Front end clicking sound

[jakejm79]

I am trying to help the new wife out with her 'Dora' a 250K+ mile 1998 Explorer Sport that had had just about everything replaced.

Anyway on with the story; Clicking/clunking sound with vibration under moderate to hard acceleration in Auto mode and any level of acceleration in 4Hi. My first thought was front CV joint (the BJs, hubs and UJs have all been recently replaced). Since I assume under hard acceleration in auto mode some power is sent to the front driveline and obviously it is in 4Hi.

I am quite a competent DIYer, but the world of transfer cases and 4WD is new to me.

I know it is difficult to diagnose based on such little info, so I am happy to take a list of steps to follow and report back.

 

[jakejm79]

So I drove the car again today and after a little research I am thinking it might my a sticking viscous coupling in the transfer case.
Here is a video it can be heard at the 3, 11, 18 and 22 second mark.

http://www.youtube.com/watch?v=c-B7ErJh914

It is more of a clunking and accompanied by a jolting/jerking/vibration. Definitely sounds/feels like something is sticking in the front. Doesn't happen at low speed/acceleration hard turning so I think that rules out the CV joints/axles.

Again it is noticeable under hard acceleration 1/3+ of accelerator pedal depressed in auto mode and almost any acceleration under 4Hi.

Kind of feels like when you have a diff locked vehicle and you make a hard turn (tho it will do it in a straight line) and the outside wheel skips.

 

[djblackout]

I am having this same issue!!!

except no cel or lights on

 

[jakejm79]

The lights are ABS and airbag which are unrelated. The bushings for the transmission mount are pretty beat, gonna change those and report back.