glennQNYC wrote

Thanks Mike. To me it seems better to have the suspension (and tires) unloaded. I find it difficult to even contemplate why keeping the suspension and tires under load is preferable.

Living and working in downtown Chicago I've seen a lot of cars sitting in these under ground garage with 3in of dust on them. All people do is put carpet down and let the car sit on that. Seems to help prevent dry rotting.

To me personally it makes no difference between loaded and unloaded. Just do what works best for you.

Mike

glennQNYC wrote

Help me understand this theory. How is this worse for the bushings than having the weight of the car on them?

I can't help you understand. My car still has most all of its original (12 year old) bushings. I leave my car on my lift for days at a time.

glennQNYC wrote

Thanks Mike. To me it seems better to have the suspension (and tires) unloaded. I find it difficult to even contemplate why keeping the suspension and tires under load is preferable.

Never ever leave your suspension unloaded!

A 2-post is a very good lift to work on your car, but its totally unsuitable for storing a car (1 or 2 weeks wont hurt, but months on end is a nono).

Within your suspension, there are loads of bushings (almost all of them on a stock car) that are fitted with pretension, or better said, no tension when the car sits at ride height.
When the car doesnt sit at ride height, those rubber bushings sit twisted under tension in their casing/control arm/shockabsorber. Over time they will tear.
Thats why in all workshop manuals is shown whether a bushing should be fitten with pretension (or snugged up with the wheels on the ground) or not.
Even with lowering a car, one should retension those bushings to the adjusted heights.

So my guess is that the 50% that say that suspension shouldnt stay extended for prolongued time are probably the 50% that have actually read a workshop manual in their life and have actual hands on experience working on cars

So imho its very simple, if you buy a lift to store cars, get a 4 post. If you buy a lift to work on cars, get a 2 post (although 4 posts are better to do very small jobs (a car is more easily put on a 4 post lift) or bodywork, so each has its place)
If you have the room....get both

As long as the weight is equally distributed, I have no problem servicing a heavier vehicle like LX470 or a lighter one like a Camry. Detailing a vehicle is so much easier and fun too

GuidoK wrote

Never ever leave your suspension unloaded!

A 2-post is a very good lift to work on your car, but its totally unsuitable for storing a car (1 or 2 weeks wont hurt, but months on end is a nono).

Within your suspension, there are loads of bushings (almost all of them on a stock car) that are fitted with pretension, or better said, no tension when the car sits at ride height.
When the car doesnt sit at ride height, those rubber bushings sit twisted under tension in their casing/control arm/shockabsorber. Over time they will tear.
Thats why in all workshop manuals is shown whether a bushing should be fitten with pretension (or snugged up with the wheels on the ground) or not.
Even with lowering a car, one should retension those bushings to the adjusted heights.

So my guess is that the 50% that say that suspension shouldnt stay extended for prolongued time are probably the 50% that have actually read a workshop manual in their life and have actual hands on experience working on cars

So imho its very simple, if you buy a lift to store cars, get a 4 post. If you buy a lift to work on cars, get a 2 post (although 4 posts are better to do very small jobs (a car is more easily put on a 4 post lift) or bodywork, so each has its place)
If you have the room....get both

LOL... BS meter pegged.

I have a revolution 2 post lift. Paid about $3,500 for it and to get it installed professionally in my shop. Works great for cleaning, suspension, maintenance, etc

Efthreeoh wrote

LOL... BS meter pegged.

What do you mean?

GuidoK wrote

What do you mean?

I mean that I've been working on cars for over 40 years. Before the internet, one had to buy a service manual either published by the manufacturer or an aftermarket publisher such as Bentley, Haynes, Chilton's, just to name three. I can't not recall any repair manual I've used making caution statements in the general information section regarding the length of time one can or should leave a car off its suspension.

Regarding 2-post and 4-post lifts, you stated that putting a car on a 4-post lift is easier and faster, and I simply disagree. My asymmetrical Rotary lift comes with a floor plate used to locate the car relative to the lift. I can have any of my automobiles lifted to full height in about a minute and a half for simple maintenance items, like an oil change.

Efthreeoh wrote

My asymmetrical Rotary lift comes with a floor plate used to locate the car relative to the lift. I can have any of my automobiles lifted to full height in about a minute and a half for simple maintenance items, like an oil change.

Please explain floor plate and how it helps jacking up the car relatively quicker?

4 post even if it's 220V, still is slower than the 2 post to go up and own. Lifting aluminum j, positioning them for taking the car off and then putting them back do take some time.

2 post, if you know the lifting points, may be few minutes quicker but then you have to bend over and position the arms before lifting the vehicle.

I can tell you this though, I have 5 car garage on the main floor and an another garage in the basement and I would rather do another driveway to the basement ($4000-$6000) than getting another 4 post ($3500-$4000).

quick wrote

Please explain floor plate and how it helps jacking up the car relatively quicker?

4 post even if it's 220V, still is slower than the 2 post to go up and own. Lifting aluminum j, positioning them for taking the car off and then putting them back do take some time.

