Post accident vibration

[Hawgman]

Ok, so I fucked up the car a month or so ago. Long story short the road fell out from under me (literally). Car ended up in a sink hole full of water. It went in at about a 20 degree angle about to the middle of the doors. The road was dirt, so no hard or rigid surface leading in to the hole.

Got it pulled out, got the water sucked out of it, fired it up (which shocked the hell out of me) and drove it 300+ miles back home. On the way home I notice it has a vicious vibration that starts around 60mph. Gets worse as speed increases, and even worse on decel. Goes away around 58 on decel. Car was NOT pulled out by the rear end or axles. Was pulled out by the rear sway bar.

Took it to Ford (because it is an insurance job, and I know the service manager there, and it is a mod friendly dealer). Got it on a lift and start looking around under the car. You can see very clearly where the road ended (so to speak). Maybe about at the front of the trans pan or so.

Got all the interior replaced, seat motors and wiring, seat air bags, throttle pedal, SRS control boxes, SJB, and ABS control system. That is probably a little over board but wanted to replace anything electrical that might have gotton wet. Now chasing the vibration.

• Pulled all 4 wheels and checked balance and for a bent wheel.
• Driveshaft does not look like it even got wet, much less bent or touched in any way. Exhaust hangs lower than the driveshaft and it isn't even bent.
• Nothing bent as far as transmission mounts. Hell, they are cast so they wouldn't bend anyway, they would break.
• Trans pan is free of any scrapes or bends.
• Changed engine and transmission fluids. No contamination found.
• Pulled the rock cover off the front of the transmission, nothing up inside there.
• Checked the pinion angle, still at -2 which is where it has been for quite a while.
• Sub-frame, cross member, and motor mounts all check out fine.

One thing to note. While on the lift, noticed a puddle of fluid sitting in the left rear wheel. Looked as though it was coming from the axle seal. So the seal was replaced also. Initial thought was either mud impacted between the disc and the seal causing the leak, or the leak maybe caused by the 300+ mile drive home and vibration.

Car still vibrates BAD starting around 60mph. Put the car in neutral while at speed and the vibration is still there. The vibration does not seem to be RPM related as we have ran it up to higher RPM in lower gears at a lower speed and no vibration.

Pulled the single piece aluminum driveshaft out and put in the stock driveshaft. This seems to have changed the symptom. Now it starts the vibration earlier, and appears to decrease at around 70mph. Actually the exact quote from the service manager was "it goes away at 70". But since I was not there when they tested it, I will not be so bold as to say it actually goes away.

So they hook their EVA machine up to it and take it out for a drive and all it tells them is that it is drive line related (engine, trans, driveshaft, rear end).
Well, you can run the friggin thing up to 6k RPM in first and the vibration doesn't happen. They did say that me having two different wheel sizes jacks with their EVA machine so they are going to pull a set of 17s off of another car on the lot and put them on the rear in place of my 18s and drive it again.

They are now saying they think it is a transmission issue. I just ain't sold on that yet. Plus the fact that my insurance company certainly isn't going to be too hip to the idea of pulling the trans and sending it up to Level 10 to be repaired! To me, if it were transmission related it would have to be one of two things. Either the input shaft or the output shaft got tweaked somehow. If it were input shaft related, I would think that RPM would play in to the picture and it would do it at "X" RPM regardless of the vehicle speed. And since it does it at speed in neutral at 1k RPM, in my mind that rules that out. There is no evidence what so ever of anything that would have caused the output shaft to be tweaked. Also, I think if it were output shaft related, and as bad as the vibration is, that the rear seal would be leaking by now (just my opinion).

So... what the hell.... Any ideas?

 

[hammeron]

it looks like pretty much everything has
been looked at, as a cause for the
vibration, but i can't help wonder if pulling
it out with the sway bar, affected something.

good luck hawgman, i do hope the issue is
resolved soon.

Was pulled out by the rear sway bar.

 

[Freaknazty]

just a wild idea/guess maybe something to do with the rotors/brake setup i know the wheels d/s ect. checked out ok so thats the only other thing that i could think that would cause a vibe but not being rpm related ...hell i dunno hawg

 

[KIM_05_GT]

just a wild idea/guess maybe something to do with the rotors/brake setup i know the wheels d/s ect. checked out ok so thats the only other thing that i could think that would cause a vibe but not being rpm related ...hell i dunno hawg

Thats what I was thinking...When you hit the water it could have possibly warped a rotor.

 

[Hawgman]

Tell ya, at this point I would go for just about any idea. But two things come to mind with the brake setup. First, I was only doing about 10mph when I hit the water so it wouldn't be a force impact related thing. Second, if it were the brakes I think it would be felt at all speeds, or at least show up on the EVA if not felt.

As for the rear sway bar being outta whack. That is possible as well. Easy enough to drop the links and see if it makes any difference. But again, I would think it would be felt at all speeds and just get increasingly worse, not be non existent until a certain speed.

 

[stkjock]

Hawg, do they have a roller set up there? (not necessarily dyno, but even for emissions) that they could get the car on the rollers and see if @ 60 on the rollers that the vibration is there? IMO if it is not there then that would eliminate the drive train and suggest its in the front end. The front end is the most logical as that was what got hit (so to speak)

 

[Dex]

bent tie rod?

