After mechanic replaced rack and pinion, steering 2nd time steering has more play than before and he suggested replacing the steering column to correct problem. Should I get 2nd opinion?

The shaft itself is not the issue. There are bearing and gears in the column and the rack and pinion.

Sounds like the reel cord under the steering wheel, on the steering column broke. Without the rack and pinion engaged to the steering column, the steering wheel spins freely if spun intentionally or accidentally. If so, the reel cord containing wiring and circuits, reel cord is damaged by such action.

If your steering wheels turns all the way but your wheels don't:
This would have to be either a broken rack and pinion(steering gear) or the shaft between the rack and pinion and the steering wheel would have to be broken. This would need to be visually inspected to be sure which is the problem.

I would have to guess that your steering wheel is no longer connected to the rack (as opposed to something in the rack breaking). My best guess is that your steering column shaft snapped.

They can be replaced, and the necessary parts are sold, but it's not the easiest thing in the world to replace.

stick your head down under the dash on the driver's side where the brake and gas pedals are, and look up at the steering shaft (can't miss it). Now turn the steering wheel. Does that shaft turn?

Are you referring to the rack and pinion steering assembly? If so, repairing or rebuilding this unit requires very specialized tools. Even auto repair shops do not fix these. We simply remove the defective unit and replace it with another good complete unit.
If you are asking how to replace this unit, that also requires special tools to remove the tie rods. You must also be very careful and know what you are doing or you can ruin the clock spring for the driver's side airbag. The shaft for the steering column is "phased" to the shaft on the pinion gear. You must be sure to keep the steering column and the new rack & pinion assembly in phase or you can do more damage to your truck. You will also need to take the truck to a shop for a front end alignment after you are done. If you think that you have the skills to handle this job, I would suggest you watch the videos I've linked. FYI, it will take a skilled mechanic with all the proper tools over 4 hours to do this job.
Rack Pinion power Steering Rack and pinion Replacement ford explorer part 1

A bad seal in the rack and pinion would have caused low pressure from fluid by-passing the seal. This also would have caused noticeably increased effort to steer the vehicle. Excessively high pressure would indicate an issue between the power steering pump and the rack, and since the hoses have been replaced I would focus on the pump. PS, find a real mechanic, not a parts changer.

Go back to the 'mechanic' who installed the parts.

There are few help links showing exact accurate procedure to replace Rack and Pinion. Click the link below and follow the procedure:-----
Pinion Seal Replace on Dodge Dakota? http://howtobyme.blogspot.in/2012/04/pinion-seal-replace-on-dodge-dakota.html

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How to Replace a Rear Pinion Seal.
http://schematicsdiagram.blogspot.com/2011/07/how-to-replace-rear-pinion-seal.html
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How to replace Power steering rack and pinion gear on Chevy Silverado 2500 HD? http://technoanswers.blogspot.in/2012/02/how-to-replace-power-steering-rack-and.html

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How to replace Power Rack and Pinion Steering Gear on Acura Car Models? http://repairhelpcenter.blogspot.com/2011/11/how-to-replace-power-rack-and-pinion.html

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How to replace power rack and pinion steering gear on Toyota cruiser? http://repairhelpcenter.blogspot.in/2012/02/how-to-replace-power-rack-and-pinion.html

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How to replace Power Rack and Pinion Steering Gear on Acura Car Models? http://repairhelpcenter.blogspot.com/2011/11/how-to-replace-power-rack-and-pinion.html


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Front Drive Pinion Seal Removal on Ford Explorer? http://repairhelpcenter.blogspot.in/2012/03/front-drive-pinion-seal-removal-on-ford.html

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How to Replace Driveshaft, Pinion Flange & Seal?

http://repairhelpcenter.blogspot.in/2012/03/how-to-replace-driveshaft-pinion-flange.html

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How to Replace Power Rack & Pinion Steering Gear On 2007 Ford Taurus? http://repairhelpcenter.blogspot.in/2012/03/how-to-replace-power-rack-pinion.html


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How to Remove Power Rack & Pinion Steering Gear on Ford Windstar? http://repairhelpcenter.blogspot.in/2012/03/how-to-remove-power-rack-pinion.html

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Power Rack & Pinion Steering Gear replacing details for Buick Park Avenue and Pontiac Bonneville

http://repairhelpcenter.blogspot.in/2012/03/power-rack-pinion-steering-gear.html

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How to Replace Power Rack & Pinion Steering Gear on Mercedes Benz Truck? http://howtobyme.blogspot.in/2012/03/how-to-replace-power-rack-pinion.html


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How to replace Power Rack & Pinion Steering Gear on Toyota 4Runner? http://howtobyme.blogspot.in/2012/03/how-to-replace-power-rack-pinion_27.html

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Power Rack & Pinion Steering Gear Replacing on Toyota Land Cruiser & Sequoia? http://schematicsdiagram.blogspot.in/2012/03/power-rack-pinion-steering-gear.html

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Power Rack & Pinion Steering Gear Removal on Toyota RAV4? http://repairhelpcenter.blogspot.in/2012/03/power-rack-pinion-steering-gear-removal.html

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How to Replace Power Rack & Pinion Steering Gear on Toyota Sienna? http://technoanswers.blogspot.in/2012/03/how-to-replace-power-rack-pinion.html

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These details will help.
Thanks.

Hi Gunny, If your vehicle is fitted with rack and pinion steering also check the rack ends for play. The rack ends are the rods which the tie rod ends screw onto. The other end fits onto the rack of the rack and pinion. To work on those you will need to remove the rubber boots and loosen the locking washer, they can then be loosened with a wrench. If they are worn the play will be evident in the steering. When replacing them also replace the rubber boots. If the boots are worn and road grime and dust enters, you will see leakage from the rack and pinion in the near future. I always thought the Dakota was fitted with a steering box? Regards John

if the rack and pinion was not leaking or causing problems. then he may of made a wrong move! if the rack was fine before, and you just lost power steering. then it is most likely the power steering pump or the lines that go from rack to the pump. good-day ! if a rack goes bad, you will get a bad steering problem or just bad steering.

This clicking noise that you said does it do it when you turn? If so your problem lies in your CVJoints. Constant velocity joints are attached to the steering mechanism. Try an experiment first. Get the vehicle at about 15 mph and do a small donut (controlled) parking lot would be easier for this and safer. Then turn the opposite direction. If the clicking noise is on both directions then you might as well replace both inner and outer CV joints for the right and left side. It might be your rack and pinion as well. The joints fail first before your rack and pinion so check that first. You may want to see the fluid level on the rack and pinion to see if that was the problem. Check the cheapest thing first. Let me know Gabe.