Clunk from under front floorboard- could it be the tranny?

[bigDerk]

Well go figure, just as I spend more money on my truck (over $300 on gears and a limited slip), I have what might be another problem.

Here's the deal... I was in traffic, pretty much bumper to bumper, and when I would roll from a stop, idling forward and under very little acceleration, sometimes I would hear a "clunk" that I could also feel through the floor. It wasn't loud, but it was audible, and it sounded like it was pretty much in the center or maybe to my right, somewhere around the firewall/front suspension area. When it would happen, it would clunk pretty much once for every complete turn the tires would make, that's about how often it was, and it would only happen under 5mph or so.

At first I thought it was something in the suspension, but I heard it when I was on flat road, going straight, with practically zero suspension movement. A friend of mine mentioned that it could be the torque converter. I don't know anything about transmissions, but could this be a sign that the tranny is about to go? I know that Explorer transmissions are notorious for having problems around 75-90K, and mine has 76K on it... and I haven't exactly babied this truck.

Any thoughts? I wanna get this figured out before I go dishing out hundreds and hundreds of dollars more to install the gears, I don't wanna be stuck having to pay to have my transmission rebuilt.

 

[BoatsRcool]

sometimes on my street when i slow down down the hill, i hear a clunk, like something barely moves foward.. right in front of me in the middle.

but i have a brand new transmission..

 

[RTStork]

Mine has a similar sound too. I haven't located it yet.

 

[dbarale]

Check your radius arm bushings. If they're still the original ones the one on hte passenger side is probably gone because of the heat from the catalytic convertor.
They re cheap, about 30$ for poly ones but they're a pain to replace...
Good luck.

 

[hskrbkr]

I get a clunk right under my left foot every time I come to a stop. I am fairly certain it is a radius arm bushing problem. Mine need to be replaced. Don't know if this is the same problem you are having. Mine doesn't do it constantly - i.e. every wheel rotation - only when I come to a stop.

 

[dbarale]

After reading your post again I just noticed that you're talking about a clunk at every wheel rotation.
That doesn't sound too good. Could be a few things.
From what you say it sounds like the front axle is engaged. Do you have automatic or manual hubs?
Do they dis-engage correctly?

 

[BoatsRcool]

i dont have one every rotation.. but yeah . i have new radius arm bushings.

 

[zensius]

I've got the same radius arm problem on the passenger side. Can these things be bought at any parts store or Ford only?

 

[Arnold D.]

On newer explorers, look at the torsion bar adjuster. On top of the adjuster
is a rubber pad insulating the adjuster from the mounting point. Both of mine were worn thru on my 96. After dropping the adjuster, I glued another rubber pad in place and it eliminated the noise.

 

[bigDerk]

I had the radius arm bushings replaced about 5000 miles ago, can't be one of those, they're both still basically perfect. My truck is a 94 so it doesn't have the torsion bars either.

The noise doesn't come with every wheel rotation, but when it did happen, it would do it two or three times as I was accelerating, pretty much in pace with each rotation of the tire. It would only do it until I got to 4 or 5mph, and then it would stop as I sped up more. I know for sure the hubs are not engaged, I just installed some Warn manual hubs a week ago.

 

[Clint]

check your front wheel bearings i had a similar problem with my truck

 

[KEbert]

Mine does the same thing. When I am in low range and crawling with it, the clunking is very loud when I give it a little throttle, then back off it. Try this and see if yours is more noticable.

 

[bigDerk]

KEbert, this is when 4WD was not engaged, driving on the street. I also hear the noises when using 4WD, but I've always had that. This noise while barely moving in 2WD has just begun.

I will check out my wheel bearings, that's something I hadn't thought of...

 

[dbarale]

Don't get mad at me... Are you sure about the installation of the hubs.
Did you have the bearings tightened properly, or may be they just need to be retightened?
It wouldn't hurt to check.

 

[bigDerk]

I'm 99.9999999999% (yeah, that much ) sure that the hubs are not the problem. I was very careful when installing them, and made sure to torque everything to the required specs. Also, judging from the sound, and the fact I can feel the "clunk" in the floorboard, makes me think it's something closer to the body of the truck. Thanks for the input though, I'm not even sure if it's anything to worry about.

 

[KEbert]

Mine does it in 2WD too. It's just that in 4WD it does it CONSTANTLY. I think it is the radius bushings. Hell I don't know!