Own a '98 F150 4X4 with 4.6L and 3.55 diff.
I have an intermittent noise coming from the the front driveline, as far as I can tell (definitely in the front). It sounds like a slight slippage of a driveshaft yoke and occurs usually after I've accelerated slowly between 1500-2000 rpms and then release the accelerator pedal. The noise is a click or metallic "slap". Sometimes it occurs when I begin to accelerate again, but mostly on decleration as described above. Sometimes it "slaps" twice (only on deceleration). When I took it to the dealer they didn't seem to hear it - definition of "intermittent auto problem": a problem that you know exists but which disappears when you hit the service lane of you local dealership .
Just wondered if anyone has had a similar problem and what they did to correct it. The problem has occured since day one (April, 98), is intermittent (as I said), has gotten only slightly worse in 10K miles. I'd say that it happens about 25-30% of the time during conditions I listed above. Any suggestions???
Thanks,
David A.

 

Mine has same sound, not all of the time though. Took it to the dealer, they heard it and said it was probably the spline, usually filled with grease at the factory, the sound is insulated. After using the truck a little the grease will come out and make the noise, they said not to worry about it. It's on my worksheet with them incase anything goes wrong in the future, I want it covered by the warr.

 

Thanks, W1!

Sounds like this is "controllable" to some
extent. I guess *if* this is the situation with mine, it came from the factory with a little less than enough lubrication, since I first noticed the sound on my way home from the dealership (but not on the test drive - as if subtle noises are even picked up during a test drive!)...
Is the spline something I can lubricate? I see an F-150 Maintenance Manual in my future... If it *can* be owner serviced, is there a grease fitting and recommended type of grease (or will standard lithium grease do the job)?

Thanks, again, for the info!

David A.

'98 F150 Ext. Cab Styleside - Lariat - 4X4 - 4.6L - 3.55 - Off Road Pkg. - Tow Pkg.

 

My Truck also had an intermittent clunk in the driveline, I brought it to the dealers and they replaced the whole driveshaft. I haven't herd a peep sense. If you do a search on the board you'll see there is many opinions on the subject. Good Luck

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Rex 99 F150 XLT S/C S/B 4.6, Auto, Solid Black, Dark Graphite. Santa Monica Ca.