Vibration When on Throttle??

[powerstroker019]

I have a vibration when hitting the throttle between 30 and 65mph... The vibration only occurs when on the gas pedal but when i let off it stops.. i have replaced the carrier bearring on the driveshaft and checked all the u-joints and they seem to be fine... I was wondering if anyone had any ideas of what else it could be... Transfer case?? Tranny?? Rear End??

[Tony V]

I would say its a ujoint. I've twisted 2 driveshafts now and thats the exact feeling it gave me before it went kaboooom

[prater199]

could be a torque converter

[F350Bigfoot]

I am having the same problem and cant figure it out. I can barely touch the throttle and it starts and as soon as I let off it stops. I wish I knew some one that has a dyno just to put mine on and listen to it running other than inside the truck. If you figure anything out let me know.

[cghoerichs]

Have you greased the splines on the drive shaft? It is a known problem with F-X50's and has the exact symptoms you have. The drive-shaft is a 2 piece drive shaft and has no way of being greased except to take the 2 shafts apart. Chock the wheels. Mark the drive-shaft so that you can put it back together balanced. Drop the rear ujoint. If you remembered to chock the wheels and are still alive, cut the band around the boot where the shafts are joined and pull the drive-shaft apart. Apply a light coating of grease to the splines. Too much grease and you'll get a pressure lock that can break the driveline. Put it all back together and see if your problem isn't solved. You can use a zip tie or even a hose clamp to hold the boot back on.

[F350Bigfoot]

I just greased the drive shaft and checked my u joints and it still does it. The u joints were good. Any other ideas without ripping out the drivetrain and rebuilding everything. That's where I am at, I'm tired and frustrated of hearing it.

[01clj]

How many miles are on your truck at 250,000 I had the same problem and ended up replacing the rear end and it went away. I had alot of play in the rear end one way to check it is to drop the driveshaft with rear tires on the ground and turn the yoke going into the rear end and see how much slop is in the gears. I am not sure how much is normal but my old rear end would turn about a 1/3 of a turn or little more back and forth before the gears would catch so I decided to get one from the junk yard and put it in and that solved the problem.

[Bersaglieri]

First let me say forgive me for my terminology I'm new to Powerstrokes and Fords, so please correct me if necessary. However I am not new to fixing broken stuff, so I'm willing to learn.

I'm having a very similar problem in my girlfriend's truck. It feels like some kind of driveline vibration. I'd say the best way to describe it is like driving on rumble strips, but only with enough throttle to sustain a speed over 40mph. Let off the throttle, coast, or go wide open it's not as bad, give it "sustain speed" throttle and it's horrible. Put it in neutral at speed and it's not as bad. Free revving the motor at speed in neutral does not affect it. It almost has a binding feeling. I pulled the front driveshaft as well to eliminate some factors, but it did nothing.

I checked and changed the diff fluid and found some gear glitter and a few small nail clipping size shavings. Very thin. Not sure if that's enough to be alarmed about but I figured I'd note that. From my research her 03 F350 SRW has the sterling 10.5", correct? I'll post pictures of my findings.

Today I'm going to check the fluid in the transfer case, I just rebuilt 2 transfer cases in my Dodge, so pulling and rebuilding another one won't bother me. Putting it in 4HI yielded the same vibration, 4L0 I got nothing, but didn't go over 40mph in 4LO.

I was also thinking TCC [torque converter clutch] maybe a possibility, does anyone know how to force lock or unlock of the TCC to eliminate that as well? On dodges we just ground a wire in the PCM.

I also noticed the 7.3L "injection clicking" stops when you let off the throttle, but it starts again to sustain speed. Could that have any affect on the vibration? I'm wanting to rule this out since in neutral and free revs the problem isn't as bad. Not sure if the motor being put under load could change anything.

I'm committed to figuring this out, so let's start knocking down the possibilities.

Any guides to sterling rear ends on here?

-Dustin-

[ToMang07]

My rig us pretty much doing the same thing... I'm replacing my U-Joints in the rear drive shafts this weekend.... 3 of them with grease fittings is $55 from NAPA. Gonna lube the slip joint, too.

[Bersaglieri]

Found the drivers side auto-hub will not disengage, looks like that could be the problem. Check your hubs fellas.

-Dustin-