What's this annoying sound?

[tomzapf]

My 2000 4wd Limited with 175k is making a ticking sound at around 30mph and gets louder as speed increases. It sounds like it's coming from the tranny area, my transmission/4wd is working fine. Here is a video of what it sounds like.

Noise from gear box - YouTube

 

[FancyPantsMcGee]

try putting the truck into 2nd gear and getting it up to 30+mph to see if it is gear dependent.
inspect your u-joints for excess play..
that's a tough one.

 

[CdaleR4000si]

Not sure, at first I was thinking u-joints also. Before I lubed mine, it made some pretty strange noises, sometimes it sounded like a rattle, other times it made a sound that I can only describe as a "wooshing, metallic" noise. I would say to get yourself a cheap digital recorder and attach some neodymium magnets to it, then stick it to the frame rail near the suspected source of the noise. Drive around for bit while recording and see what it sound like. Keep moving the recorder to different spots until you find the source.

 

[tomzapf]

Today on the way to work I put it in 2nd gear and kept it there till about 40-45 same noise so I don't think its the transmission. Also when I throw it in Neutral at 35 and up the noise continues until I slow down to about 20mph.

 

[tomzapf]

Just thought of something, also for a while when in Park I hear rattling from underneath, kind of like the catalitic converter shield or the unit is going bad. I'm wondering now if that could be my issue. I haven't gotten underneath the truck yet but I plan to tap a few things see what rattles. Anyone?

 

[fluffeh]

Definitely possible. That's a very common problem among these runners.