Trailer mounted car lift? It sounds pretty brilliant to me. I think I'm going to have to build one.

I have a MaxJack lift. It's very handy. Unfortunately, the concrete where I had it mounted developed a crack. My plan was to replace the concrete but I think I have a better idea. Namely this. 

Building it should be a breeze. It will be portable and probably safer than bolting it down to the concrete. 

Looks like 30'-40' of 4" box, a sheet of diamond plate, and some welding should do the trick. I've got a trailer frame I can cut up for the tongue, axle, and such. I might need to wait for some cooler weather to get started but this is probably going to happen. 

Apparently there was one of these at the FIRM today, or there's going to be on there this weekend doing demos or something like that. I'll ping them and see if I can get any more info.

My shop is a little weirdly-shaped, so maybe I'm thinking about a use case that doesn't exist anywhere else, but would it make sense to build it such that it could be oriented 90 degrees?  If I wanted to use that inside my shop, for example, there's no way that I would be able to drop a trailer like that in such a way that you would be able to get between the posts from the garage door.  I'd have to back it in, drop the trailer, and then find some way to turn it 90 degrees.

Maybe you'd never want to use it in an indoor area that was constrained like that, but that was the only thought I had.

In reply to wae :

If you turn the lift 90 degrees on the trailer, it's going to be a wide load. My two-poster is 11' wide. You might also have difficulty dealing with getting the axles out of the way when you drop the lift to the ground, and the pull bar (I don't know the term) might have to be removed.

Better option would be some sort of wheel on the nose so you can disconnect from the vehicle and rotate the trailer 90 degrees.

In reply to wae :

I thought about that as well. A rolling trailer jack should solve that problem. With a castor on the nose you should be able to roll it in a shop, turn it 90 degrees, and use it. 

I just wish my shop had more than 8' ceilings. 

Edit: Or what Keith said. 

I think you could use removable pins for the tongue and the axle frame and remove those as well. 

Another thought is rolling trailer jacks on all 4 corners. Lift the deck, remove the tongue and axle, roll the lift into the shop, and lower it to the ground. 

Probably fine for a me-otter or some other sushi barge, but I wouldnt want to put an F250 on it without doing some serious maths.  Looks tippy.

After seeing one of these at a racetrack I wanted one. There's no way I could justify one, but they are so cool! You'd be the king of the paddock

93gsxturbo wrote: "...sushi barge..."

And this is now my phrase of the week, maybe the year!

In reply to 93gsxturbo :

The trailer's draw bar has a hydraulic cylinder and the axle has a cylinder making it the equivalent of a booster axle on a ready mix truck. Lift the draw bar and axle and the frame rests on the ground. Have some leveling feet on the frame and it's resting level. Carry a couple of 250 gallon water bags off of  Amazon and you can have 4000 pounds of counterweight.

I don't need to buy one but if my local equipment rental place (Bobcats, Construction equipment, etc) could have one I could rent for a long weekend, that could be really handy when the project dictates it. 

Would be best if it all was weather resistant so I could use it outside, temporarily.  

I would expect it would have to be weather resistant, given the fact that trailers tend to be outdoor use. It's a really cool concept.

Tom needs to build one and tow it behind/power it by his Lightning, for total off-the-grid operation.

In reply to John Welsh :

They will rent a pretty large forklift. I'm not saying it's a great way to lift a car for a weekend but it also wasn't the worst. 

There's usually one of these following the drag and drive events around.

Rons said:

In reply to 93gsxturbo :

The trailer's draw bar has a hydraulic cylinder and the axle has a cylinder making it the equivalent of a booster axle on a ready mix truck. Lift the draw bar and axle and the frame rests on the ground. Have some leveling feet on the frame and it's resting level. Carry a couple of 250 gallon water bags off of  Amazon and you can have 4000 pounds of counterweight.

Think about this for a second, Ron.  

Max legal width is 8.5 feet without an oversize load permit.  So per side you have 51" from centerline to the edge of the plate.  Lets figure this is a symmetrical lift and you have the posts about in the centerline of the wheelbase.  

With a little car like the aformentioned Miata, the wheel centerlines sit inbound of the plate by about 5" per side.  Probably OK, all the mass being lifted is contained within the footprint of the plate.  Pretty tough to tip over, even misloaded or with the engine pulled out.  

A Mustang has a 107" wheelbase.  So your wheel centerlines are just on the outside of your 102" plate by 2.5"   Should also be fine for most stuff, but could get tippy if you load it biased one direction and then remove a major weighted component on the "short" side.

Now..Take an F250.  176" wheelbase.  Figure the approximately 30" long engine is going to sit around centerline of the wheelbase, and you have the entire mass of the engine sitting out past the width of the plate.  Symmetrically loaded, each wheel centerline is 37" past the edge of the plate.  Just some rough ballpark math and the start of the mass of the engine is 12-15" past the outside edge of the plate.

You can go under it.  I won't.

In reply to 93gsxturbo :

That's an easily solved problem. A set of slide-out outriggers with some type of jack at the end and you can make the platform as wide as you want. 

In reply to 93gsxturbo :

The lift arms are considerably shorter then the platform width. Due to this, you can't create the right forces to tip the platform, but you can tip the vehicle on the lift arms much like you can on any two post lift.  The exception to this would be if you tied the vehicle to the lift arms, then you could in theory tip the whole assembly with enough overhanging load. 

Note: This is before morning coffee so I am not betting the farm on it. 

The more I look at it the worse and better it gets at the same time. 

