Clunking/Clicking Sound when FWD Engaged

[cabraljf]

I have a stock 1991 Ford Explorer Sport. The problems I am having is a clunking/ticking sound only when the FWD is engaged. The clunking gets faster as I drive faster. At first I thought it might have been the hubs. After replacing both the sound is still there. The sound seems to be coming from the front of the vehicle. The only other thing I can think of is maybe the motor that engages the transfer case isn’t locking fully. Anyone have any suggestions???

 

[ExploringNC]

Not sure how much you know about 4 wheel drives so this may be a dumb question but are you driving on pavement? If you have it in 4WD then the ground surface must be loose or the driveline will bindup.

 

[pwrranger88]

sounds like bad universal joints. did you replace the hubs with the electronic hubs?

 

[cabraljf]

I can hear the sound if I drive on dirt or pavement. Hubs lock automaticaly. I have a push button FWD.

 

[pwrranger88]

I can hear the sound if I drive on dirt or pavement. Hubs lock automaticaly. I have a push button FWD.

did you grease the new hubs before you put them on? most people put to much grease on the hubs which make them not engage
here is a link that tells you how to clean the hubs if thre is to much grease in them http://www.therangerstation.com/tech_library/HubDiagnosis.html

 

[cabraljf]

Yes, both hubs were degresed and then packed with new grease. I am an engineer at NSK (my plant that makes wheel hub bearings for Honda, Toyota, Chrysler and VW). I am not a certified mechanic but I think that the bearings and hubs are ok. I heard the sound before I changed the bearings.

Today it is snowing hard (in Indiana). I was using the Explorer in FWD and the sound is still there. One other thing I noticed is that when I let off the gas and just coast the sound is louder and I can feel a vibration in the steering wheel. As soon as I give the engine some gas I cant feel it in the steering wheel.

Thanks to pwrranger88 and ExploringNC for your responces.

 

[MEANEXPLODER]

u joints

 

[shaggymane]

Yes, both hubs were degresed and then packed with

The hubs are not supposed to be packed with grease. The two most common fixes are the stop bumper in the TC motor and degreasing the auto hubs. New Putting grease back in them is working against yourself.

hubs or new used hubs?
Have you had the front end in the air to confirm each one is locking?



Like they've said old sticking u-joints

 

[pwrranger88]

^+1 i always clean all the grease out and pour a little atf in and dump the excess atf out and put it all back together,

 

[cabraljf]

Ok, I will replace the U-joints. Might take me a while to get to but once I do I will post the condition. Hope this works.

Again Thanks to everyone for the responses.

 

[Tony H]

As mentioned. These Auto hubs should not be greased. pour in and dump out some ATF and that's it.
Your last post does make it sound like 'U' joints check the drive shaft and the joints at the axle ends.

 

[cabraljf]

Problem Solved!!!

I know it took a lot of time to get around to fixing the X but here is how it went down.

Checked all the U and ball joints to find out that they are all still pretty solid (not bad for 156k mile 91').

It turned out to be the centering yoke on the driveshaft from the transfercase to the front differential. Changed it out and everything is great.

 

[Tony H]

So the Splines were shot on the Yoke and it was skipping on the Shaft that comes out of the T-Case?

 

[cabraljf]

It was the bearing, I think it is called the centering Yoke. I can look at the receipt and post a part number to clarify.