I highjacked another thread yesterday but didn't get many responses so I thought I would start a new one... I've done some searching here but no one had any real answers or had a different reason for the vibration...

We have a stock '05 F150 with 24k mi that is having Vibrations not related to bad tires or a bad trailer. It rattles any cups or change that is in the center console area and the dashboard. It seems to come up through the floor.

Symptoms timeline:

The rear pops when you turn tight in a parking lot. I've been told this is normal because of the ratcheting LSD? Is this true?

The tranny fluid was low and we could not find where it was going. Put several qts in it and finally took it to the dealer where they replaced the bad seal between the transmission and transfer case. So we know they took the driveshaft out and the transfer case. Not sure if they dropped the transmission out.

We have a vibration from about 40mph-55mph under medium-full throttle. A lot worse when towing. Put it in neutral and it goes away. Rev the motor and you don't feel it. Only happens under load. Happens in 3 and 4th gear. Goes away once the torque converter locks up.

Anyone else got similar symptoms? Am I going down the right path in saying it's a bad torque converter?

 

Were you getting the vibration before the dealer changed the seal, and if not how long did it take to come up? I ask because the dealer may have not put something back right or not tightened somthing and it is starting to loosen. Just a quick thought.

 

I agree with fireman. I don't think the dealer installed the driveshaft properly. Normally, we match mount them to reduce any vibration. I would take it back to the dealer and have them re-index the d/s and see if that helps. Look at the rpm range when the vibration occurs. If you can get at the same engine speed in each gear, I 'd say it maybe engine or convertor, if it occurs constantly at the same vehicle speed regardless of gear, then it's probably d/l related.

Either way, it didn't do it before you took it in and now it does.. Dealer missed something..

 

I'm gonna say it again, just like the last time you asked the question. I am certian it is a bad U-joint. The oil loss sounds to be accounted for by the leaky seal that had been replaced. If it was the TC, you would feel it more on take off than any other time. I swear that it's a bad U-joint.

 

I've had trucks with bad U Joints and out of balance driveshafts and this doesn't have the harmonics like that at "certain speeds". It's like it only makes the vibration when the TC is working really hard and when it's crusing locked up it doesn't no matter what speed ur going. The dealer's "transmission guy" can't look at it til Monday.

 

If it goes away when you put it in neutral then it's not the driveline or u-joints as those are still spinning at speed and you'd still feel it if it was them. It's something in the tranny/transfercase I'd bet dollars to donuts.

 

I have had U-joints only act up under load due to the torque on the driveline. Take your foot off the gas or throw the transmission into neutral and you release the torque from the drive line allowing the U-joint to go slack and run true.

Heres a quick way to check. Park on a flat surface. Block the tires and place the vehicle in neutral. Crawl under the truck and shake the drive shafts side to side then up and down to see if there is any play. Any lateral movement in any direction would confirm that you have a bad u-joint.

If it was the TC, you should feel something like a churning vibration. Have you check the oil and does it smell burned?

 

It ran low on oil for a long time I'm afraid before my dad noticed. Only reason he checked the fluid was because it wasn't shifting right anymore and I went and put 2 or 3 qts in. It kept leaking more and more into the transfer case and not on the ground so we put another 2 qts in before finally taking it to the dealer to get it checked out and they found the leaky seal. The transmission fluid is fairly new now and doesn't smell or look bad at all.

Would putting the truck in 4WD (going straight ahead on pavement) and making a run check the U-Joints? I've done that on older trucks that were suspect. This truck only has 24,000 miles so I kinda ruled that out to begin with.

It is a reverberating vibration which goes away once the transmission locks up.

We'll see what the dealer says on Monday, I hope it will be covered under warranty. If not then it's going to a transmission shop to be repaired.

 

They could argue that you voided the warranty on the transmission because the oil levels were not checked regularly?? You may want to argue that it was the defective seal (covered under warranty) that caused the premature failure of the TC and had the seal not been an issue, checking the trans oil at regular intervals would have been sufficient.

Good luck.

 

The dealer's "transmission guy" rode with me Monday and it was a first for him. He ran his scanner locking and unlocking the TC and got the same results I have known.

They called Tuesday and said that the vibration was coming from two tires that were bad on the left side.

Wednesday afternoon we called and they said it was "ready". Ford absorbed the cost of one tire, the diagnostic fee and we had to pay for one tire plus the mounting and balancing that came to $209. I talked with the "transmission guy" when I picked it up. He said he rotated the driveshaft 180 degrees and updated the programming on the computer. They "road balanced" the tires with their $15,000 machine and he said the vibration was "better".

I drove it out of the parking lot and as soon as I was able to get it up to 50+mph the vibration came back again. I am sooooo pissed. I called the service manager immediately and he was unavailable for the call but still in the building because I called the main desk and the secretary said he was still there. I had to go to an appointment at 7pm so I didn't have time to waste with him and we will see if he calls back tomorrow.

 

geez, i'd be pissed too! wish u luck man! you might have to whoop some *** man!

 

By the sounds of things, even the transmission guy was not convinced that it was the TC. By rotating the drive line 180 degrees and repairing the faulty tires, he may have just put you back at square one. I would ask if they did a road check with the replaced tires before they spun the drive shaft. If not then I would demand that they immediately get your truck in return the drive shaft to its original orientation, road check (with the tech or service manager) and if the vibration still persists, demand your money back. The placement of the tires was their choice of diagnostic method. Since their diagnosis did not result in a positive outcome, it should be their cost to bare not yours. They are milking you a little at a time and before you know it you are into them for 3K for normal wear and tear items. Maybe you should at least ask them to take you out to dinner first. Unless you not that kinda guy......thenI would suggest the following.

If at all possible try and stay there while the repair is being done. Strike up conversations with other people on the sales floor or in the service lounge area (just outta earshot from the service manager but so he can still see you) and start telling stories flapping your arms and pointing toward the service desk, it doesn't even have to be about them but they will certainly do what they can to get you outta there as soon as possible and repair the issue so you don't need to return.

Here's another question, why are the two tires on the left side wearing more than the right. Are you driving the oval track to work every day? Do you rotate them in a front to rear cross pattern?

 

I know it has been quite some time but does anyone know what the outcome was with the vibration issue?

 

Still vibrating in 2nd and 3rd gear mostly and up until torque converter locks up... Have 4 different brand tires on the truck now and it's just as bad... Not u-joints as it will vibrate at 35-45mph with converter unlocked and not vibrate at same speed if it is locked up.

 

I just had a transmission rebuilt and now I have a vibration, when I picked it up they said they had to put another TC in as the one they got from their supplier was out of balance, so they put another one in (so they say) and I'm still having a vibration, I'm taking it back Friday for yet a 3rd TC to be installed, I'll let you know how it goes. The vibration was not there until the transmission went out/was rebuilt.