 

[rojizostang]

with the leaking rear end seal...could this be evidence that perhaps you have a bent rear axle? I know it doesn't really explain however the vibe going away with the stock ds above 70mph

 

[rojizostang]

can you put the car on jack stands and run it through the gears and look at what the rear wheels are doing? or have you already done that?

 

[Steedman07]

Im going to guess something in the rear end..Good luck..The dealership your working with sounds like good people, they will find it..

 

[2kanchoo]

Hawg, do they have a roller set up there? (not necessarily dyno, but even for emissions) that they could get the car on the rollers and see if @ 60 on the rollers that the vibration is there? IMO if it is not there then that would eliminate the drive train and suggest its in the front end. The front end is the most logical as that was what got hit (so to speak)

This would be what I'd suggest so the car's suspension is under full load while you do it. This way you can walk around the car and hear it out as well.

 

[Hawgman]

Hawg, do they have a roller set up there? (not necessarily dyno, but even for emissions) that they could get the car on the rollers and see if @ 60 on the rollers that the vibration is there? IMO if it is not there then that would eliminate the drive train and suggest its in the front end. The front end is the most logical as that was what got hit (so to speak)

I agree. Only thing is their emissions roller apparently won't handle that high of speed. I suggested the very same thing a couple of weeks ago.

bent tie rod?

Back to that it just magically appears at a very specific speed and magically disappears below that speed. Think a bent tie rod would be felt constantly. Plus, it drives straight as an arrow with no steering wheel wobble. Even while the vibration is happening.

with the leaking rear end seal...could this be evidence that perhaps you have a bent rear axle? I know it doesn't really explain however the vibe going away with the stock ds above 70mph

I am trying my best to push them to investigating the rear end further.
But, the other side of that coin is.. This was an extremely low speed accident, the rear end actually lifted up, did not bounce, was no torque shock to it, and stayed that way until it was pulled out. And as stated above, it was not pulled out by the rear axle or rear end. Plus I have axle braces on it. If it bent an axle, I would be real surprised.

can you put the car on jack stands and run it through the gears and look at what the rear wheels are doing? or have you already done that?

It's been up on a lift and been ran up to "the magical speed" and not a damn thing was seen moving, wobbling, weaving, swaying, or any other word that I can't come up with at the moment.

Im going to guess something in the rear end..Good luck..The dealership your working with sounds like good people, they will find it..

Well.. they are good people, but I am kinda starting to question their diagnostic abilities . They have had the friggin thing for 5 or 6 weeks now, and about 3/4 of the stuff that they have done to try to eliminate things they did because I suggested it.

This would be what I'd suggest so the car's suspension is under full load while you do it. This way you can walk around the car and hear it out as well.

See my comments above about the rollers. I have considered just going and getting the damn thing and cashing out, then taking it to the performance shop I usually go to and putting in on their dyno. But again, I really don't think it is a front suspension issue.

Honestly, I think it is the friggin drive shaft, and I think that when they put the stock drive shaft in for testing they left the pinion angle set at what I had it set to for launching even though I specifically suggested prior then asked after if they set it to zero.

 

[Dex]

turn off your vibrator

 

[Hawgman]

Hell, I even took the batteries out of it!!

 

[94tbird]

when you had the rear end in the air and ran it up to speed, did it vibrate then? If not then its in the suspension

 

[Dex]

when you had the rear end in the air and ran it up to speed, did it vibrate then?

Perv

 

[Hawgman]

when you had the rear end in the air and ran it up to speed, did it vibrate then?

They said it did. I was not there so I cannot state 100% yes or no. Just taking their word on it

 

[Hawgman]

Well, just got off the phone with the Ford dealer. Still no progress. They said there is no way their rollers would run up to 60mph, that it was a POS. They also changed their story and said they didn't take it up to speed when it was off the ground. So I suggested two things. First, try taking it up to speed with it off the ground and see if they can see anything. Second, to completely eliminate the transmission being the issue, drop the drive shaft out of the car, set it back on the ground (or do it in the air, whichever they felt most comfortable with), fire it up, put it in gear, let it run through the gears, and take it up to speed. If it doesn't do anything then that would definitely rule the transmission out and put it back on the driveshaft or the rear end.


On a side note. I bought this transmission from someone who bought it and never used it. He bought it from "a guy" that he knows that had Level 10 build it for his race car, then decided to go with a TH400. So while I was on the phone today with Level 10, they asked me the origins of the transmission for whatever reason. I got in touch with the guy I bought it from, he said he would pass my info along to "the guy" he got it from and have him call me. Got a call from "the guy" a little while ago. Turns out, "the guy" was Vinny Barber! My transmission is the original transmission that was going to go in to his car. Now that I have found that out, I am SERIOUSLY questioning it being a bent output shaft. I somehow doubt that they built him a weak transmission.

 

[stkjock]

wow that's a funny side note

 

[ZmanM3]

I'm guessing that the D/S is hollow? I ask because if mud were to somehow get into it you could get a vibe at different speeds. I'm also wondering if a Bushing may have gotten cracked or torn somewhere in the suspension as to me the fact that you can put it in N and still have the vibe at speed makes me kind of think it is a suspension or wheel problem.