BAD driveline problem - please help before Ford tries

[Baddecision93]

Ok...I could really use some help before the Ford garage gets to me. I would like to go in armed with some knowledge if at all possible.

Here's my problem:
A vibration so bad that it renders the truck almost undriveable. I can't take it over 20mph. I can't tell where it's coming from but it makes a "clack clack clack" noise, in forward or reverse. The noise speeds up as I do and it's just as bad in 2WD or 4WD. If I speed up past 10mph the steering pulls left then right, randomly, basically just swerving all over.

The history:
- Everything was working fine, so I decided to mess with it
- Installed 4" Rough Country lift in the front
- Did SOA on the rear
- After SOA I tried to back it out of the garage and got a big clunk. Looked underneath and driveshaft fell out.
Came to discover that my perches were welded at a very incorrect angle and the pinion was pointing down.
- In doing the SOA the driveshaft had been unbolted from the rear differential, so it has been disconnected from both ends at some point during this whole deal.

The attempt to fix it:
- Removed and re-welded spring perches and got a good looking pinion angle
- With the correct angle put the driveshaft back in and have a good amount of spline in the yoke

The confusion:
- After the attempt to fix it, things are still WAAY screwed up. I know it needs an alignment very, very badly. Could it be that all it needs is an alignment?

- With my limited knowledge I can't understand how I would have permanently screwed up my transfer case but could this be the problem?
I know that disconnecting the driveshaft completely without marking reference points can throw off the balance so I've already conceded to the idea of buying a new driveshaft.
Beyond a driveshaft and an alignment I have absolutely no idea what to expect.

I'm kind of thinking those 2 things should fix it but if there's anything else it might be I want to have a good idea before Ford decides to rebuild the dang thing from the ground up just for something to do.

 

[jkkrau]

bad front drive shaft

I had a bad front drive shaft on a 2000 mounty with awd. I will tell you when it went it was like trying to drive a paint shaker down the road. I was doing 15 mph. I thought the truck was going to flip. Removed drive shaft and drove it around, truck was like new until I came home from vacation and put in rebuild unit.

 

[Baddecision93]

I had a bad front drive shaft on a 2000 mounty with awd. I will tell you when it went it was like trying to drive a paint shaker down the road. I was doing 15 mph. I thought the truck was going to flip. Removed drive shaft and drove it around, truck was like new until I came home from vacation and put in rebuild unit.

Well, maybe it's a bad front driveshaft...I can't see why cause I never touched it but I guess in lifting it I did change the angle.
Hopefully Ford can figure it out w/o playing w/a bunch of other stuff.

 

[Baddecision93]

Other ideas?

Anyone else have any clue as to what may be the issue?

Dropped it off at Ford two nights ago, T-minus 2 days till they start fiddling with it...

One more thing I found, don't know if would make that much of a difference, but found my front sway bar bushings laying in a pile of tools...we may have forgot to put them back in. I know a lot of you don't run it at all so I don't know how much that would really affect anything.

So, help/suggestions?

 

[corkey]

might be the driveshaft inside the ttb passenger side front having a bad u joint,,

look between the ttb arms at the shaft and try to wiggle it around,, the angle change of the lift may have amplified the problem of a bad u jnoint in there,

 

[Albino 94LTD]

There's a number of things to look at before going to a shop.

If you lifted the rig 4", you should consider lengthening the drive shafts to make sure you have enough splines engaged in the slip joints. Also check the

For the front, you can use the 'socket' end from a rear drive shaft, it's about 1" longer.

For the rear, you will need to have a shop lengthen and balance.

Your pinion angle should be parallel to the angle of the output shaft of the transfer case. I'll assume you have corrected this?

Another and very important, thing to check is the orientation of the U joints. The ends of the drive shaft need to line up exactly.

As for the steering pulling left/right, try running a string around a rear tire and up to and around the front tire, over to/around the other front tire and to/around the other rear tire. This will help you set the 'toe' so you can get to the alignment sop

 

[Baddecision93]

Thanks guys.

