Ok, I'm new to this, and someone might have already addressed this but idk how to search for it. I have an '01 f150 supercrew 5.4L. Recently while pulling a heavy load on a trailer I began smelling what smelled like a burning clutch. It shifts fine and doesn't slip. It functions perfectly as it should and fluid level is good. But now even without a load, if I accelerate hard up a hill I smell that burning clutch smell. Could it be anything other than a clutch pack? (First Ford I've owned so I'm assuming these have clutch packs too.) I believe it has a 4r70w transmission if my research is correct, but i may be mistaken.

 

Auto's don't make that same smell. The clutches in an auto are saturated in ATF, and deep within the trans. However, brakes will produce the same smell. Any chance you have a brake hanging?

 

Don't forget to check that parking brake as well, if they get stuck applied, or slightly applied, you'll get that smell as well.

 

Negative. I can drive it all over on level terrain with no smell. Only when I AM pulling a load on a trailer up a hill, accelerating hard with a load or when I accelerate hard up a hill without a load. No smell any other time.

 

I get that complaint often...
You might have been smelling someone else's brakes on that hill?
Do check the trans fluid for burnt smell, just for GPs

 

An overheating automatic transmission definitely has a similar smell to friction clutch/brake overheating smell. I'd just check your fluid first of all...is it brown and how does it smell? THAT will tell you a lot. Should be red and not have anything but an oil smell. My guess is that you've toasted your tranny...whoops, probably can't use that term anymore ...I mean your transmission and under load it is letting you know. Type a search in on YouTube for this...you'll find dozens of videos.

 

That's what I was afraid of, that I've burned it up. But the fluid levels are good and it a red color. There is no grinding or slipping of gears. I've never git into rebuilding auto transmissions because back in the day, they had dozens of all similar sized bearings in channels and the wrong one in the wrong channel spelled disaster. A YT video i watched on the 4r70W looks like they no longer use those bearing like they used to. My question is now, what would I replace to rebuild it? This is my primary transportation so I cant afford to leave it out whi l e waiting in the right part to come in, I need to be able to pull it, rebuild it with the right part already on hand and then reinstall it in the same weekend. I'm on fixed income so i cant afford to just go and get a new transmission. I dont wanna order a bunch of parts I dont really need. I need to know the MOST likely culprit to be the problem. I've found a master rebuild kit for like $300 but if it sounds like something a broken spring under the valve body or something, why spend all that on parts I don't need. See what im saying?

 

Seems like much worry and planning over only a smell. Could be something burning off the exhaust system from the extra heat when loading the engine.