Bent Axle?

Hey guys, I just wanted to see what your take on all this is...I bought an 04' Titan CC 4X4 with 56K on it so I have been going though it step by step and getting it serviced.

I actually found that the left rear axle was leaking so I had that fixed (I know this is an isssue thanks to this web site). I then noticed that the parking brake had a lot of slop in it so I had them look at it while servicing the axle and sure enough it needed new parking brake shoes--no problem right... Well, I got a call yesterday while they were putting the shoes on and they couldn't complete the right side because the axle was too bent to put the shoes on. So I thought fine, the axle is bent and I need to pony up and just shell out the $350 for the parking brake and now an additional $480 for the right axle replacment (the axle had to be placed on order so it hasn't been replaced yet).

However, later that night, after looking at the service records for this truck (the lady I bought it from kept ALL the Nissan service records) it seems that a "pulsation/vibration" problem is documented at almost every service visit to them. Specifically, at 7K, 14K, 24K, 33K and 55K internvals with each of these service visits resulting in a brake and/or rotor job for front or back.

So, my interpretation of this is that the vibration all along was being caused or exacerbated by a right bent rear axle that has never been found? Is this a reasonable assumption or do I just need to quit whining and pony up and pay for the axle? I have searched this web-site and bent axles don't seem to be an issue really. So far the service/warranty writer doesn't really seem excited to say that it is covered under warranty even though the vibration issue is well documented. I have good rapport with her but this almost seems like a no-brainer when reviewing the service records. What do you think?

PS I love this Titan as it is hands down the best driving truck that I have every had but these axle problems have kind of caught me off guard.