Thumping noise from the front end.

I was wondering if anyone out there may have experienced the problem I'm having. I have a 97 Explorer XLT 130,000 mile auto 4.0 liter automatic. This thing has done everything I asked it to do so I want want to keep it around as long as possible. Here's the problem:As I drive down the road under normal conditions a thumping noise starts at a low speed and gets more pronounced the faster I go. It is not a tire slap. When I put it in 4 x 4 low I'm OK until I try to turn. Just in Idle I go forward about 10 mph as soon as I turn the wheel I hear a loud groan and the truck comes to a stop without touching the brakes. If I give it gas to speed up it just groans and thumps louder. Since I tried that last week I think the thumping noise is getting louder now going down the road. Any Ideas or suggestion would be appreciated. Thanks. Jack

welcome

Welcome to this forum! I've moved your thread into the stock 95-01 section. Check the caliper bolts, wheel bearings, CV axles, ball joints, and tie rods.

Id shoot for Front axle shafts also, look for grease, or a torn boot. I would think it would be more obvious, sounds like you lost a u-joint in the front axle.
Easy way to inspect is turn the wheels Full left, get out with a flash light and look inside the arm area, same with the right.

mine a 2000 ex does a thump but not in 4x4, garage told me the bearing in the axle next to drive shaft is going bad. The wheel bearing have been replace and the half shafts, front drive shaft feels solid. IDK

Hey guys, Thanks for the quick replies. I don't believe it is anything loose like tie rods or ball joints, but it sounds like it coming from the drive train up front. The noise is very loud in 2wd at 35 -65 mph. With the car in drive at idle in 4wd (high) going forward at 10mph all is good. As soon as I turn left or right the front end will bind up and the truck will come to a stop.
I did a lot of reading on this site & now I'm leaning towards a bad Viscous Coupling (VC) or something up front. So, can I remove the drive shaft from the transfer case to the front axle and still drive the truck.

unclejack said:

With the car in drive at idle in 4wd (high) going forward at 10mph all is good. As soon as I turn left or right the front end will bind up and the truck will come to a stop.

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This is somewhat normal, you shouldn't be in 4WD High or especially 4WD low on dry ground. This information is also in your owners manual.

On dry ground you will bind up the drive line when turning in 4WD.

I suspect that if you've been doing this something in the drive line has failed.

My X is equipped with 4WD auto, 4WD high, & 4WD low. My Four Wheeling owner's supplement says do not use 4WD on dry, hard surfaced roads (except models equipped with Auto 4WD or AWD). Must be something magic with the Auto 4WD or AWD. I use 4WD (either high or low) when I pull my boat out of water. It's easier on my transmission, the owners manual says I should use 4WD occasionally during the year and recommends using 4WD low to pull a boat out of the water, and after I'm off the ramp I might go another 100 to 200 feet on dry (damp) hard road surface in 4WD. I never though of that as a problem mostly because I've been doing that for 13 years with this X and 10 years before that with my Bronco. Maybe 10 to 15 times per year.
The owners manual also says I should not drive faster than 45 mph when towing my boat. Tell that to the 18 wheeler on I-95 while he's blowing his horn and giving you that one finger salute.
As far as the wheels binding up and stopping the truck when I turn in 4WD I either didn't notice it before coming off the ramp or I really believe its something that started since I noticed this thumping noise.
So far I checked the rubber boots, they are OK, no cracks, no grease on the outside. Almost too clean for a truck with 130,000 miles. I tried to wiggle the outer cv joints while it was in Neutral and everything felt tight both sides. This weekend I'll pull the front wheels hubs and check (re-pack) the inner and outer bearings. Thanks for the suggestions so far & keep 'em coming.

It's the front differential (in the axel). You might have broken teeth.

PS: You don't have a VC - only the AWD has one. That is part of a true central differential, unlike yours that have a rigid coupling in the transfer case.

Hey, Sonic67, thanks for the heads up on the AWD. you're right & I didn't think of that. I guess I should check the front diff for metal chips.