2 post, if you know the lifting points, may be few minutes quicker but then you have to bend over and position the arms before lifting the vehicle.

I can tell you this though, I have 5 car garage on the main floor and an another garage in the basement and I would rather do another driveway to the basement ($4000-$6000) than getting another 4 post ($3500-$4000).

My lift is asymmetrical, which means the columns are turned about 30 deg. towards the rear of the vehicle. This places the center of gravity rear of the cross-centerline between the posts. The positioning plate is necessary to place the car in alignment with the shifted center of gravity, so for my lift, there are three (3) positions based on wheelbase length. 106" is the baseline, which places the left front wheel on the center of the plate, less that 106" places the left front wheel behind the plate; longer than 106" places the left front wheel ahead of the plate. The plate has a ridge on each end to feel as the tire bumps up to it or over it. You can see it in this pic.

Your lift is symmetrical, which doesn't require a locating plate as long as the vehicle is pretty much on the centerline (longitudinal) of the columns. I also didn't want to mention that most 4-post lifts are much slower to rise than a 2 post lift because the Bend Pack brand 4-posters are 45 seconds rise. Newer lifts from Bend Pack and Rotary have lift rise speeds of around 30 seconds now. My lift is 45 second, but it is a 2004 model.

Efthreeoh wrote

I mean that I've been working on cars for over 40 years. Before the internet, one had to buy a service manual either published by the manufacturer or an aftermarket publisher such as Bentley, Haynes, Chilton's, just to name three. I can't not recall any repair manual I've used making caution statements in the general information section regarding the length of time one can or should leave a car off its suspension.

Well, I cant claim that I've been repairing cars for 40 years, as I'm not that old, but I have since the mid 90's, so I guess thats 25 years.
Where did I say that repair manuals made caution statements about the lenght of time one can leave a car off its suspension?
I said that they show lots of time to fit a bushing under pretension/torqued with the wheels on the ground.
Ever wondered why?

Regarding 2-post and 4-post lifts, you stated that putting a car on a 4-post lift is easier and faster, and I simply disagree. My asymmetrical Rotary lift comes with a floor plate used to locate the car relative to the lift. I can have any of my automobiles lifted to full height in about a minute and a half for simple maintenance items, like an oil change.

Ok, we can disagree on that. But when did you ever see for example a MOT station where the inspection was done on 2 posts?
Exactly, the all use 4 posts.
Because its faster. Easier. You do it in 1,5 minutes. With a 4 post or scissor, you simply drive on. Thats it, and thats simply faster than your 1,5 minutes or how fast you think it is.

I also have an asymetric 2 post, and for getting it quick in the air it's just not as good/convenient. But a 2 post has lots of other advantages.

Mine is an asymmetrical as well and I just visualize the balance of the car while positioning it to make sure the cars don't tilt, does that make sense?

GuidoK wrote

Well, I cant claim that I've been repairing cars for 40 years, as I'm not that old, but I have since the mid 90's, so I guess thats 25 years.
Where did I say that repair manuals made caution statements about the lenght of time one can leave a car off its suspension?
I said that they show lots of time to fit a bushing under pretension/torqued with the wheels on the ground.
Ever wondered why?



Ok, we can disagree on that. But when did you ever see for example a MOT station where the inspection was done on 2 posts?
Exactly, the all use 4 posts.
Because its faster. Easier. You do it in 1,5 minutes. With a 4 post or scissor, you simply drive on. Thats it, and thats simply faster than your 1,5 minutes or how fast you think it is.

I also have an asymetric 2 post, and for getting it quick in the air it's just not as good/convenient. But a 2 post has lots of other advantages.

You said "So my guess is that the 50% that say that suspension shouldnt stay extended for prolongued time are probably the 50% that have actually read a workshop manual in their life and have actual hands on experience working on cars." I think that means people who have read a shop manual know it is bad to leave a car on a lift with the suspension hanging vs. people who haven't read a shop manual are the people who don't know better (and presumably damage their suspensions). I'd estimate that my E90 over its 12-year lifetime has spent probably around 10 weeks in total with its suspension hanging (a few stints were over 10 days each) and all but the thrust arm and front lower control arm bushings are original. So I just disagree with your statement based on my direct experience. I do not think it harms the suspension to leave it unloaded for long periods of time. I replaced my original front control arms at 336,000 miles in December of 2017. I still have the old original arms, I'll take a close up pic of the bushings today and show you there are no tears in the rubber isolators. In fact I tested the old arms against the new arms to see how bad the old bushing were vs. the new ones, and I could barely tell the difference.

Plus not all suspension bushings need to have the suspension loaded. Bushings that are located vertically wouldn't.

stephanporsche wrote

I have 10'6" ceilings and installed a Dannmar D7, with my Porsche and BMW the lift goes all the way up and I am easily able to work under the vehicles.

Wow man that is an awesome garage setup. I hope to afford a setup like this one day with a few 911’s to boot!

quick wrote

Mine is an asymmetrical as well and I just visualize the balance of the car while positioning it to make sure the cars don't tilt, does that make sense?

