Hello all - I've got a strange noise coming from "under" my '94 F-150. It's a 5-spd., SWB 2WD, 300 I-6, and I'm getting worried about the problem.

It's a ticking noise, consistent with engine speed coming from what sounds like the bell housing (or bell housing area, I mean closer to the front of the truck than the back, it's not a rear axle type sound.). When the clutch is out and the truck starts rolling, the ticking starts and gets progressively faster as the truck accelerates. When I very first heard it I was in a parking lot and play'd around with it in reverse and first gear, so I thought it was a wheel bearing going bad, *BUT*, when I push in the clutch, the sound stops. So much for the wheel bearing idea. After shifting gears into 2nd or 3rd, when I release the clutch, the sound starts again. Again, slow but increasing in frequency as I go up through the rev range. So the fact that it's consistent with RPM's and not ground speed again rules out W/Bs.

"The sound" sounds like a metal radiator clamp was tie'd around a shaft or something, and the pigtail is slapping metal everytime the shaft spins. Does that make sense? I first noticed the problem around new year's time, about 1200 miles ago, and it's progressively getting worse. At first it was only noticable in maybe 1st, 2nd and reverse, but now it's getting so loud I can hear it up thru 3rd or so.

Also, I'm noticing progressively less and less resistance in the "feel" of the clutch pedal... feels more like an import car clutch than an American truck clutch. Sometimes I push the pedal down and damn near put my whole leg thru the firewall, thinking "Where's the resistance?"

Finally, the truck is developing a vibration I can feel in the floor boards and steering wheel at high speed, like say 55 MPH or higher.

I took it to a Ford dealer near me who swore up and down they drove it and couldn't hear a thing, nor figure out a damn thing wrong with it, said it ran like a champ. I am convinced they are clowns, especially after I was pulling out of the parking lot and could distinctly hear the clicking. People were staring at me 'cause the truck was so loud.

I know internet diagnosis is next to impossible, but anyone have any ideas of what could be causing this and/or what I can do about it?

-Howard

 

had a similar clicking sound with my 300. was due to a exhaust leak in the manifold and such. couldn't be heard at idle and stuff, but put the hammer down, and its sounds rather loud, and people wonder... problem was inside the exhaust manifold in the block, and cost upwards of a grand to get fixed. as for the clutch, i'm having the same problems right now, and i'm, as well as maechanics are dumbfounded, say nothin is wrong.
just a ford thing i guess

 

Could be the clutch throwout bearing but usually that is more of a squeeking noise. If you can make it happen consistantly make a dealer technician go for a ride with you when you drop it off so you make sure they here it. They should be able to drive the truck on the lift with someone underneath it to locate the noise.

-Jon

 

Does the noise occur when you're in neutral?

Also, when is the last time you checked the fluid level in the clutch master cylinder? Has it gone down any?

 

Nope, all quiet when I'm in neutral, but it does make it easier to hear the P/S pump whine when the underside of the truck isn't making all that noise.

Clutch M/C was fine, a little low, I added some DOT 3 to it, but no more than .5 - 1 oz.

The problem has not changed at all. Still noisy under there, clutch is weak (offers no resistance when I push it down), mild clutch chatter/shutter when the truck's cold, and that vibration present at 60 MPH+.

I know this'll work itself out some night when I'm stranded on the side of the highway at the terminal end of a 1/4 mile trail of transmission fluid/parts.

-Howard

P.S. - I should flip 100,000 miles some time next week or the week after...

 

See, this is where it doesn't make any sense. The noise is rpm related, so it has to be something between the engine and the countershaft in the transmission. After that, everything is speed related.

When you push in the clutch, the noise goes away. That means it's something between the clutch disc and the countershaft, because they aren't forced to spin when the clutch is pushed in.

When you put it in neutral, the noise goes away, but the entire section we just identified as being the suspect problem area is now being spun by the engine, which means it can't be any part of it.


Bottom line is this; I don't know of anything that spins at the same speed as the engine rpms in gear, but not in neutral.

I'm stumped.

 

Maybe that's why the dealer techs passed on the problem?!? I dunno either, but it's worrysome for me...

