Author Topic: 2-Post vs 4-Post thoughts.  (Read 2887 times)

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McRat

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2-Post vs 4-Post thoughts.
« on: January 09, 2010, 04:04:36 PM »
some thoughts I posted on a diesel board concerning lift choices...

Quote from: Poltergeist;313265
Pat has a 4 post lift that has wheels on it. So even with a truck on it he can move it around. Hopefully he'll jump in here with info.

It was good in theory, and like many of my theories, didn't work in practice.

It is a Bendpak 4-post 9000lb with dolly wheels.  With 6400lb on it, it will not roll on the wheels, and struggles to lift 7000lb.

Since a lot of what I do requires lifting the tires off the ground, it is a poor choice.  They do make $$$ trolley jacks ($1200 ea?) to lift the frame, but they are too tall in the down position for working on lowered vehicles (5" required) and too expensive.

When you want to remove an engine, the cherry picker won't roll into the front without lifting the truck 6" which makes it harder to work on.

My suggestion to anyone serious about working on Duramaxes and smaller vehicles is a high-quality two post with at least 10,000lb AMERICAN rating.  My old two post was 11,000lb Chinese rating, which was truly dangerous with 7,000lb on it.

Mike L installed some very good units that I had the pleasure to work with.  Very sturdy, contact Mike L for the model #.

Now some other thoughts:

The 4 post BP roller will actually allow you to move the lift if your needs require it.  This is a big plus.  We rolled the lift outside to pressure the underside of the truck.  For a light car, you could roll it.  It makes an excellent "storage lift" for putting 2 or 3 cars in the same bay.  It is the best for fluid changes, shocks, exhaust, alignment, etc.  It's only when you need to use a cherry picker or pull the tires that it's a PITA.  It can be worked around easy enough, but you can get more work done per hours with the two post.

The biggest problems with the two posts are stability, preloading the suspension, and getting in and out of the truck.  We have waxed frames that far inboard, so on a two post it can "creep" as you lift and lower, or do heavy work.  I actually dropped Casper once due to creep, which is why I sold the 2 post.  Weak models allow the truck to wobble, which can creep or cause other problems.

Preloading, is when you need the truck tires on the ground to do certain tasks like check suspension/alignment stuff.  2 posts suck at this. 

Getting in and out of the truck with a two post sucks since the beams block the doors.  So always buy the widest model you can find.  Some of the narrow models will require you to push the vehicle into the bay or climb through the window.  With a four post, you can even get in and start the truck when in the air.

There needs to be a new lift design, that shares the best of both worlds.  Six post anyone?

Offline 4-barrel Mike

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Re: 2-Post vs 4-Post thoughts.
« Reply #1 on: January 09, 2010, 06:18:25 PM »
I worked for many years in a hot rod shop that had a top of the line Stinger 4-poster.  We could put a 3/4-ton extended cab 4-wheel-drive on it, put the wheels under it and roll it back into the corner, out of the way.

Since we built/worked on very low vehicles, by choice we put the vehicle on the lift to remove/install  an engine as it made getting under the vehicle much easier.

Just another side of the coin.  (The Duramax always went to the Chevy store (often) to be worked on.)

Mike
Mike Kelly - PROUD owner of the V4F that powered the #1931 VGC to a 82.803 mph record in 2008!

Offline Bob Drury

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Re: 2-Post vs 4-Post thoughts.
« Reply #2 on: January 09, 2010, 06:29:40 PM »
  A few years ago I had a friends 46 Ford convertable on a two post lift.  The car had no engine or transmission and I was trying to straighten and box the frame rails as the chassis was a mess.
  As I tried to lever the rear end to get it straight, one leg unloaded, the car rotated, and fell as I was trying to get a tack weld.
  Miracously, the right front leg went up through the transmission hole in the floorboard, spearing the car before it hit the ground, or me, leaving the car dangling at a 45 degree with the right front about a foot off the ground, and the left rear bumper about eight feet in the air.  Getting it back on the ground wasn't any fun either.
  Resulting damage, right door glass, right door chrome, 1 pair of boxers, and two days of serious nightmares.
  The only way I will ever get near one again is if it has positive rotational locks on the four legs..........Bob
Bob Drury

McRat

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Re: 2-Post vs 4-Post thoughts.
« Reply #3 on: January 09, 2010, 07:47:30 PM »
What happened to me with my two post, was I lifted and lowered it about a dozen times while working on something.  Each time, the feet "creeped" a bit because it never lifts 100% equal on both sides.  One always moves first.  It eventually walked off one of the feet, and only did minor damage, but like above, wrecked a good pair of BVD's. 

The real solution was not to buy such a cheezy lift (American Lift Products aka Chinese Rift Producks) or not to use flat rubber feet on the shoes.  A U-channel foot would have stopped the creep. 

The Bendpak has a video of one guy moving the lift with a Chevelle on it.  No way in heck could two of us move it with Casper on it, since the wheel mounts were starting to bend over.