FIXED! - ANOTHER UPDATE - 2001 ST / Harmonic Vibration

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David Ponder

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Ok, I have heard stories about Driveshaft Vibration, and I needs some help. I have what feels like a Driveshaft Vibration starting at about 60 mph and on.. It doesnt feel like a wheel vibration. I replaced the U joints and now it feels like it is worse..



Need some help or direction here... Have to get this fixed ASAP.



Thanks.
 
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Did you rotate the tires to see if the vibration changes?

I had my driveshaft balanced and new u joints installed for $150 locally.
 
Did you mark the flange. Where it bolts to the rear. If not try rebolting it in a different bolt hole.



Also is your shaft the steel or aluminum. The steel is the one with balance problems.
 
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Rebalance the whole drive shaft.......



Todd Z
 
TSB 05-20-11 states to replace a steel driveshaft with an aluminum driveshaft. It does not state the source of the vibration.



I have done a lot of work on mine and spent a bunch of money trying to fix the vibration, but have not.



If your problem truly is as stated in the TSB, I believe it is a vertical plane misalignment.



Good luck.
 
So what year did they change from Steel to Aluminum?



Edit: So I can see about getting one from a Salvage yard
 
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Not sure. The TSB states that it applies to 2001-2005 years, but the TSB was issued in 2005.



If you want to find one in a salvage yard, simply ask. The part number in the TSB for the aluminum driveshaft is: 3L2Z-4602-AB. Bolts: N800594-S100 (fout bolts per package). Ford is proud of these bolts and charge accordingly. If your current bolts are in good shape, just use Loc-tite.
 
I had the same problem. I heard the same answers. It could be so many different things. Save yourself the trouble and take it to a shop. I did it all. New u-joints, alignment, tire balance, I almost rebalanced the driveshaft but I'm glad I didn't. Check your driveshaft first. Check the angle, you can get a angle measurig tool for like $5 at lowes or home depot. Its not the best thing but it works.There should be some weights about the size of a dime on both ends. Mine has 2 on one end and 1 on the other. It could differ from each shaft. But if one is missing you should notice a spot from where it was. Just in case.... Check your transfer case, mine was leaking, and the seal went bad. This went from a bad seal to a bad ball bearing. Replaced all that and my ST runs smooth now. Good luck!
 
Well, I pulled the driveshaft. Took it to a local Driveshaft rebuilder and they said thy had to straighten it and it was off balance. (It does have a weight where there was not one before)



Reinstalled the driveshaft tomight and headed for the highway. The vibration used to start at 58-60 mph, and now it starts about 65 mph... Not gone, but definately still there.. Same vibration, but not as harsh.. 03ST I feel your pain. Taking it to the shop tomorrow I guess... :sad:
 
OK took it to the Dealer and they said the front U-Joint is bad.. I didnt believe them.. I told them I just replaced them AND had the shaft balanced. IF it was bad, then the driveshaft shop would have found that. They insisted and asked if I could come see for myself.. I was at work and couldnt. Told them to replace it, and SAVE the old Ujoint for me.



4 hours later I get a call that they replaced it and the vibration was still there... I was not a happy camper.. The dealership ate the labor for the U-Joint install, and sold me the U-joint at cost as they insist it was bad, but not the cause of my problem. Now they say the Rear end may be the cause. (Nope, I stopped them there, and picked it up) Diagnostic charge and U-Joint was $78.00.



This was Friday evening. Wasnt feeling well either so was on my way to Urgent care (Sinus issue) and gor Rear Ended.. GEESH !!! 21 year old in a 2003 Caddilac CTS. I have a receiver hitch I installed and that plus the receiver itself took the brunt. Punched a 2" hole in his front bumper of his car. On mine, the hitch is pushed in 4" and down 2", Bumper is pushed in 1" on right side too. Got one estimate on Saturday for $1130.00. Guy wants to pay it out of his pocket, but I have all his insurance info if he backs out.. He is active military, (Army) and had all his ID's so the wife and I are going to try and give him a break. Get one more estimate on Monday then he either gives us the cash or I call insurance. (I have full coverage, so they can go after his insurance) Wife was in the truck with me too.



So I re-read above comments and checked the rear seal on the transfer case, Yep, it has been leaking. Pulled the fill plug and got some mercon V and added some. Took a half quart. So, it was low. // It is possible the bearing is bad and THAT caused the seal to start leaking. I am takling it to Transmission shop to have the T-case checked as soon as I can.
 
