Driveshaft vibrations

[2001ExpSport]

I have taken my truck to the local Ford dealer to try to fix a vibration somewhere in the drivetrain. The dealer says it might be the U-joints, but refused to repair it because of the WP shackles and torsion twist. I removed the shackles and lowered the tbars and returned to the dealer. He then said it was a characteristic of the '01 exlporer because they drove a new '01 and it had the same vibration. With the shackles off and the tbars lowered to stock height the vibration isn't as noticeable if at all. With the shackles and twist it is more noticeable.

Because the dealer has washed his hands of the problem it seems that I have to find a fix myself. I know that changing the angle of the driveshaft is causing the problem and some how is being transfered through the frame to the steering wheel where I feel it. The vibration happens while accellerating through 20 and then at about 75-80. It only vibrates when accellerating, coasting and breaking causes no vibrations.

Here's my question: Is there a fix for this? New, better U-joints? Re-welding the spring perch to get the correct driveshaft angle?

The other thing is that I don't know if it is vibrating at the pumpkin or the tranny.

I'm not going to leave off the shackels and twist, so for now I have to deal. Any thoughts on this guys?

 

[riffman]

New, better U-joints? - Matt, if it is indeed your u-joints, then heres somthing you can try. With the truck in park, crawl under there, and grab ahold of the drive shaft. Turn it back and forth by hand, and look at the u-joint toward the t-case. If there is an over abundence of play, then its time to replace the one at the t-case. then put on the parking break, and put it in nuetral. Move the drive shaft the same way, and if there is a lot of play there too, then you have some looseness at the axle. If not, then i don't know.

Re-welding the spring perch to get the correct driveshaft angle? - if you're gonna re-weld the spring perch, you might as well go all out and do the spring over. And i would have a shop do the measuring of the pinion angles. Or at least not me!! haha...but if you do do it yourself, remember that you need the angle from the t-case and the angle from the axle to be the same.

talk to our good friend kampy...he'll probably shoot you some good ideas, rather than mine....lol

[Edited by riffman on 01-11-2001 at 09:14 PM]

 

[MOTO MIKE]

First, take your truck in and make sure it's not an out of balance tire(s). after you check the U-joints(and being a 2001 I doubt you'll find them bad) look for a good drive shaft shop, have the drive shaft(s)checked for balance as well. Usually when a U-joint is bad, the vibration is constant. Your vibration seems harmonic in nature and I would bet that something is out of balance. Sometimes a counter wieght gets thrown off. just my thoughts.

 

[DOGMAN]

Riffman delivers the straight skinny. I'd recommend what he did.

With such a new vehicle, it would seem that the u-joints would be an unlikely culprit, unless you've contaminated them with water or mud, or both.

The Sport is shorter than the four door, hence it has a shorter rear driveshaft. With the same amount of lift on a 2dr and 4dr, the 2dr driveshaft angle is going to be more severe than the 4dr. So there is more chance for a vibration.

I'd have the pinion and transfer case angles checked. I'm not positive, but I believe they should be within 2 or 3 degrees of each other.

I'm assuming you have about 1.5 to 3 inches of lift with the shackles and twist. I would think that your driveshaft should still be long enough to handle this, meaning you should have enough spline length engagement in the slipshaft. If not, that causes the driveshaft to wobble, which could be a cause. But usually that only happens when you go with more lift, like 4"-6".

Check everything out and let us know.

[Edited by DOGMAN on 01-14-2001 at 12:32 PM]

 

[riffman]

he he he.....see i got somthing on you guys....i actually wheel with this character here in illinois. You should see some of the SH*T he does!!! hell...it makes me pucker just watching him!! ha! Dead Link Removed

 

[RFR2212]

Um, I've got a sport....With 6 inches of lift....my drive shafts are fine...I see no reason why your u-joints would be bad with no more than 3in of lift...Strange ford crap...
Pete

 

[RFR2212]

Riff--Stop harassing me! I'm scared....AHHHHHHHHH
Pete
P.S. No one worry, Scott is a nice guy, he likes helping people on the lil yellow bus...I believe Matt knows this as well. (Our light rivalry)

[Edited by RFR2212 on 01-11-2001 at 11:00 PM]

 

[riffman]

your nuts pete... Dead Link Removed

-edit portion-
ok...hows this?

Pete, your nuts! ha!

[Edited by riffman on 01-11-2001 at 11:14 PM]

 

[RFR2212]

Scott, please rephrase that. What you said is politically incorrect and some may be offended by that. I sure am.

-UPDATE-
I give up on Scott. It's people like you that create problems

Pete

[Edited by RFR2212 on 01-11-2001 at 11:16 PM]

 

[2001ExpSport]

Well, Ford is out of the loop for sure and I am done dealing with them.

I'll check the driveline next week when I install the body lift. Thanks for the help guys and I'll keep you posted.

Scott, remember the thread about my rear end being off center an inch? I went to the dealer and looked at one in the show room. It's also one inch ****ed to the pass side. Is this what they call new age engineering?

I would give anything for a nice Bronco suspension. Sheesh.

 

[Kampy]

Matt, I'd pull the shaft and have it checked for balance, it's very possible you ripped a balance weight off or dented the shaft on one of our "Explorations".

 

[2001ExpSport]

Could be, but when I took off the shackles to put it back to stock it almost went away completely. When I put the shackles back on, it vibrates again.

 

[MOTO MIKE]

I checked with my drive shaft guy about this problem....we both are assuming this X is driven hard.....he said that it is likely that you may have a bent drive shaft, when you changed the angle of the shaft it amplifies the vibrations because with a bent shaft your U-joint angles are no longer in sync, and the vibrations will lessen with less sharper U-joint angles... just wanted to pass this on so you had another Idea to sort through. Either way,you should probably have your shaft checked just to rule it out as a possible sorce of the vibrations.

 

[2001ExpSport]

Sounds like a good plan. When I get some time I'll take it it and have the shaft and joints inspected by a pro. I won't be able to find anything if I try to inspect it myself.

Thanks for the input guys.

 

[MOTO MIKE]

It's always a good plan to atleast rule the shaft out as a problem, if it's in question at all, any damage to it could mean more expensive repairs down the road, like the pinion or transfer case out put shaft, they should also check to see if it was twisted during one of your offroad trips. Do let us know what they find wrong with it, I'd be interested to see what happened.

 

[felsmann]

Your problem may be the CV axles!

You mentioned that your vibration was ONLY when accelerating, this is typical of CV axle failure, but this should only happen if the 4 WD is engaged. Are the 2001 4WD auto? Some times the computer fails (it happens to me) and it wont dissengage 4WD, even in Auto.

Just a thought...