If the lift arms do not extend past the edge of the baseplate and you do not use up limit straps to hold the vehicle down it is Physically impossible to tip the whole thing over.  

That does not mean you couldn't knock the truck off the lift just like you could on a normal lift.  

Assuming you load the lift with the truck CG nearly in the middle like you should with the arms as wide as they can get the heavier vehicle has the potential to be more stable on the lift

Let's say the lift trailer is 2500lbs and it's CG is centered on the baseplate (51" from the edge).  A F350 CCLB DRW is 8500lbs and ~60/40 F/R.  It's 266" long.  Assuming it's CG is within say 24" of the center of the lift (51-24=27" from edge), and dumb mechanic has stepped on open tailgate to climb into the truck held up by the lift (60% of 266"+~15" for tailgate from truck CG, which is 27" inboard of the baseplate so mechanic is 159+15-27=132" from the edge of the plate).   How heavy would dumb mechanic (DM) have to be to cause mayhem assuming the truck is welded to the lift?  We sum the moments about the edge of the baseplate.

51"×2500+27"x8500-132"xDM=0

DM=2704lbs to get the whole thing to tip.  

Even ignoring the weight of the lift trailer it is still a large amount of weight you need to tip the whole thing, it just becomes equal to what it takes to tip the truck off. 

Assuming the lift arms are at 8.5' wide the truck will tip off at DM>1738lbs.

Repeating for a Miata at 154" OAL, same CG location of 27" from baseplate edge.  

51"x2500+27"x2500-26"xDM=0

DM=7500lbs to tip it. 

Practically it would likely be impossible to get a Miata lift arms at the edge of the baseplate and more typically they would be ~48" apart which would mean a Miata could likely be tipped off the lift with a relatively low DM weight.  Miata is 50/50 so CG is in the middle of the lift arms 24" from the pads, but our lever arm is 77-24=53" to the bumper.  If you have the CG offset much at all the weights required to tip the Miata start to get fairly small, around 1100lbs with a centered CG.  If the CG is offset  20" the load can be as low as 200lbs to tip the car off.  200

In fact the smaller the car the more critical weight balance and CG location on a lift gets.  

Looking up some dimensions for typical lift arms it looks like you could get close to having the lift arms at the edge of the pad.  So if you loaded a car with it's CG exactly on one pad, fully extended, it still wouldn't tip because the cg of the lift is inside the base and wouldnt tip, but the car would fall off real easy.  

TLDR assuming the baseplate is well designed and attached to the columns with the same fastener strength as a concrete mounted lift I would be no more hesitant to get under that with a F250 on it than a normal floor mounted 2 post.   It is physically impossible for it to tip over unless the baseplate is to weak for the application.

Outriggers is a very good idea because you'll want to make sure it's pretty damn level anyway, a little bit off with tons of weight gets pretty exaggerated.

for all the race, rallycross, and stage rallies i've done, I can't think of a single time i was like "if only I had a lift here I could...." IDK, maybe you guys do more crazy stuff than me lol. Just the thought of having to tow TWO trailers around to races 5, 10, 15 hours away hurts my wallet even more than just towing the racecars lol....

now, if you could design a trailer with a lift AND that could carry the car as well......but I guess that's just a stacker trailer at that point. 

irish44j (Forum Supporter) said:

for all the race, rallycross, and stage rallies i've done, I can't think of a single time i was like "if only I had a lift here I could...." IDK, maybe you guys do more crazy stuff than me lol. Just the thought of having to tow TWO trailers around to races 5, 10, 15 hours away hurts my wallet even more than just towing the racecars lol....

now, if you could design a trailer with a lift AND that could carry the car as well......but I guess that's just a stacker trailer at that point. 

Maybe I'm reading this wrong, but I see this as more of a 'move it around the property' or 'move it around locally' thing, not something that would be brought to events.

In reply to ProDarwin :

Correct. My lift is installed in front of my shop. I don't like leaving it out because it makes the backyard look junky. That means unbolting it, piling it in a corner until the next time it's used. That limits me to the MaxJax. 

Trailer mounted, I could use full-height columns. It would also be portable. I could use it in my father's shop as well as haul it to the office to do maintenance on the work fleet. 

I'm already shopping for materials. Expect a build thread once the weather cools off some. 

irish44j (Forum Supporter) said:

for all the race, rallycross, and stage rallies i've done, I can't think of a single time i was like "if only I had a lift here I could...." IDK, maybe you guys do more crazy stuff than me lol. Just the thought of having to tow TWO trailers around to races 5, 10, 15 hours away hurts my wallet even more than just towing the racecars lol....

We've swapped a few transmissions at races and I would have much rather been under a lift than on my back with jackstands. Also, we bring like 5-10 people so one person could tow the car and another the lift. If you're a one-tow-pig operation then this makes no sense for you.

buzzboy said:

irish44j (Forum Supporter) said:

for all the race, rallycross, and stage rallies i've done, I can't think of a single time i was like "if only I had a lift here I could...." IDK, maybe you guys do more crazy stuff than me lol. Just the thought of having to tow TWO trailers around to races 5, 10, 15 hours away hurts my wallet even more than just towing the racecars lol....

We've swapped a few transmissions at races and I would have much rather been under a lift than on my back with jackstands. Also, we bring like 5-10 people so one person could tow the car and another the lift. If you're a one-tow-pig operation then this makes no sense for you.

We have other people, but as the team principle, I'd still be paying for the gas for multiple rigs. NEFR last year was $700 in gas alone, and that was just towing 1 trailer! Rally doesn't get to split it up like 4-person enduro teams haha. 

Point taken on the move it around the property though.