97 Ford 4.6 with 4R70W 4 wheel drive and 22000 miles. When getting on the freeway tonight I noticed a loud momentary screeching noise when the transmission went from 2nd to 3rd gear. The shift felt normal to me. This was under load and accelerating up a gradual hill. This continued to occur in all the next moderate acceleration attempts. I'am not very knowledgeable about trannys but it sounded like the bands were slipping. I never drive it hard and most of my trips are 10 miles or less this time of year. So I took it out to the country and ran it hard for about 20 minutes with full acceleration and lots of shifting. The noise is now gone. Transmission fluid changed to Mercon V at 20000 miles and full and bright pink. Any thoughts or suggestions?

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1997 F150 EXtended Cab 4X4. 4.6L. 3.55 with tow package. K&N Filter. Flowmaster Delta 50 with dual exhaust out the back and 3.5 inch tips. Kenwood CD player.

 

One simple thought. What about your serpentine belt slipping? Does it screech for a moment at a cold start up if parked outside overnight/day?

 

Tom S- Several people have posted similar noises. Many at full throttle shifting in to 2nd gear. Sounds like belt screeching, as previously mentioned. Others have used belt dressing, replaced the belt, checked/replaced the belt tensioner, and left it alone. It shouldn't be the bands or clutches slipping.

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2000 F-150 XL, RC, LB, 5.4L, 4R70W, 3.55LS,
Class III tow, Payload #3, & Convenience pkgs.,
4-wheel disc/ABS, Chestnut/Parchment 40/60,
Ford bedliner w/Paintsaver & gas/wheel/spare locks,
K&N F.I.P.K. w/Outwears pre-filter, Superchip,
Dynomax ultra-flow welded 3" cat-back w/ 3" Y-pipe,
Hellwig front & rear anti-sway bars, Rancho RS 9000s,
Mobil 1, K&N oil filter.

 

Thanks for your responses. Sounds like the belt tensioner. It has been squaking momentarily in the morning on first start up.

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1997 F150 EXtended Cab 4X4. 4.6L. 3.55 with tow package. K&N Filter. Flowmaster Delta 50 with dual exhaust out the back and 3.5 inch tips. Kenwood CD player.

 

I had the exact same symptoms with the addition of an obnoxious "squalk" on initial engine start. Rochester's famous Ford auto collection (yes,, sarcasm!), installed the following: F75Z-8678-AA Idler assy, and F75Z-6B209-AA tensioner assy. They advised me that the tensioner assy was not releasing properly which causes the "squalk" at any abrupt rpm change, which covers gear changes as well as initial start up. Yep the belt was pissed and was crying out for attention! Quiet as a mouse now. WOW, this means that it was repaired with only ONE VISIT!!. Nice!. I hope this helps. C-ya..
Rick..

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"99" F-150 4x2,SC, med red / silver, 4.2L, auto, 3.55's, 265x16's premium snd w/cd, 4 wheel antilocks, leer "too heavy" matching cap, Mobil 1.
"Gutless thing!!"