vibration problem

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Yeah I'm going to rebalance the shaft before i do anything else here. ...
I did try like 10 different Dodge chrsyler Plymouth vehicles looking for the same drum at autozone. ..non that were the same size :/ 11" id.
My Jeep just started a different vibe this week too, must have caught the virus from sitting next to the Duster lol. Its dif though, not in drive line : doesn't vibe in neutral while rolling or sitting, or park either. ..but, if I'm going down the road and give it gas it vibes through tthe floor and seats, not the steering wheel. So I know its not driveline rolling, just balanced wheels too. Its not motor or mounts either. ..trans is my next point of interest. ..torque converter, flex plate, or transfer case????

Any progress on the "original " vibe issues for this thread???
 
Angle issue ....sounds very probable, thanks super shaft. Especially since I have a 4 inch dick cepick lift on it, how would I remedy that? Either change the d-shaft length or change degree index on the axels????
 
MoPowAR said:
Angle issue ....sounds very probable, thanks super shaft. Especially since I have a 4 inch dick cepick lift on it, how would I remedy that? Either change the d-shaft length or change degree index on the axels????
Click to expand...
i had the same problem with my xj cherokee after i installed a 6 inch lift. a 1 1/2 inch transfer case drop kit and rear axle pinion degree shims cure it . now my duster, still working on it lol
 
MoPowAR said:
Angle issue ....sounds very probable, thanks super shaft. Especially since I have a 4 inch dick cepick lift on it, how would I remedy that? Either change the d-shaft length or change degree index on the axels????
Click to expand...


Lengthening the shaft isn't gonna cure it...

You need to check the angle at the shaft and then the pinion angle at the end yoke...
Is this a link jeep or a leaf jeep
 
73AbodEE said:
i had the same problem with my xj cherokee after i installed a 6 inch lift. a 1 1/2 inch transfer case drop kit and rear axle pinion degree shims cure it . now my duster, still working on it lol
Click to expand...



You need to get a cv slip yoke and have the shaft modified for a cv head, then you want the diff to be 3 degrees lower than the shafts angle.
Dropping the case makes the front shafts bad angle even worse. . .
 
Supershafts said:
Lengthening the shaft isn't gonna cure it...

You need to check the angle at the shaft and then the pinion angle at the end yoke...
Is this a link jeep or a leaf jeep
Click to expand...

Ok, yeah i was starting to try and calculate the size shims to put in from that. .. it has a four link front and a leaf rear. ...
 
T-case has the stub sticking out of the t-case or the normal style t-case? Try and point the pinion at the rear shaft , not directly in line but keep the pinion a few degrees below the shafts angle and should be much better with that issue.
 
Sooo, I ended up putting 3 degree shims in the jeep as well as new U-bolts and motor mounts. she is completely vibe free!!!

Can't say the same for the duster though. I balanced the wheels, checked out the undercarriage (nothing loose), the bearing on the input yolk for the diff feels excellent, wheel bearings look good, jacked the rear end up and put her in drive (no run out in the wheels, straight axle), new u-joints and balanced and straightened the drive shaft, d-shaft angle at the diff looks perfect, out-put bearing on the tail shaft of the tranny feels tight and good, motor and tranny mounts are new....

Vibration hits about 50mph, i can feel it in my seat and the floorboards, not the steering wheel, doesn't go away when i throw it in neutral at speed, doesn't vibe in neutral or park while revving. after i hit that speed it only gets worse the faster i go. if i let off the throttle it doesn't get better, until the car slows below that speed again.

It has a very low pitched, constant oscillation to it (humm, HUMMM, humm, HUMM...) gets quiet and then louder, more violent then it calms. at about 50mph im taching around 3200rpm, gears are 488's..... i think i can faintly hear the same osculation sound at lower speeds but not sure.

Any thoughts??? I'm kinda outta ideas of places to look. My next thought was that the gears were toppin out in the rear end or something was on its way out back there???
Any info or progress on the original or other vibes in this thread???
 
trudysduster said:
I have a 76 Duster I bought 10 years ago and it had a 225/904 combo with a junk rearend. I built a 440 and put a 727 tranny in it and had Moser Engineering fix up a 8.75 rearend for it. I put a set of 3:55 gears andit all seemed ok. I decided to restore it and every nut and bolt came out of the car, dipped repainted the whole ball of wax. Put the same engine back in, same tranny and same rearend. I decided to go with a 4:10 gear. got the car back together,painted , and now I have a vibration that seems to be in the driveline. I thought it may be u-joints so I took the driveshaft to the driveline place and told them to replace the u-joints and balance the shaft. He told me the driveshaft was too short by looking at where the boot rubbed on the shaft. Measured it and lengthened it 3 inches. Put it back in and still a vibration. Thought something may be in the rears so I switched rears and put a 3:91 punkin in it. Still vibrates. Could something have happened in the tailshaft by running a too short driveshaft or in the tranny itself. The tranny runs perfect and shifts so smooth. Am I missing something. About to pull what little bit of hair I have left out. Any help will be appreciated. Maybe someone else has had this. Bill
Click to expand...

