Project Backyard Shop: Installing a Lift

In reply to Austincrx :

IIRC 4" is the minimum thickness for this lift.

I have a Rotary Revolution 2-post (made by Direct, or Forward lifts; it's all a sticker game), and it called for 4" slab.  Most hoists seem to require minimum 4".

My 10k Bendpak two-post calls for 4".

Austincrx said:

What was the thickness of the garage floor pad that was required for this lift?  I have access to a used version, but I'm not sure if my 4-inch thick garage floor will be enough to support the 2-post structure, and I don't have the room for a 4-post.  22ft. deep garage is only barely enough for my 20 ft long truck, let alone a 4-post lift that will accommodate it.

 

thanks!!

For what it's worth, I hang one end of the car off the edge of my four post, depending on what job I need to do. Long as the lift can safely support the wheel base of the vehicle you're putting on there, I would be comfortable under it. NOW... disclaimer time, my lift is a 7k pound rated capacity, and I've never put a car heavier than 4k on it.

I would consult with a reputable lift manufacturer such as Bendpak, Ranger, those sorts of folks, see what they have to say about your situation.

Keith Tanner said:

My 10k Bendpak two-post calls for 4".

That's interesting, most of the two posters I looked at all called for a 6" slab. Or... perhaps it was more the psi of the concrete that was more critical, I forget now, it's been a few years since doing all my research.

The installation instructions for one of my Rotary lifts (found online) had info on slab requirements including minimum size and thickness if cutting out and replacing the slab locally.  My assymetrical lift, bought from the Ford Rouge plant, had an extra 6 inch wide plate welded to the base for both additional mounting studs and to get the load spread over a greater area.

How's the lift holding up? Have you guys had anything wider on it like a C5 or C6Z06? I'm curious to see how the lift arms will line up with the jacking points and if they'll fit under the car.

So far so good! 

I've had all kinds of stuff on it, including full-size trucks and a new handicap van. The wide stuff is a tight fit, but does indeed fit. 

We had a surprise when we purchased and installed our lift. When to the US distributor for the brand we bought and ordered/paid on site and trailered it home (30 miles - lucky us).  We knew we were a bit ceiling limited so compromised on a bottom cable tray model that was a tad shorter than the ceiling. Surprise, surprise - got it home and discovered they had not loaded the right model - instead, a top cable, taller model. First thought was to load it up - heavy - and take it back and provide appropriate feedback. We had a "wait a minute" moment and discovered the lift as designed was about 6 inches too tall. The top fixture which mounts some of the pulleys is bolted to the top of the uprights. Why not just drill new holes in the uprights 6 inches lower and adjust the cable length with shims. Fortunately we did not need to shorten the uprights. Took some time to drill the holes as the steel was some tough stuff. Worked out great and we got a lift custom fit to our garage - just by chance of course. 

And we quickly learned - there is no substitute for a lift - especially when one is getting a tad older and less flexible.

Question for anyone with a Bendpak GP7 lift. I'm thinking to buy one for my new garage

The brochure shows 110" between columns. I'm thinking that this is the effective drive thru width if the arms are lifted (89.5" drive thru width is with arms lowered?).

I have a Trailex 8045 that I'd like to store over winter. The trailer is 102" wide and it looks like it would fit between the columns. Is the floor area clear to allow the trailer to pass through?

BTW - the prices quoted in the article make me weep when you look at current pricing.........

codrus said:

I think it's worth mentioning that installing rolling bridge jacks on a 4-post lift mitigates a lot (although not all) of the drawbacks relative to a 2-post lift.  It does increase the cost by even more, but comes with many of the other 4-post advantages, such as narrower width and lack of floor anchor requirements.

 

Old thread, but I'm supremely interested in this - I was browsing questionable lift decisions on alibaba ...

https://www.alibaba.com/product-detail/High-Quality-Alignment-use-Four-Post_1600700133844.html?spm=a2700.galleryofferlist.0.0.4025599fzKdH23

https://www.alibaba.com/product-detail/Low-ceiling-Best-4-post-car_60873070480.html?spm=a2700.galleryofferlist_catalog.normal_offer.d_title.368196f7oXFmLE

glyn ellis said:

Question for anyone with a Bendpak GP7 lift. I'm thinking to buy one for my new garage

The brochure shows 110" between columns. I'm thinking that this is the effective drive thru width if the arms are lifted (89.5" drive thru width is with arms lowered?).

I have a Trailex 8045 that I'd like to store over winter. The trailer is 102" wide and it looks like it would fit between the columns. Is the floor area clear to allow the trailer to pass through?

 

BTW - the prices quoted in the article make me weep when you look at current pricing.........

With the arms up, the only thing blocking drive thru is the columns and their mounting plates/bolts, but I drive over them without issue. I've had trailers between my lift with the arms raised. 

Bit depends on your vehicle's proclivity for running over the mounting bolts. 

I saw the earlier comments on the 4 post with a bridge jack. I have to say after a few years of using mine I'm underwhelmed. Maybe with a longitudinal setup it's better but transverse FWD it's a pain to pull transmissions and getting an engine hoist positioned with the ramps up is a bit tricky as well. Just bought a 2 post and will decide if I keep the 4 after I work with it some.

Paul_VR6 (Forum Supporter) said:

Bit depends on your vehicle's proclivity for running over the mounting bolts. 

