I have a 2001 SuperCrew with the 5.4 and (I’m pretty sure) the 4R70W. I have noticed that when I jump on it hard off the line, I get a rather disturbing squeal or squeak noise on the 1-2 shift, and now that I think about it, I may get the same thing on the 2-3 shift as well. Much as I’d like it to be, it damn sure isn’t the tires, so I’m about positive it’s the trans that’s making the noise. I rarely run the truck that hard, so it’s not as though the trans is abused. Any ideas as to what the problem could be would be appreciated, as I like to show up at the service drive armed with some knowledge as to the problem, to avoid service writer BS.

Also, this thing holds a gear like no truck I’ve ever had. Often times in 2nd or 3rd gear, even full throttle won’t give me a lower gear. Is this the standard for this trans, or is it a malfunction? If it’s a standard issue, then does anyone know of a mod that improves this without major surgery?

Thanks in advance for any help.

 

That squeaking noise might be the serp bellt slipping at high RPM's. Is the flat side of the belt glazed? Is the tensioner holding very tight? Just some things to look for.

 

Had the same thing happen to me. It was the serpentine belt. If under warranty they should replace belt and tensioner. All I did was replace the belt and it took care of it.

 

Start cheap! Check the belt. Mine did it just like you discribed.

 

1-2nd serp chirp is very common. It's most commonly the belt rubbing off all of the paint from the new pulleys and ruining the first one. Others have reported weak belt tensioners and loose/misaligned accessories.

Gears not kicking down????=not normal; mine kicks right down at every opportunity. Good Luck !!

 

I have the same problem with my SuperCrew; the first time it made a screeching sound I thought it was the transmission too - it was! Actually, I just installed the TransGo Performance Shift Kit in my 4R70W transmission. At W.O.T. it screeches very loud from 1-2, 2-3, 3-4 every time. I'm not sure a new belt and tensioner will do the trick. I tried two different belt dressing sprays, but that did not help. I try not to do the W.O.T. thing very often; mostly normal driving. One of these days I plan to up grade the pulleys and belt.

 

Wow, I feel better now. My truck has done this since I installed the Transgo kit. I set mine on "stage2". I called them up at one point and they said they had never heard of the sound before, though. It still worries me a bit.

How long have you had the kit in? I'm at 25,000 miles now, getting ready to change the oil again. Not looking forward to it.

 

Thanks for all the assistance.

Additionally, I'm looking into the Transgo kit to improve the TERRIBLE shift quality. I realize the kit will firm the shifts, but will it make the trans kick down more easily too? If not, what will? (I find the trans often holds gears when I want it to kick down)

 

My truck has the screeching belt on 1-2/2-3 shift at W.O.T. also, but the thing runs like a r@ped @pe! With my open differential though if I go W.O.T. it will smoke the drive tire through the first shift if it does not hit a patch of rough and then it will wheel hop a bit...

 

Kliebeck,
Superchip can fix the poor shifting problems without opening up the transmission. Just go to the superchip forum and send Mike a post.
My truck shifts better then ever and kicks down much faster. If you don't want to have to use super fuel then ask him to tune the chip for regular gas. I personally like the additional performance very much. Well worth a few cents more for super gas.

 

I've had the belt squeal problem from day one. So far, they've replaced the belt, tensioner, and pully twice. Once before the install of the Superchip, and once after the chip had been in for about six months. The second time the service advisor at Truck City Ford in Buda told me it was sqealing because of the Superchip. He also gave me the act about the chip voiding my warranty, but that's another story. I'm beginning to think it's not the serpentine belt, but something in the transmission. Now, the transmission will slip out of gear if I'm going about 45-50 mph with my foot just barely on the gas. I think it's getting confused on the shift up into OD. When it does shift back into gear, it makes the exact same belt squealing sound as at WOT. Hmmmmm....... Oh well.......this is why I have an extended warranty.