Need some construction advice

[gregaba]

I had my 2 post lift installed 13 years ago and yesterday was lifting my Ranchero on it after installing a new windshield.
While lifting the car I had my hand resting on the post and it moved a little bit.
When I got the car up to the top I looked at the bottom of the post and the inside of the post was lifted about a 1/8 inch.
When I pored the floor I made the part of it that the post would mount to 36 inch's deep.
Kind of concerned about this and tomorrow I  will lower the car to the floor and tighten down the nuts holding the post to the floor.
I have in the past tightened these down and they were all ways a little loose after about 6 months or so.
Any advice to prevent this from happening again.
thanks
Greg

[cleandan]

Try to determine what is moving to allow the nuts to come loose.

If you keep tightening the nuts and they keep coming loose, something is moving.
The nuts are vibrating loose somehow.
The studs are either stretching or the threads are stripping.
The floor plate of the lift is crushing.
The stud is pulling out of the concrete.
The floor is shifting.
The ground under the concrete is moving in some manner.

I don't know where you live but this could be the result of freeze/thaw cycles.


Oh, and never rule out gremlins....specially if you have one parked on the lift.

[gregaba]

I am leaning to the idea that the anchor's are pulling out right now.
I will go out in the morning and tighten up the nut while marking the anchor and if the anchor is loose I will have to find a way to stabilize it or replace it.
It would be both the anchors on that side.
The concrete is not cracked and I can find no damage to it.
I did have some fluid that was leaking and it could have went between the concrete and anchor but I have never heard of that being a problem before.
I live in Oklahoma and we do have freeze conditions every winter.
That is why I pored a 3x3x3 foot area under the posts.
I don't think installing new anchors would be that easy and am just not sure how to fix the problem.
I am limited on where I can move the lift and unless I raise the roof in another part of the shop 10 feet I still would have to jackhammer out the floor and pore another base for the post's.
Greg

[machoneman]

If the studs are plain steel, construction grade, I'd guess they are stretching. May need to investigate studs used to anchor heavy shop machinery, presses, etc.

[gregaba]

Thanks
 If it is the anchors which I am sure the installer used the cheapest ones he could find then I will change out all of them for a better grade.
Greg

[Tunnelwedge]

What type of anchors?
There are really good epoxies that can be injected to tighten concrete anchors.
Also extra legs bolted further out help in tippy situations.

[Rory428]

Just curious how many anchor studs you have, and were they supplied with the lift? My 2 post lift has only been in for about 2 1/2 years now, (10,000 pound Atlas with symmetrical arms, and a floor plate to cover the cables, as my shop only has 11 foot ceiling, so not high enough for a "clean floor" version. I bought my lift new, and my concrete floor is only 5" deep, which was the minimum recommended thickness, and it has 5 anchor studs per side, that were included with the lift. When I drilled the holes in the concrete floor, for the anchors, I could feel the drill go thru the concrete, and into the dirt below. To install the anchor studs, it required several whacks with a good sized hammer to drive the anchor studs in enough into the holes, did your anchors fit tight like that? The instructions with my lift, said that the nuts for the anchor studs needed to be torqued to specs, and rechecked, and retorqued periodically, even the lifts at the dealership I worked at were supposed to be retorqued every 2 or 3 months. Although my hoist id rated for 10,000 pounds, the heaviest vehicle that I have up on it so far, is my 59, which is 3800 pounds without driver. My F350 Dually is about 6700 pounds, and I am hoping to put it on the lift this winter, but when I do, I will be keeping a close on the towers and anchor studs when I do lift it up.

[gregaba]

Rory
I have 8 anchors, 4 on each post.
The lift is an 9000 lb lift asymmetrical lift. Champion brand.
I had it installed by the company I bought it from as I was working at the time and They were suppose to be there by 1 pm but didn't show up until 4 pm. I got home while they were finishing up.
They left me no instructions.
They did hammer in the anchors real good and I had no cause for alarm. I have checked them every 3 to four months and have had to tighten one or two every time.
The anchors they used looked like the standard 3/4 inch ones you would by at Lowe's etc.
So far I have been well satisfied with the lift as it allowed me to continue to work on my junk after my body said hold on.
Tunnelwedge
i was on the web this afternoon and found some epoxy cement made for that problem, if that is my problem.
I don't have any tippy situations yet but won't rule it out in the future. I made sure the concrete was 3 feet thick where the post are mounted and they gradually thin out to 6 inches at the outer edge of the floor.
I will know more in the morning when I can lower the lift and see what is going on.
Greg

[preaction]

The fasteners  are held in by friction and the strength of the concrete, 5" of 4000 psi concrete is all that is needed 30" is  not necessary also drilling through the floor to dirt is not how  carbon steel expansion anchors are installed correctly reading the directions for this type of installation should be done. If installed correctly and torqued properly Hilti brand wedge anchors will not need to be retorqued this has been my experience over the past 24 years for my lift and from having installed thousands of this type of anchor. IIRC only 1/2" to 3/4" of the anchor should be above the top of the nut any more and you don't  have the rated holding power of the anchor.

[gdaddy01]

I just watch a good u tube video on this very problem  good to maybe get some ideals.

[Joe-JDC]

Do you have a tie bar across the top?  My lift has a top bar that keeps the lift from moving inward with weight.  Been using it for 22 years without any problems.  Joe-JDC

[Joe-JDC]

This is the tie bar over the side posts.  It clears a F-150 Super Crew with hood open.  12' ceiling.  Joe-JDC

[gregaba]

Looked at several utube videos on the cure and think I will switch out the loose ones for the epoxy fix.
I don't have the top bar as at the time I bought the lift I though it would interfere with how high the car would be able to rise. The roof is 13 foot high.
Funny thing is my post is leaning to the outside and not to the inside.
I bought the bottom bar and am considering adding a top bar after I get the anchors fixed.
It should be simple to do, I will just need to get a little help to hold up one end while i tighten the other side.
Greg

[Rory428]

If your towers are leaning, either in, or out, you likely need to shim the bases to make them vertical. My shop has floor drains, so the floor has a bit of a slope to direct any water towards the drains, so I needed to shim the inside edges of the bases to prevent the towers from tilting in. These shims were included with the lift, and were inside the box of hardware that came with the lift. My lift does not have an upper bar, as it has a floor plate and the cables run below the plate,so the top is wide open. I have considered fabricating an upper bar, but that would likely mean that it would prevent most of my vehicles from being able to go all the way to the top, as the roof could hit the bar. But, to be honest, I would be more concerned about having 10 feet or so of vehicle hanging out of either end of the towers, and the towers falling either forward or backwards. That is why I usually use a tall pole stand to prevent the car or truck from bouncing or flexing on the hoist, especially when removing heavy components like a transmission or rearend.

[gregaba]

I will have to check the level when I start on it. I had it installed so don't know if shims were used or not. I all so have a sloped floor for drainage.
I have used pole stands for years even when I worked in dealerships and for independent shops. Everyone used to make fun of me for using them but when you get 4000 pounds bouncing on the lift then it makes you think.
If I add an upper bar i will loose about a foot of height I can lift my vehicles so I really don't want to do that but I might have to.
Greg