Hey all,

I have a 2001 4wd SR5 4Runner w/ Sonoran Steel System 7.1 lift and am trying to trace a strange noise in the drivetrain. Here is what I know:

This is a ticking/clicking noise that occurs under load when accelerating from a stop. It is speed-variable, and I hear it most clearly with the windows down and when accelerating up a grade, but it also occurs on flat ground ( basically when the drivetrain is under load).

It is most clearly heard at slow speeds, since as speed increases, so do engine, road, and wind noise. For example, I was driving around a local neighborhood looking at houses the other day (a lot of stops and starts) and could clearly hear the ticking sound bouncing off of other cars and houses as I accelerated.

Initially I thought it was a valve noise, but it does not occur in park/neutral and after fooling around today I discovered that it goes away when I'm in 4wd (center diff open). The truck shifts fine, and 4wd and center diff lock all work. I have a slight driveline vibration at 65-70 mph which I attribute to my rear driveshaft being out of balance due to being lengthened by the lift, but do not think this is related. I have replaced the fluids in the tranny, transfer, and F&R diffs in addition to greasing all my u-joints in the past year.

Any ideas what this might be?

 

Sounds like a u-joint. You should grease all your u-joints every oil change and after you go wheeling where their is a lot of mud, water or sand. Once a year greasing is not enough.

James