i've noticed this with all ford mod motors i've been around after a few years. 5.4s and my 6.8. somtimes at WOT shifts i'll get a quick sqeel from the belt slipping. doesnt do it any other time. the belt looks good but i think it may be factory so its on its last legs i'm sure. is there any cure for this? its funny it doesnt do it all the time though. anyone else have this issue? i may have it alot more as i have mine at WOT pretty much everywhere i go lol the big girl takes alot of motovation.

just curious on others opinion of this.

 

You've got large rotating mass from all of the accessories and when the engine rapidly changes RPM,those items want to stay in motion. It's normal for the belt to slip a bit on crisp upshifts/downshifts. You can replace the belt with a Goodyear Gatorback and that will help eliminate some of the "squeak" noise.
JL

 

Mine does it too, every wot shift. I'm thinking that the belt is part of the problem, but I've also seen a number of tensioners that stick just outside of the range of movement where it operates. In other words, if you take a look at the tensioner while the engine is running, you should see it working back and forth in a narrow window of movement. I suspect that when I do get some time to check it, I'm going to find it binding up just outside of its range of operation...I hope. Please keep us posted on your results too!
Mike

 

I would change the belt and tensioner. It's under $100 for the parts.

 

Cooler weather like your location can exaggerate the condition as well. If you end up deciding to change the parts check your idler pulley as well. If there is any play in the bearings, rust on pulley surface or just a rough surface then you will want to replace it as well. You may not have a rust problem in AK but the bearing could still be an issue. A quick shift at higher RPM will allow for sudden slack and then tension on the belt, accessories, idler and tensioner. All of this can contribute to the problem you are hearing. Mine does not do it but I recently replaced the idler, tensioner and used a Napa belt - no issues at all.

 

O.K..help me out here - why would you want to do a "wide open throttle shift" ? What am I missing here ?

(my primary use of my V-10 X is to tow around 11,000 lb. loads on long trips involving both long up & down-grades.....)

? ? ? ?

 

Why not? Faster acceleration is one reason. Towing a load and getting it up to speed sometimes require WOT ,and of course at some point the trans is gonna upshift.
JL

 

You can add an additional idler pulley to the right of the alternator pulley. I've noticed that there isn't one there, but one can be put there. I had to use the bolt on the tensioner pulley when I replaced the tensioner. This could help.

 

Guess you tow much heavier loads than I do. I only tow around 11,000 lbs. True, with that load I dont win any drag races, but "each to his own".

 

So you never press your gas pedal all the way down huh?

 

You'd be amazed at how many people have been trained by crooked mechanics that going WOT will "hurt the engine".
JL

 

Im on my second V10, 1st was in a 01 F250, and now the one in the X, and I've had this happen in both. Have changed belts in both and it still happens, although not all the time.

 

i've delt with tensioner issues on my explorer so i figured that would be the next thing to look at. with the miles i'm at i think its time for both to be replaced. i figured this is what it is but even my grandpas f-150s from about 5000miles on would do this randomly. his new one is at about 40k miles and does it about as often as my excursion which seems random at best but it may have to do with the temps/humidity. it did not do it at all in the winter but this spring(temps up to 65F) i have noticed it.

thanks for the help guys and i'm glad i'm not alone in this.

 

Yes, I have had occasion to run at or near full throttle. Not very often. Perhaps you have much heavier loads to pull and/or a need to hear your engine scream ?

But then again, I only tow loads of around 11,000 lbs., so even with my gut-less V-10, and its 3.73 rear axle, I seem to get around o.k....

Seriously, of course the engine, transmission, and drive line can take full power shifts. But what's the point in "working" a machine that hard ?

Obviously, with that "high" ( low numerically) a rear axle ratio-gear, I lock out the over-drive - pretty useless except for the rare occasions when I am running without a trailer.

When you've been driving heavy trucks from the old days as long as some of us have, you develop a "feel" for the machine. You know when to back off on the gas a little bit, to make it easier on the works and/or you manually put the machine in a lower gear.

 

my reason? since i dont tow or haul anything. simple... to get up to speed as soon as possible with my truck. thats just how i drive. from any stop light up to the speed limit or 10ish above shes floored(so long as theres room/its safe..ect). its worse with the excursion then it was my explorer because it takes it being floored to get to speed when i want it to. everyone has a different driving style and thats fine i'm not here to debate that i was simply asking a question about my belt/tensioner.

i do drive my trucks hard, i fully accept that and whatever parts may wearout faster due to this. i drive her like i stole her and love every min of it.