I saw the earlier comments on the 4 post with a bridge jack. I have to say after a few years of using mine I'm underwhelmed. Maybe with a longitudinal setup it's better but transverse FWD it's a pain to pull transmissions and getting an engine hoist positioned with the ramps up is a bit tricky as well. Just bought a 2 post and will decide if I keep the 4 after I work with it some.

I'd like to hear more about your experience. I have a small-ish 2 car with low ceilings - so I'd been considering the low two post, but I'm not sure my concrete is OK for it which brings a whole extra layer of annoying. With a 4 post it does seem like the center access will be rather annoying, but the side access with the two post seems worse. 

I currently have a nice titan scissor lift that I adore, but obviously not the best for working on the center sections and you can't even think about dropping the engine....

The under hoist stands are also an important safety feature that is often overlooked. 
 

They won't hold up the car, but they WILL keep the whole thing from rocking back and forth while you are torquing on one end of the car. Could prevent something catastrophic when there is 4000 lbs of vehicle in the air over your head. 
 

Once I had them, it was an easy habit to stick them under each end of the car while I was working under it. 

Yeah, dropping subframes (which is pretty much what you need for a transverse engine transmission swap) is the big thing that a 4-post/bridge jack combo can't do.

Keith Tanner said:

My 10k Bendpak two-post calls for 4".

I know this is an old post, but I'd like to clarify this a bit.

Benpak's specs say that a 4" reinforced 3500 psi slab is acceptable. That's a higher spec than most residential concrete slabs. 
 

But if you read into the details more closely, they also call for 4 1/2" of embedment for the anchors. In other words, 4" isn't enough. 
 

Residential slabs are often a NOMINAL 4". Just like a 2x4, that's not 4", that's 3 1/2".  And minor fluctuations in the grade under the slab can mean the thickness can vary. 
 

The difference between 4 1/2" required for embedment and 3 1/2" likely actual thickness is 22% less concrete.
 

My head is worth more than that to me.  I'd never do a 2 post lift in less than 5" of reinforced 3500 psi concrete. 
 

(I install about 50 lifts per year)

I'm pouring the slab in my new residential shop this week.  It will be 6" thick under the locations where a 2 post lift may sit in the future. 

Tom Suddard said:

glyn ellis said:

Question for anyone with a Bendpak GP7 lift. I'm thinking to buy one for my new garage

The brochure shows 110" between columns. I'm thinking that this is the effective drive thru width if the arms are lifted (89.5" drive thru width is with arms lowered?).

I have a Trailex 8045 that I'd like to store over winter. The trailer is 102" wide and it looks like it would fit between the columns. Is the floor area clear to allow the trailer to pass through?

 

BTW - the prices quoted in the article make me weep when you look at current pricing.........

With the arms up, the only thing blocking drive thru is the columns and their mounting plates/bolts, but I drive over them without issue. I've had trailers between my lift with the arms raised. 

Tom

Any chance that you could post a photo of the bottom of the column that would show the mounting  bolts and plates??

codrus (Forum Supporter) said:

Yeah, dropping subframes (which is pretty much what you need for a transverse engine transmission swap) is the big thing that a 4-post/bridge jack combo can't do.

 

For better or worse I don't drop the subframe I can get the transmission out by just removing the axle cup and some well practiced rotation. It's just my body needs to be *exactly* where the ramp is to do it. I tried different positions and at least on my car there's no good spot. 

Good call on the anchors, I'll check my manual again. Luckily I have light cars (<2k lbs) so not stressing things much at all.

In reply to accordionfolder :

Does the first one come with two bridge jacks? They seem impossibly cheap but man, if that's legit I want it badly

In reply to AMiataCalledSteve :

I've just been casually browsing, I think you have to contact the manufacturer to get the actual specs/final costs? I've read a few reviews saying the ones you get on Amazon are just rebadged versions of the alibaba ones - I haven't done a lot of research though. Just goofing.

SV reX said: My head is worth more than that to me.  I'd never do a 2 post lift in less than 5" of reinforced 3500 psi concrete.  (I install about 50 lifts per year)

You'll be excited to know, that my 4" slab has 2" foam under it except for a 4'x4' section under each post, making the total concrete 6". Except my excavator's sense of "level" for the slab would have worked on a much smaller planet, so I had to order an extra 2" of concrete, so it's likely upwards of 8" of concrete under each post.  Whee!

And golly, concrete is expensive.

In reply to SkinnyG (Forum Supporter) :

Good for you! Concrete is cheaper than a crushed skull. 
 

(I always do 8" when I am cutting new pads into an existing floor)

I've had a Bendpak 4 post lift with bridge jacks in my garage for several years.  For storage, it's clearly a winner over a 2 post lift.  For any work that requires you have to have the vehicle under it's own weight, like torqueing suspension bolts or hanging an exhaust, it's a winner.  With the bridge jacks, wheels off work like suspension or brake work is the same as a 2 post.  Where it fails is really heavy work like pulling engine/transmissions.  So if you're going to be doing that quite a bit, a 2 post is the way to go for sure.

Another thing to think of is a 4 post doesn't require the same concrete requirements as a two post and oddly enough, doesn't take up as much space in your garage as a 2 post.

Overall I'm happy with my choice but in a perfect world I'd have both a 2 post and a 4 post lift.  Since my garage only lets me have one, and I store a car up on the lift basically all winter, the 4 post is the one for me.