What else could cause a vibration???

I had a similar situation on my first transmission. My problem turned out to be a twisted tailshaft. I have no clue how that happened in my car with as little power as it had, but it def did. I had never heard of anyone doin that other than me, replaced it and the vibration was gone. I didnt diagnose it, i took it to my friends transmission shop. He had many parts laying around from other T-5's and just made me pay labor and a couple of the seals i blew out from driving it like it was. Hope this helps a little bit if any....-Jeff

88Stangboy said:

jack your car up and check where the drive shaft bolts directly to the rear end. Replace the driveshaft bolts. They may be backing out or not tightening all the way. I had the same problem over the summer, changed a couple parts and the vibration was still there. Turned out my bolts wern't going all the way into the rear and it was causing the shaft to be loose and that was my vibration problem. YOur more than likely going to have to go to a junk yard, i went to every Auto zone, napa, Advanced in the land....finally had to go to local junk dealer. Found all 4 for $5

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The factory bolts are threadlocked in place. New bolts from the dealer have threadlock on them as well. Always good to threadlock them in place, or issues like above can occur.

88Stangboy said:

jack your car up and check where the drive shaft bolts directly to the rear end. Replace the driveshaft bolts. They may be backing out or not tightening all the way. I had the same problem over the summer, changed a couple parts and the vibration was still there. Turned out my bolts wern't going all the way into the rear and it was causing the shaft to be loose and that was my vibration problem. YOur more than likely going to have to go to a junk yard, i went to every Auto zone, napa, Advanced in the land....finally had to go to local junk dealer. Found all 4 for $5

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Sorry to hi-jack the thread but I have had that same problem before also. Spapped 2 driveshaft bolts and lost one and no one could get them. Even a few Ford dealers I went to. Snagged them off a junk parts car of a friends. Does anyone know where to get new ones? I don't need any at the time but it would be nice to know if I ever do. Thanks. And sorry again

Does it do it in any gear ?

EDIT:Never mind, just reread the original post

www.50resto.com search HDW-4602

Here is something I haven't seen anyone post; have any of you with the vibration mentioned checked your pinion angle. Mine vibration, has changed over time. I started with an alum driveshaft, then I balanced it to be sure both times the vibration got a little better, more like it moved up the mph whcih it started from 70 mph to closer to 80. I have replaced all the parts on the engine that have been mentioned. The next thing I did was the wheel bearings, this was done during a 5 lug swap again it was marginally better. The last thing I tried was a suggestion that goes against what a lot of others have posted on this and other boards about this vibration. That is remove the balancer on the rear axle. I did this and again a marginal gain. So now it doesn't get too bad in the feel of the shifter until 90 mph. Something else I noted is if I shift from 4th to 5th it will start happening without a mph increase. So that's what got me thinking pinion angle. The rear axle is becoming unloaded. However I during the 5 lug I added bushings so this should be a non issue unless the car was assembled out of spec. If this were the case it may be that the axle is just out enought to cause a vibration, and the load twists the axle back into an area where vibration does not occur. If I run 4th gear on up to say 100-110 the vibration is there, but not as bad if I did the same speed in 5th gear. I may be totally off track here, but it's free to check my pinion angle so I guess we'll see.
j

91RRLX said:

................. Something else I noted is if I shift from 4th to 5th it will start happening without a mph increase. .............

......................If I run 4th gear on up to say 100-110 the vibration is there, but not as bad if I did the same speed in 5th gear. I may be totally off track here, but it's free to check my pinion angle so I guess we'll see.
j

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If rpm affects the vibration than I wouldn't bother with the pinion angle myself.
Not ruling it out, but my thought is that at 70mph the driveline rotates at the same speed regardless of which gear the tranny is in.

I would be more inclined to believe a bearing in the row-box is rotten ... or a slightly bent shaft or something internally is not on-the-money ...

My other guess would be engine assembly is slightly out of balance or correlating parts (flywheel, balancer)

Ford has new driveshaft bolts under N-800594-S100 they are 12mm x 1.75 with a 12mm 12pt head.

YMMV, Don

TrunkFunk said:

If rpm affects the vibration than I wouldn't bother with the pinion angle myself.
Not ruling it out, but my thought is that at 70mph the driveline rotates at the same speed regardless of which gear the tranny is in.

I would be more inclined to believe a bearing in the row-box is rotten ... or a slightly bent shaft or something internally is not on-the-money ...

My other guess would be engine assembly is slightly out of balance or correlating parts (flywheel, balancer)

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I can see where you might think my claim is a rpm issue however I don't believe that it is. The only time this vibration happens is at high speed (mph) If i could "cruise" at 110 in third gear it would still happen the way it does when I push it on up to that speed in 4th then cruise there as well as in 5th. I'm not saying the tranny is not bad. I just brought the point that no one has mentioned pinion angle, afterall we have to assume that everything is still in alignment the way ford assembled these cars 15 years ago.

Also if the engine were out of balance this vibration could/should be felt in neutral at 0 mph withe the engine at that rpm, as well as when cruising in any other gear at the rpm of the vibration. But again it is NOT rpm specific. I can get it to happen in different gears over wide rpm ranges.

91RRLX said:

I can see where you might think my claim is a rpm issue however I don't believe that it is. The only time this vibration happens is at high speed (mph) If i could "cruise" at 110 in third gear it would still happen the way it does when I push it on up to that speed in 4th then cruise there as well as in 5th. I'm not saying the tranny is not bad. I just brought the point that no one has mentioned pinion angle, afterall we have to assume that everything is still in alignment the way ford assembled these cars 15 years ago.

Also if the engine were out of balance this vibration could/should be felt in neutral at 0 mph withe the engine at that rpm, as well as when cruising in any other gear at the rpm of the vibration. But again it is NOT rpm specific. I can get it to happen in different gears over wide rpm ranges.

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Gotcha ...
I was under the impression you were saying the vibration would change with an increase in rpm as the mph remained constant ... not that speed changes the vibration so much.

onefstsnake said:

I have the same problem.

At 75-90+mph you can hear and feel the vibration.

Mirrors shake so bad you cant see anything... Shifter vibrates...
I havent replaced any of the things you listed so it might not be the same thing.

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same thing with me.. I have an aluminum driveshaft though..

Just curious. this may or may not have to do with the problem.. but do you happen to hear the sound of a tire rotating very fast when you're driving?.. Can't explain it too well.. Anyway I have the same problem, Hopefully you can get down to it which can help me 2 figure out why I vibrate around 75-9o mph! (sorry my post didn't help Any .. just wanted to put my .02 in...)

I had a nasty vibration in my car with the same symptoms...when i would get up to about 80-85 after the gear swap to 3.73's, no matter what gear i was in a got a nasty vibration through the shifter and it would shake the whole car especially if i got off the gas. I just had the stock driveshaft re-tubed and balanced for short money at a big rig truck shop with new u-joints and that almost fixed the whole thing. However, my shifter still vibrates at speed in fifth gear. I was also thinkin of the slightly bent shaft of some kind, either imput or tailshaft. and maybe that problem developed from the 6,000 miles i put on the car with the old DS and bad vibration??? I also considered the clutch (B/c at that time i had a ****ty autozone stock replacement) But i will have to see how it is with the new Spec clutch this spring. good luck man let us know what works for you?!