... best thing I ever did!! It became less "bouncy" with a load... was smoother... and was easy to fine tune in lifting. That wouldn't apply to these four post lift options - but it sure was slick on the engine hoist.

I agree the air assist is not necessary. The bridge jack features a lock mechanism which will allow you to take the load off the hydraulic ram for prolonged raised storage. I also think the RJ45 is overkill because you will only be lifting one end of your car at a time. The 3500# RJ35 is more than capable for your intended use.

Lance,
Take a look at this thread where I described the LED lift lights I installed on my lift.

https://lateral-g.net/forums/showthread.php4?t=48550

another reason i like this site, I learned allot just reading this one thread...

That is going to be a nice garage Lance, I hope your challenges all work out.

Joe

I guess I can put this one to bed...

My Realtor (she rocks BTW) went out last Saturday with a tape measure and a camera and laid out where the tension cables are behind the 9' door part of the RV garage...and the results aren't good for wanting to drill to install a two post lift.

In this picture the black lines with arrows are the tension cables, purple lines are measurements from bottom and right walls.

https://photos.smugmug.com/Vista-Mon.../i-GCqHbJK.jpg

I would want a two post lift with 108" (9') in between the posts which is the same width as the door. The cable on the left side of the door running up and down (North & South) is right in the way of where we'd have to drill.

To get around that I'd have to move the lift either too far to the left or too far to the right and neither is a good fix.

So it looks like we'll go with the commercial grade four post lift after all.

Here's a picture of the actual cables which are hopefully covered in concrete by now.

https://photos.smugmug.com/Vista-Mon...hJrW4x4-XL.jpg

How big is the base (or foot) of the 2 Post?

They are 19" wide on my current 2 post...

9' between them then almost 2' on each side outside of that to be safe...

https://photos.smugmug.com/Other/i-C..._100000-XL.jpg

I don't think you want to center the lift on the door. Not enough room on the right. I think it should be offset to the left in which case it could be centered on the cables that are 8' apart.

Don

Yeah...I've thought about being too close to the East wall as well. What you say makes sense but still it only leaves a 6" window on each side of those cables 8 feet apart.

Then one has to decide how deep in the bay to put them. Between the 9' and 13'5" cables from the door would be kind of close to the door, whereas it seems 15' from the door might be too deep in.

I think I gotta see it in person and play with it a bit before final decisions are made. At least I have a pretty good idea of where they are at now.