Howling in 1994F150
 

My son just got a 1994 F150 ext cab 302v8,at,ps ,pb,with bout 196,000miles on it.Everything works great,fluid levels are good clean with no dirt. But the only problem is when you go down the road it starts to howl when it gets over 20mph,it does not shake,pull to one side or the other,and it only does it when you step on the gas.It's not in 4x4 and the hubs are not locked in.Tranny does not slip and there is no slop.Tires are good goodyear wranglers(wal-mart)specials.When you get going down the raod at hwy. speeds it doesn't get any louder it actually quiets down.Any suggestions.:-innocent

:-missingtDid you look under the hood for a pack of wolves?

not funny :-offtopic

my bighorns (mud terrians) "howl" i guess? but yes my MT's even when i had some street tires, there was a "roar" or a "howl" at low speeds then when you hit 60-70 mph it gets quieter than the lower speeds

when I started hearing howling from my truck, I was first suggested that the torque converter may be on its way out. I have since then identified source of howling sound as the hydroboost unit that runs my power brakes, but you don't have that, so in your case it may very well be the converter indeed. I am not aware of any way of checking it tho, I was told to just drive the thing and save up for a new converter in the meant time, so unfortunately this would be all the advice I can pass on to you as well :(

Altho on the other hand maybe there is a way to at least narrow down the howling sound's source - lift the rear axle off the ground and on jack stands, then put the truck in drive (4x4 disengaged obviously) and see if you can still hear the sound, and if you can pinpoint where it's coming from by crawling under the truck with it idling in gear and rear wheels spinning in the air (it will pick up about 30 mph on its own like that)...

Could it be a vacuum leak?

On my truck if I let the battery run down by leaving the lights on or something. The alternator makes almost a howl sound.

Check for a locked up fan clutch...

Almost for sure positive its your tires. Any type of "missing tires" will make a howling, humming, or whistling noise. It's caused by the large tread on the tires.

Front wheel bearing maybe? Mine are on there way out tried repacking them to no avail so now I need to replace them.

That is a significant clue. That would seem to leave tires out of it totally. And may also, unfortunately, make LCAM's idea of simulating road speed on jackstands not work in this case. As stepping on the gas with the rear axle up in the air, no load, the drivetrain will speed up immediately. But since it's so easy to do, may be worth a try anyway. But I would think the "howl point" would be gone through just like that.

Another idea would be to stick your head out the window, and try to determine if the sound is from front or back.

Also, having someone drive it past you at 20 MPH with it howling, you might be able to tell which end it is. Or get on a bike and have it pass you by. At just 20 MPH, you can race it with a bike! On a bike parallel to it, you would have more time to discern where it might be coming from. Just don't get target fixation and ride into the side of it :-rip

Torky2, if he has a helper he can actually try the two-foot brake-torque thing while on the jacks - bring the truck's driveline up to speed, then lightly apply the brakes while still giving the engine some throttle - not enough to burn up the brakes or overheat the trans, but maybe the load will be sufficient to make whatever's howling howl again. He can have his helper crawl under truck while he does that, then they switch places with the helper at the pedals and him under truck - then they compare stories, see if they'll both agree on a location where the sound is coming from...

a badly worn differential can also howl, normally under a load.

Check the oil level in rear differential first. I've had a couple cars that howled at speeds over a crawl only to find the rear end low on oil.

Having the same problem in my pickup, 88 F150 5.0L AOD 4X2.

Sounds like its coming from the passenger side front of the vehicle, only when I while on the throttle, Ill check the diff fluid though since I just picked it up not too long ago.

OP did you find out what was making the noise?

Well found my problem.

Took off the back diff cover to see how the gears looked because its got a bit of a clunk going from coasting to accelerating and a disturbingly small amount of fluid(closer to sludge) came out. Gears dont look too worn, but there is a fair amount of play in the spider gears.

Through it back together with a bottle of Lucas and the rest 80-90w, seems to have quieted down, still hear it a little but it was run near dry for awhile, oh well, I want to get a LS and some gears anyway.