I have a feeling I'm going to be seeing some U-joints in my future...there was a very minimal amount of slop before, but it was there and I know I had to have amplified it with the lift.

In regards to lengthening, it seems like most guys that do a spring-over don't have to. Could it be that I'm just one of the unlucky ones?

We removed and re-welded the spring perches once we realized how far off the pinion angle was and (IMO) the driveshaft now has a sufficient amount of spline in the yoke.

I'm prepared (mentally, at least) to end up dropping $ on Ford's alignment, some extreme angle camber bushings in order for them to do the alignment, and a lengthen/balance of the rear driveshaft.
Guess I hadn't really thought they would have to touch the front since I didn't but I guess any change of geometry can throw things out of whack.

I also understand there may be a need for new u-joints and possibly tie-rods and ball joints (they didn't look the greatest when I inspected them but I figured I'll let Ford be the final judge).

I appreciate the input guys...hopefully I can get away without blowing too much money.

One more thing:
Thankfully had access to a trailer so we just loaded it up and hauled it in to go get the alignment. Didn't want to risk screwing something up driving it 10 miles out of whack. So it's at the shop now, just waiting for them to get to it.

 

[Baddecision93]

Called Ford last night and they're still thinking Friday until they can even look at it.

Anyone wanna weigh in?

I wouldn't have been able to put the splines back in incorrectly, right (like one spline off)? My dad is just sure-fire convinced that's what it is. There doesn't seem to be a "keyed" part of the shaft so I guess maybe in theory I could've put it in wrong?

Anyone else have problems with bad vibration after lift?
It would be epic if someone else had the same problem and it was cured by just a simple alignment.

 

[06bluez]

Is it a one or 2 piece driveshaft? if it's a 2 piece, and the driveshaft halves seperated, it is important to align it so the ujoints are in phase, or you will have the vibration you described.

if its a one piece driveshaft or it didnt come apart, maybe it was damaged or bent when it fell out? porbably will need to take it to a driveshaft shop to inspect it and rebalance it.

 

[Baddecision93]

Is it a one or 2 piece driveshaft? if it's a 2 piece, and the driveshaft halves seperated, it is important to align it so the ujoints are in phase, or you will have the vibration you described.

if its a one piece driveshaft or it didnt come apart, maybe it was damaged or bent when it fell out? porbably will need to take it to a driveshaft shop to inspect it and rebalance it.

It is a one piece...there just a spline on one end that goes into the slip yoke that attaches to the tranny (there is a u-joint on the end of the slip yoke but it stayed attached) and then there is a u-joint on the back end of the drive shaft that attaches to the differential.

I know that you need to mark the u-bolt on the drive shaft to a flange on the diff to get it back to the exact same place (because of balancing issues) but if those are together right I can't slip the splines in wrong, can I?

Either way I hope Ford can figure it out...I'm ok with paying to get my drive shaft rebalanced and even lengthened if need be. I'm ok with new u-joints since they are a maintenance thing anyway...I'm just really hoping there isn't something else wrong.

Ford did mention that maybe it got bent when it fell out. That's always a possibility too. If that's the case I will just try to pick up a new junkyard shaft (and the slip yoke too, from what I understand you need both to come off the same vehicle so that their matched balance goes together).

 

[Baddecision93]

Got my Ex back...felt the need to give the resolution to this problem.

Turns out that correcting my pinion angle was good enough. The vibration was a combo of it being horrendously out of alignment and the pre-load (or load?) on the passenger side wheel bearing was set very incorrectly and they said the whole bearing was actually slanted to one direction. I never touched that so I wonder if it was from test driving it (even just to 15mph) when it was so far out of alignment.

I feel stupid but I'll post this just in case someone ever runs into the same problem. The clacking noise? Definitely long ends on zip strips...When we removed the original metal rings holding the dust cover (boot) over the driveshaft end we just replaced them with zip ties and never cut the ends off. That was all it was.

Total damage wasn't that bad; alignment, brake power bleed, new master cylinder(not sure why that was bad) $321. Not great but I'll take it for Ford rates.