Isuzu Repair: steering pump and gear box 1996 Rodeo, isuzu rodeo, wheel bearings

Question
QUESTION: Strange question. When in reverse, as I pull out of the driveway and turn left as I'm doing this, my steering wheel seems to pull hard and kind of jiggles and it almost feels like the tires are slipping on a smooth surface. It's hard to describe. Doesn't happen going forward. Mechanic tells me I need to replace steering pump and gear box.  Does this sound right?

ANSWER: Does it vibrate at all going down the road? What size engine and transmission?

---------- FOLLOW-UP ----------

QUESTION: No it doesn't vibrate on the road.  I had a wheel alignment not too long ago. I tried last night turning to the right as I'm backing up as well and it does the same thing. It's a 1996 Isuzu Rodeo 3.2 V6, 2WD.
If this is what I need to have done can it be done in stages or do both things need to be done at the same time. Thank you so much for your initial quick response.  I look forward to your next answer.  This is a big help. Thanks again!

Answer
Well the problem could be anything from mis-adjusted wheel bearings to worn power steering pumo/hoses and or steering gear. Im just being honest with you it is hard to sya for sure though because I actually cant see it for myself Debbie. I hope this helped though>