You should always consider getting a second opinion before letting a shop talk you into add on work.  Not saying your truck didn't need the additional repairs but having been in the industry for 20+ years, I do know that there are added incentives for the employees/technicians to find something wrong while it's in the shop.  A Lincoln/Mercury dealer I worked for back in the 90's would give us 10-20% commission on any add on sales.  When I opened my shop I told all of the employees we were to "only repair the items on the customer's repair ticket."  We would make note of any maintenance or safety issues on the invoice and the customer had the option of repairing them at a later date or not at all. 

Here's an example:

I have a 1997 Mercury Villager with 138,000 miles on it, I no longer have access to a shop or certain tools to make repairs (ie:alignment rack, tire machine, balancer).  I had a new set of Michelin tires installed at the local Discount Tire Store and they gave me a coupon for a free alignment check (at another location..Discount didn't do alignment checks).  I figured what the heck it was free, so I took the van to the shop and wouldn't you know it, the whole front end was about to fall out from under the van.  Yes, they even took me into the shop and showed me all of the worn parts while my vehicle was still on the rack.  Needless to say, they wouldn't give me the free alignment because my van's front end was going come apart at anytime if I didn't hand over $800 + dollars to these crooks.  I have done all of the routine maintenance since we purchased the van and I was fully aware of the condition of the front end before I took it to this shop but I figured it wouldn't hurt to check the alignment since it had never been done(and still hasn't).  I always check the front end when rotating tires or doing a front brake job and I watch the tires closely because they will let you know if an alignment is needed.  22,000 miles later my front end is still intact and my Michelin tires have very little tread wear, I think I'll get 80,000 on them, just like the last set of Michelins.