banging under driver floorboard HELP

[djblackout]

vehicle: 1998 explorer sport 4wd 4.0L

Ive had this problem for a while now. It's just gotten worse. Anytime I accelerate from a stop and go over 2000 rpms, this thudding under my feet start. Sometime if I give it half throttle and keep the revs around ~3000 rpms, the thudding will go all the way up to 3000 but then stop... If i drive like a granny, and never go over 2000rpms it doesnt thud, unless the car is under a load (going uphill).

If I turn the dial to 4 high, the noise is there the whole time it's in 4 high. thud thud thud thud thud.

I checked my trans fluid, and it was kinda low.. so I added it to the recomended level with regular atf.

PLEASE SOMEONE HELP ME! This is my daily driver

 

[djblackout]

someone posted a video AND THIS IS THE EXACT SOUND!!

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

 

[brianwsnc]

It's a classic center support bearing noise. I am not sure your drive line design, but when the center support bearing goes out on the drive shaft, it will allow the drive shaft to oscillate and bang around until centrifugal force centers the drives haft at higher speeds

 

[djblackout]

Can this cause a catastrophic failure, or is it okay to drive around with it like this for now? I need to drive an 8 hour trip coming up.

I'm pretty handy, i've replaced wheel hub bearings, struts, various manifolds on ford focus and focus svt's, but never worked on this car yet... how difficult is it to swap out the bearing?

Would it involve dropping the whole tranny?

 

[swetrid]

You need a front driveshaft, Very common problem.

 

[djblackout]

if the front driveshaft breaks, is the car still operable? Lets say I'm bringing an 800lb load of wood home, does that just make my car rwd? It's not going to leave me stranded is it? I'll have the money to fix it myself, or take it somewhere in a couple of weeks... but until then I have an 8 hour trip coming up.

 

[djblackout]

also, does anyone have the "name" or "code" of my transmission? So that I may read up a little bit on the process? I have a 98 Sport XLT 4.0... not sure if it's the sohc or not. I assume so, but not 100%. Didn't come with a manual or anything. :/

 

[PopRichie77]

I wouldn't drive 800 miles like that, sounds like the u joints are bad and they can be replaced. If ether u joint lets go the front shaft will fall down on the ground, very bad if the front one lets go. The rear one is a CV joint.
Check the cover on top of the engine if it says SOHC then it is a 4.0 SOHC engine.
The trans is a 5R55E, if it is an auto?

 

[djblackout]

No it doesn't say SOHC, just 4.0L , so I guess its the OHV engine. and yes it's an auto. I am going to attempt and do the u-joints tonight. I wouldn't think it's too hard of a job to do. (hoping) Ill search and hopefully find a write-up on here.

thanks to everyone so far for helping me!

 

[PopRichie77]

Google--How to replace a U joint. You will find a lot of information.

 

[adambant]

Or you could just remove the front driveshaft like I have since the spring, until you get it repaired or replaced when you get the money. HOWEVER, this is ONLY if you do NOT have AWD, as AWD will roll away in Park if the front shaft is removed.

Adam

 

[djblackout]

i have 4x4... would it still roll away?

 

[drdoom]

i have 4x4... would it still roll away?

You should add that info to your profile, it helps other members help you if put your specs in.

 

[djblackout]

^ you speak the truth. just did

 

[ozmedia]

try the front drivesjaft U-Joint.

I have to agree with PoPRichie77. I've seen this one in the shop a few times and, while it is rarely the whole front shaft that needs replacing, usually just throwing in a new front drive shaft u-joint does the trick.

Worth the try at a cheap fix first anyway.

 

[djblackout]

are there any good writeups on how to do them? I'm so used to just FWD cars that I just want to visually see what I'm doing, before taking things apart. I'm very confident in doing repairs... I just like to be cautious.

I tried finding a write up on here, but came up empty. Thanks in advance if anyone can find me one

 

[95exploresport]

This one by Turdle looks good:

http://www.explorerforum.com/forums/showthread.php?t=191429

type in the search space above what your needs are and a sheat load of posts will come to your needs.