I was test driving a 2009 Titan AWD LE with about 130,000km (70,000miles). Drove OK in 2WD mode, but when I switched to 4WD high, it became noisy, a lot of vibration coming from front end, can feel it in steering wheel. It was noticeably binding in turns, and felt like I have 3000lb trailed attached (power was not there, felt restricted). Switched back to 2WD and it felt quiet and lively again. Does not feel normal to me - I suspect some issue with front diff or transfer case. Please reply with your experiences and comments. Thank you

Based on what I know about 4wd from other vehicles I've driven. Basically every thing under the sun but a titan. So no first hand experience... That is completely normal. When in 4wd your tranfercase locks together the front and rear differentials. As you go around a turn they spin at different speeds. All that difference scubs out through the tires which if not on slick surface goes into the components like shocks transmission engine mounts suspension as a whole. Its bad stuff really crack open the owners manual. It might mention not to activate on dry concrete.

That said they are all a bit different. AWD for example is commonly confused with 4wd which is NOT the same at all. The transfer case is a slipping" coupling in that situation.

All that said there is no telling AWD 4WD they are all different between manufactures. Id maybe drive a similar model vehicle to rule out.

The Titan does not come in AWD. If you were not driving in conditions where 4WD is needed and you attempt to take a turn, your front end will bind causing damage.

Current Titan owner here. Did you take it to an AutoZone or O'Reilly's to get a diagnostic scan? Could you tell whether or not the front tires were spinning while in 4wd?

The Titan front diffs are really strong, until you try to reverse in 4wd under load. For some reason that puts a lot of stress on the diffs and can cause them to blow. I'd bring it to the dealer's attention and see if you can't work the repair into the purchase if you're really interested in the truck. I can tell you even for an '09, 130k is not a lot of miles on these trucks. Several owners on titantalk.com and clubtitan.com have 300-400k on their 04's so I can assure you they're good trucks.

If you're still looking at the truck, go to Titantalk.com and search "4wd vibration". I found a thread but I'm apparently not allowed to post URLs here... If it doesn't answer your question continue to look around - lots of knowledgeable guys on the forum.