It's hard to tell by the pics of your 2-post; the columns do not look like they are rotated very far. Looking at it closer now, I do see the front lift arms are a different configuration than the rears (shorter). Challenger takes a different approach to its lift design that Rotary and uses over-sized columns (compared to the Rotary), so perhaps locating the center of gravity is not as critical vs. the Rotary design. My lift is 10,000 lbs capacity. I helped install mine, and it was quite complicated to layout the centerlines for the columns and locating plate. The installer knew what he was doing he didn't even reference the installation instructions because had had done so many.

I like your shop BTW.

Regarding your driveway comment, right now I have "storage" for 6 cars if I want. I built a 3-car carport and my shop can store 3 cars ( 2 - doubled-up on the lift if I want to damage the suspension of one ) and a motorcycle or two. If I need more storage I can build another carport if I need to, I have plenty of room.

Efthreeoh wrote

I'd estimate that my E90 over its 12-year lifetime has spent probably around 10 weeks in total with its suspension hanging (a few stints were over 10 days each) and all but the thrust arm and front lower control arm bushings are original. So I just disagree with your statement based on my direct experience.

Lol, we're talking here about storing a car on a 2 post.
And you talk about 10 weeks in total on a 12 year old car?
12 years is 624 weeks. In that scope how is 10 weeks prolonghed time?
and stints over 10 days? We're talking about completely different time spans.
I was talking about months on end and said a few weeks is ok.
Do you think a 10 day stint falls in the catagory months on end or a few weeks?

With storing a car on a 2 post, I mean that it sits 10 months/year or so on a 2 post, the vast majority of the time, using it as an extra indoor parking space like the TS intends. Like the time a garage queen sits in the garage.
So that is say over 50 times as long or so as the time you're talking about.
You still think thats ok for the suspension of a car?

Efthreeoh wrote

Plus not all suspension bushings need to have the suspension loaded. Bushings that are located vertically wouldn't.

Sure. But how many vertically located suspension bushings does your bmw have compared to horizontally located bushings?
It's certainly not the majority Or do you think otherwise? Shall we do a count on your z4?

And does it matter? If 1 busing fails because of improper storage, I'd say thats already 1 too many dont you think?

How about buying the tall stands to put underneath the tires to support them, problem solved? They are really not that expensive, may be $100 give and take

GuidoK wrote

Lol, we're talking here about storing a car on a 2 post.
And you talk about 10 weeks in total on a 12 year old car?
12 years is 624 weeks. In that scope how is 10 weeks prolonghed time?
and stints over 10 days? We're talking about completely different time spans.
I was talking about months on end and said a few weeks is ok.
Do you think a 10 day stint falls in the catagory months on end or a few weeks?

With storing a car on a 2 post, I mean that it sits 10 months/year or so on a 2 post, the vast majority of the time, using it as an extra indoor parking space like the TS intends. Like the time a garage queen sits in the garage.
So that is say over 50 times as long or so as the time you're talking about.
You still think thats ok for the suspension of a car?



Sure. But how many vertically located suspension bushings does your bmw have compared to horizontally located bushings?
It's certainly not the majority Or do you think otherwise? Shall we do a count on your z4?

And does it matter? If 1 busing fails because of improper storage, I'd say thats already 1 too many dont you think?

This is the point of the argument. If it stresses the bushings to leave them torqued with the suspension unloaded, then time is additive on the bushing; it's not like they magically recover once reloaded. Meaning, leaving the suspension unloaded is within the arc of movement of the bushings are designed for.

I'm not going to argue the point of storing garage queens; I don't see the point of having one. Speaking of the Z4, it needs brakes, which I'm heading out to replace. I'll have to work quick to prevent bushing damage . I'll count up the verticals too...

quick wrote

How about buying the tall stands to put underneath the tires to support them, problem solved? They are really not that expensive, may be $100 give and take

That's what I said a while back....

Savageenterprise wrote

stephanporsche wrote

I have 10'6" ceilings and installed a Dannmar D7, with my Porsche and BMW the lift goes all the way up and I am easily able to work under the vehicles.

Wow man that is an awesome garage setup. I hope to afford a setup like this one day with a few 911’s to boot!

Thanks. I would say 10'6" is the lowest you could have to work on a Porsche or BMW fully lifted. I'm sure you will get a 911, 996 & 997 are very affordable and VERY EASY to work on.

Efthreeoh wrote

I'll have to work quick to prevent bushing damage . I'll count up the verticals too...

Yes, you'll have to work quickly if you cant fit new brakes in a few weeks.
I'm sure you'll manage

quick wrote

How about buying the tall stands to put underneath the tires to support them, problem solved? They are really not that expensive, may be $100 give and take

If you think you can support all 4 corners to suspension ride height with those stands without the car rolling of the lift or create another unsafe situation..
Go ahead:D

How you're going to fit another car under there with the tripods taking up that space I'd really like to see:D

If you want to use a 2 post for storage reasons, storing another car underneath, imho the only option is to get one with wheel adapters.
So something like this:


Although I think that any liftpost manufacturer will say when asked that storing a car on their post isn't its inteded use, except when buying a storage lift (these also exist, are usually 4 post and more compact and less high)