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Stopped by the local Transmission shop today, explained all that I had done, and the first thing he asked was "Is it 4WD?" when I said yes, he stated it was likely the FRONT drive shaft. (This had not occured to me) He said he has seen several late 90's Early 00"s explorers with bad ujoints or otherwise out of balance front shaft. He even said the replacement shafts he gets, several have been out of balance and he has to replace them again.



Next step, Remove the front shaft, drive it, and see if the vibration is gone.
 
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Front shaft removed, still have the vibration.



Reinstalled front shaft, removed rear shaft, and drove it in 4WD (So front would pull it) vibration gone, smooth as glass.



BIT the bullet and ordered the Aluminum drive shaft from Ford $603 including express shipping. Should have it Tuesday. I looked at DOZENS of salvage yards, NO ONE had an Aluminum one.



I'll let you know what I find. Wish me luck..
 
Ford replaced the steel driveshaft with the aluminum one on my '03 Adrenalin 4x4 for free. There was a TSB for it.
 
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The new aluminum shaft will make it better, but won't fix it. I predict vibration at 75 MPH. You would not believe the list of things I have tried to fix this. Well, maybe Dave will ;)



On mine, there are two things left - vertical plane alignment of transfer case output shaft to rear differential pinion and adding a double caran joint and never deal with it again. In fact, if you had this, it would have cost for a driveline rebuild and the new double joint setup - 300-$400.
 
Gavin, Yes, I know of the TSB. Only applies if under warrany. (Mine is far from it) I tried everything I could think of but am at a loss. The cost of this hurts.. I HOPE it makes it right.



Yardsale, Yes, I DO believe it.. If this doesnt work, I dont know what else to try. The Transmisson shop said the Transfer case bearings were fine, but the seal is leaking slightly. The ST is at stock ride height, so I cant see the angle changing somehow in the last 4 weeks. Transmission shop even installed a used driveshaft, and while the vibration happened at a different speed, it was still there.



When I had the driveshaft out, I noticed a little play in the slip yoke. Not a lot, but slight play. My hope is that THIS is what happened to cause this at such late mileage. (148K miles) and that the new driveshaft will solve the issue. I am supposed to leave Thursday for an 800 mile R/T and may be pulling a trailer back. Going to be a long trip if I have to hold it under 60 mph.
 
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When I note vertical plane alignment of the transfer case output shaft to rear differential pinion, I mean left to right, not up and down, which is the typical concern and what most shops will check. The motor and or transmission mounts can be off to one side, or the rear axel can be shifted, causing the output and input shafts to not be parallel. Two fixes for ths come to mind - find-out what's misaligned and fix that or add that double cordon joint to minimize the angle differences.



Things Ive tried:



Sent the rims to the manufacture for balance tests

Checked the radial and lateral run out on the rims

Tested on blocks and test driving every possible combination of front and rear only driveshafts, 4WD engaged and not, with two sets of wheels (interesting stuff with no driveshafts and 4WD engaged) (Tests and results in the VibrationTests folder of my library.)

Replaced the transfer case rear cover with bearings and seals

Had driveshaft angles checked (3/32 shim needed under transmission mount)

Rebuilt front and read diffs. (re-geared)

Rebuilt both drive shafts, the rear twice both times the shops said that it was pretty good and they recommended changing only the u-joints as a preventative measure.

Replaced the rear drive shaft with the aluminum

I may be forgetting something, or blocking it as to not relive the horror.



Replacing the steel driveshaft with the aluminum did make a difference it raised the speed at which I feel the vibration from about 65 to 77MPH. Thats not a lot of headroom.



While replacing the steel drive shaft with the aluminum did make a difference, I will say that it is NOT a solution unless the driveshaft is defective. That replacement is Fords way of masking the real defect lowering the weight of the driveshaft reduces the rotating mass and raises the speed at which the vibration can be felt. Simple physics.

 
UPDATE .. Installed new Aluminum Driveshaft, & Vibration is 99% gone. Smooth all the way up to 85MPH, then very slight vibration. That vibration may be tires or rotors at that speed. I am happy I can set the cruise at 75 & its smooth.



I took a good hard look at the steel driveshaft, and I really believe the issue is in the slip yoke. The New one is almost as big around as the driveshaft itself, but the steel on is much smaller. Dont know how I would find out, so open to suggestions there.



Thanks to all for the help and well wishes!
 

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