Did you check he ujoints in the front shafts? typically, when in 4x4 on dry ground youll hear tire chirping, unless you broke something. if it was your diff you would only hear noise when you were in 4x4. But you are hearing it all the time, i would start simple, and work from there. As far as i know you dont have a fully locked front end, you may have a posi in the rear, but the front will be open, meaning if you jack up your front end you can grab the passenger side wheel and turn it, and the driver side will turn in the opposite direction. if your diff was junk it would be junk all the time, not just when you turn the wheel, which points back to the U-joints (or CV) joints in the front end. A rigid coupling would imply a "spool" or fully locked front end, ive never seen one from the factory, because an inexperienced off roader would have an incredible amount of trouble on any kind of slippery surface.

same problem here

just passed 170k on my 97 sport 5spd.
last few days noticed a thumping noise and vibration (feels like someone is hitting something under the car with a 3lb. sledge) coming from front end when vehicle is moving above 15mph or so...thumps are continuous and increase with speed...whether accelerating or decelerating or coasting noise is there.

Today it was so loud almost pulled over on way home from work. Engine runs fine, car idles perfect...must be driveline related. Looked underneath when I got home...wiggled anything I could find...everything felt firm. Did notice some grease on passenger side around the axle.

Not sure if it is relevant but, last few days have been very cold...today was a bit warmer and noise seems to be getting worse.

(Had an old BMW did close to same thing few years back..turned out to be center support bearing on the drive shaft. When I got underneath and shook the drive shaft..the rubber surround on the bearing was ripped and allowed the drive shaft to bang against the tunnel. Didn't see anything quite so obvious under the explorer)

Together we will get through this!

on the v8 awd models the front driveshaft makes the thunking noise at any speed. - It can be verified by removing the front ds.

Not sure about the v6 4wd - but I would think it could be the same scenario - a bad u-joint - again the best way is to drop it - if it stops then you have narrowed it to either the front axle or the ds

tweety said:

(feels like someone is hitting something under the car with a 3lb. sledge)...must be driveline related. Looked underneath when I got home...wiggled anything I could find...everything felt firm

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Crawl under the truck enough that you can see the boot of the CV-joint of the front driveshaft where it connects to the transfer case. If you have a CV-joint that is, and see if it is torn. If so search the forum for "front driveshaft" and you'll get a lot of information about it.

CV joints will be between the tire, and Diff, u joints will be between the t case and the front diff, the differenct between the two is because of the working angles, remember AWD, and 4x4 ARE different, ALL wheel drive is all the time, 4x4 is only when selected, he only has noise when in 4x4

little more info

my truck is the awd 4.0..and I did the brown wire mod on it about a year or so ago...I usually have the awd switched off 98% of the time. Primarily only engage it from standstill when trying to drive out of or through heavy snow.

latest...

Hey guys, the saga continues. The noise now seems to have subsided a bit...also no longer feels as much like something is heavily impacting the vehicle. Now seems like something is lightly impacting and then rubbing or grinding under the front end..but very loud and noticeable even from inside with the radio on. The noise is still continuous above 15mph and increases with speed

Ideas?

(Sorry uncle for hijacking..but thought any info would be beneficial for both of us.)

anyone still following this...

guys I replaced the front passenger side cv axle shaft...still rhythmic clunking noise above 20mph that increases with wheel speed (not rpm's)

Started thinking maybe u-joint in driveshaft..pulled front driveshaft, u-joint seemed fine. Drove around the block with front driveshaft out..still clunking noise from front passenger side. Could this just be a wheel out of balance? I'm running out of ideas and parts to replace.

Thanks for all your help.

I have the same problem.. its been going on for about 4 yrs.... I have replaced hub assemblys, cv axles,tires,Ect...
Im all out of ideas..

tweety said:

I'm running out of ideas and parts to replace

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Vibrations can travel up and down the driveline in deceptive ways. Don't rule out the rear driveshaft u-joints. Best advice I can give is to crawl under it and look at the entire underside for leaking fluid or grease. Then test each wheel manually for play and noise, and each shaft for play.