It is a strange situation for sure. When I'm rolling along in gear, accelerating up through the rev range, I hear the ticking, and the frequency of the 'ticks' is consistent with engine RPM (meaning the faster I rev the engine, the faster the clicks become). But when I push in the clutch to switch gears, the noise stops. I grab the next higher gear, release the clutch and apply throttle again, and the ticking returns, this time slower, because the engine RPMs have dropped to reflect the new gear selected.

If I'm rolling along, say down an incline at 30 MPH, and kick it into neutral and release the clutch, engine idling, there is no noise. Despite revving the engine or not, the ticking sound is not there. It's a sound occurring when the truck is in gear and moving.

The fact that it occurs while in reverse as well also throws more mystery into the situation.

I don't believe it to be a squeaking noise, it's more a ticking. But I suppose it could be a quick, succinct squeak that's so fast and loud I'm mistaking it for a ticking or clicking.

I wish I was more a mechanic and less a graduate student.

-Howard

 

Well, I am a mechanic, and I'll lay it out for you the best I can. Maybe that will help (I hope!). The engine is physically attached to the flywheel at all times. The flywheel is attached to the pressure plate at all times. That's where it stops, so if it made the noise all the time, no matter if it was in gear or not, or the clutch pedal was pushed in or not, it would have to be something between the engine fan and the pressure plate. Understand?

Okay, next is the clutch disc, which is physically attached to the transmissions input shaft. On that shaft is the throwout bearing. The input shaft is permenantly connected to the countershaft inside the tranny by gears. In other words, everything from the clutch disc to the countershaft is always connected, so when one part of it spins, the rest of it spins. It spins freely when the pedal is pushed in, but is driven by the engine when the pedal is out. In other words, when the pedal is out, everything from the engine fan to the tranny countershaft is solid, and connected, and spinning at the same rpms (unless the clutch is slipping). When the pedal is in, they are two separate items. With me so far?

Okay, next comes the tranny output shaft, which is connected to the countershaft via gears only when the transmission is in gear. When it's in neutral, it isn't. Going the other way, it's permenantly connected to the driveshaft and rear end via u-joints. The rear end is physically attached to at least one axle at all times, so everything from the tranny output shaft to the rear wheel(s) will always be connected, and will always rotate in relation to ground speed. It is the different combination of gears inside the tranny that determine the speed of the output shaft through to the wheel(s) in relation to the engine through to the countershaft.

Since the last of the three sections only spins the same speed as the engine rpms in one gear, and your noise occurs in all gears, it can't be caused by anything from the output shaft all the way to the wheels.

Since the noise goes away when the pedal is pushed in, it can't be anything between the engine fan and the pressure plate.

That leaves the second section, between the clutch disc and the countershaft. It always spins when the clutch pedal is out, regardless of what gear it's in, including neutral, so if the noise goes away in neutral, it couldn't be anything connected to the first two sections.

This is a real paradox, and is really bugging me.

 

Damn, I hope I'm not keeping you up nights!!!

Feel free to drop on by the great state of South Carolina anytime to check it out, I don't mind.

Want more drama? It didn't make any noise on my drive home last Wednesday. No ticking, no shakes/shudders, nothing.

Now I consider it an "intermittent" problem.

I'm gonna start drinking, maybe that'll fix it.

But seriously, thanks for the concern, I'll let you know what happens with it (or to it).

-Howard

 

Oh joy.



Sounds like a plan to me. lol.

Keep me posted!

Take care,
~Chris

 

Guys, from the sound of the problem and when it shows up and doesn't. It could be the main shaft in the transmission. JMC currently has that same type of sound and was told that the shaft was chipped or something like that. I have left a message with JMC to check out this post to see if his sounds similar to yours. He should be along soon. Oh, he has a 2000 F150, Supercab, Shortbox, 4.6L, 5 sp. truck.

Have Fun & Keep on Truckin'
Dean

 

Sounds like you've got broken springs in the pressure plate to me.
Maybe not, but I've heard these and stranger noises caused by this.

That would also explain your weak pedal pressure.

 

That makes sense. it would also explain why the noise goes away when the pedal is in. I think you're exactly right. Damn. How did I miss that? I must be losing it. I think I thunk too hard. lol.

 

Broken springs or fingers on the pressure plate are a possiblity. The bottom line is that if the clutch is chattering and slipping it needs to be replaced anyways. Once you pull the trans out you'll know for sure what's up.

-Jon