Lately I have been getting this vibration at freeway speeds, well when I let off the gas and start to come down in speed. Some times its more noticable then other but is still almost always there. It happens when I am at speed 60+ and let off. Does that sound like bad U joints, bent axle, what? Also I dont notice anything different at street speeds, the only other weird thing is when I back up while turning I get a vibration, at first I though I was just rubbing but Im not. Had had gears put in not to long ago and they whine some at 50 MPH do you think this vibe could be comming from the rearend like a bad gear set, bad install, bad barrings? I have RP in as the oil

 

I experience a vibration in my 2004 SCAB at 72mph. When I drop down or go up, it disappears. My brother says the problem is in the tires. Could be, they are the original with 57k on them. Wait, what was I doing at 72mph? DOH.

 

I think it is probably your gears. I had something similar happen to mine. It was just a bad set or it may be from driving hard that you tore up your spider gear...

 

Can you feel the vibration in the seat of your pants or in the steering wheel?

 

Any one that wants to say tires dont, I have had this truck awhile now and dealt with the tire issue. This is strictly mechanical, either a hanging rear brake (already checked but didnt find anything), a bad gear set or warn u joints.

What do you recommend etrevino? Pulling my rear cover and looking for metal or wear? I dont want to waste that RP it has less the 1k miles on it. I had my gear guy drive with me and he said everything was fine. This is my second gear set, the first was really noisy and now this one is really starting to whine at 50 MPH. If I can determine it is my gears ill just take it to 4wheelparts and have them redo it the guy that cut me that deal has just been a pain now (he thinks Im too picky, he says gears will whine) and either doesnt know how to set up gears or uses cheap gear sets. I though it was my u joints but I checked and I dont get any play.

 

Sounds like a bad gear set.

 

It has all the symptoms of a bad u joint but then they all seem tight, I did just remove it and grease the slip joint last week about the time this came on, is it possible I reinstalled the d shaft wrong Ive done this like 3 or 4 times now with no issues tell now. Is there a master spline on the slip yoke or is there no way to install it wrong

 

I'm not sure, I always mark my driveshafts to make sure they go in the same way they came out. I'm wondering if maybe your driveshaft is out of balance? .. I know you said your wheels are fine but maybe one of them is out of balance, after you were jumping your truck!

 

Just curious what rims do you have? Been fighting this battle with ford since aug on my 07. After one dealer replaced drive shaft last mon at 1' oclock and said it was 100% perfect, the next dealer said he felt something still and hour later. Needless to say the second dealer is replacing my chrome clad 17" wheels in the morning because 3 of them were coming apart. He says this is the reason they will not balance out.

 

No this feels completely like my drive shaft has bad u joints but they are still tight so what else would cause this. I have helo max wheels. Does anyone know about the drive shaft having a certain way to go back in? I know the dealer makes them when installed ill check if I can still see that original mark I used to go by. This was the first time I didnt look for it

 

this happened to me but it went away after i balanced my tires

 

Sorry Ethan just got home. I took my truck around to a couple different shops and got them to listen/feel it and they said it was the gears. I took it back and the guy replaced them for free. I really don't know enough to tell if anything was wrong. Obviously if they were wearing wrong I should be able to tell but otherwise it could be something really small. What I actually did, I just remembered. I jacked my truck up by the axle (I know this is really unsafe) and had my dad get inside and let it roll. I got behind the truck and listen for the noise and I narrowed it down to the rear end. Maybe try another gear shop? Good luck.

 

yeah I jacked my rear up and put it in drive too looking for wheel wobble or anything that could lead to the vibe, I dont know much about gears so I dont know if I pulled the cover if i would know if anything was wrong other then metal in the pan, the guy that put them in already put another set in and now has been less then help full I am just to picky and everything is fine

 

tires out of balance?

 

Ditto.

Same thing I experienced except it was a small sized pickup a few years back. A balance and alignment bought it back to new.