bad vibration

[pigonawing]

82 eagle sx4 ad vibration around 45 and 60 mph i replaced the u joints and still vibrates do i have a bad drive shaft or is it something else?

[GRONK]

Could be a wheel out of round or something as simple as mud in the inner wheel well.  This happens on my Ford Escape all the time.

[Prafeston]

I get a bad dash vibe sometimes. In my case it doesn't appear to be speed dependent. Sometimes I could be running at 80 with no vibes...other times it's shaking like crazy at 60.

[BenM]

If it's at two distinct speeds (Try driving in different gears to check) U-joints are not a bad guess. Is there lots of play in them?

If not, I'd suspect wheel balance or bad tread on a wheel. Does it come from the front or back?

[pigonawing]

changed u joins no change. and it is coming from the rear of the car

[carnuck]

Worn pinion bearings making the driveshaft play crack the whip or worn slipjoint in the driveshaft.

[BenM]

Rotate the tires front to back and see if it changes. If not, I'd suspect the axle bearing.

[shanebo]

The drive shaft can also become out of balance due to a lost balancing weight causing a similar scenario.

[txjeeptx]

Haven't been on the Nest in a while(Shanebo, I haven't forgotten I owe you).

More info on the type of vibration? Speed dependent? Acceleration or braking dependent? Bumpy road dependent?Frequency(humming fast or steady thump)? Harshness(metallic or muffled)? Was it there before the u-joints were replaced, or is it new?

The pinion yoke on older Eagles does not have u-joint locating tabs like the later Eagle and Jeep D35 yokes do. If you got u-joints for the later application, they lack the circle clip that holds the cups in place in the older style yoke. Then thers's nothing but the clamping force of the straps to hold the cups in place, and nothing to center the joint in the yoke, so it will vibrate and eventually come apart, violently. You would know if you got the correct part or not, based upon whether you have the non-locating tab yoke or if the ujoint you bought had the circle clips, or if your Eagle has the later Jeep-stlye yoke with locating tabs. It would be hard to assemble the wrong part and get it centered up on the old style yoke.

If the pinion bearings are worn, the seal will be leaking more than the normal little weep of gear oil that collects crud around the seal - the area will be wet with oil. Also, you would be able to move it around by grabbing the driveshaft and pulling on it.

When you replaced the u-joints, did you possibly take the slip yoke apart(separate the two pieces of the driveshaft)? They might have gotten reassembled out of phase. The two u-joint crosses must be in exactly the same orientation(in phase), or vibration will result. In phase is where both crosses could sit on a flat surface and be in the same orientation, cup for cup. Out of phase, only one joint can sit on a flat surface, while the other one will be angled some other way.

[pigonawing]

k i have the right u joints cause that was a head ache in it self haha. the vibbe was there before and after the u joint change if i shift out of drive to 2nd gear when it starts vibrating it stops and it only seams to vibrate when you hit 45 or 60 and let off the gas and then start to accelerate again if you are accelerating to highway speed its fine it just when u let off the gas and then press down again i have pulled the tranny twice in the last year no vibe after the first time but its there now after the 2nd. the vib is like a muffled hum that shakes the dash and u feel it in the seat it is coming from the rear of the car. reasons for tranny pull 1st time was tranny went out 2nd time was bad front seal. the resr shaft is solid with mo slide and it still has balance weight on it. front shaft has the slide. some reason i just dont think its the tires. im running outta ideas may try and see if midas can diagnose it  im out of ideas.

[83Eagle!]

Only issue with midas is the way you have your exhaust.  They may not like that.  IIRC that was an issue for one of the guys I talked to about your Eagle previously.

[carnuck]

Tcase coupler/carrier bearings headed south? Front driveshaft Ujoints going bad?

[pigonawing]

what are Tcase coupler/carrier bearings. cause im fearing tranny issues again.

[carnuck]

Transfercase (the part behind the trans)

[83Eagle!]

I would hope it isn't tranny issues.