3 inches? maybe the trans tailshaft is bent is the problem, along with rear bearings?
 
MoPowAR said:
Sooo, I ended up putting 3 degree shims in the jeep as well as new U-bolts and motor mounts. she is completely vibe free!!!

Can't say the same for the duster though. I balanced the wheels, checked out the undercarriage (nothing loose), the bearing on the input yolk for the diff feels excellent, wheel bearings look good, jacked the rear end up and put her in drive (no run out in the wheels, straight axle), new u-joints and balanced and straightened the drive shaft, d-shaft angle at the diff looks perfect, out-put bearing on the tail shaft of the tranny feels tight and good, motor and tranny mounts are new....

Vibration hits about 50mph, i can feel it in my seat and the floorboards, not the steering wheel, doesn't go away when i throw it in neutral at speed, doesn't vibe in neutral or park while revving. after i hit that speed it only gets worse the faster i go. if i let off the throttle it doesn't get better, until the car slows below that speed again.

It has a very low pitched, constant oscillation to it (humm, HUMMM, humm, HUMM...) gets quiet and then louder, more violent then it calms. at about 50mph im taching around 3200rpm, gears are 488's..... i think i can faintly hear the same osculation sound at lower speeds but not sure.

Any thoughts??? I'm kinda outta ideas of places to look. My next thought was that the gears were toppin out in the rear end or something was on its way out back there???
Any info or progress on the original or other vibes in this thread???
Click to expand...



You said the shaft was straightened. . . .

How off was it, you can only pull a shaft back so far, and on the machine it will look as if it's fixed because it most definitely sounds like it was a dynamic machine (it doesn't spin the shaft at 2500 or 3000 or 4500 or whatever, spins at 500 rpm and guesstimates) and that means the issue is still within the shaft, or the rear yoke is severely worn, but to have that violent a vibration there is a fairly good issue there.

Wish you were in ny id be able to help better.
 
Well I wasn't brave enough to spin the wheels at 50 MPH while sitting on jack stands in the garage...so I don't know if the vibe would continue.

The drive shaft shop said that there was about .040" runout on the front of the shaft. They straightened it by heating it and quenching it with water. They also welded a balance washer to it. I am not sure as to what type of machine they used, ill call and ask.
I did however, notice an improvement in the vibration after. It did not seem as violent. This leads me to believe the shaft is the issue if they didn't get it right. I hate to buy a new shaft unnecessarily though, I'm running low on funds now...
 
-any thoughts on the possibility of the diff causing this type of vibration??? (i dont really know much about these rear ends, never had an issue with a diff before...)
-any opinions on whether or not the d-shaft is still outta wack and causing the issue???

side note; before i buy a new drive shaft im going to see if i can find someone with a "known" good shaft that i can temporarily put in for a quick check. if the vibe finally leaves then it would look like im buying a new shaft...
 
Not the diff, if it was .040 out and they pulled it back to within .010 then they missed something.

If its a dynamic style machine they might wanna try again
 
I have been playing with different shims and the vibration changes so I believe the problem is in the pinion angle. I think when Moser Engineering cut down the axle housing, they welded the perches in the wrong place and the shems arent enough to fix it. I am going to take the housing down, cut the perches, set it back up under the car with new perches and get the right angle and reweld the perches. I am also going to replace the bushing in the tailshaft. Will get back and let you know what I find this spring.
 
If the pinion angle is off you WILL have wicked vibes under powered load or under hard drag load....
If the perches were wrong.... just for arguments sake and you can't get a shim to fix it , you wouldn't be able to drive away from your house without feeling like some idiot dipped your clutch in oil (even with an auto trans it will feel like severe axle wrap), it would be that violent under almost any amount of power.

You originally said you went from 3.55 to 4.10's and THEN you had a vibration.... When that happened it was all in the balancing of the driveshaft which was done for rpms that shaft never seen.
Now with the 4.10's the shaft will see rpms it never would have before....

Just because a shop said it was balanced, and this is my professional factual true experience, some shops don't have a machine and some don't ever use there machine (like its being saved for some special special special moment). I have even spoke with shops and had the idiot owners tell me that balancing is a myth (never use those shops).


Now later on you said the shop then made you a new shaft and lengthened it 3" and you still have the same vibration or did something with that vibration change ? (be specific and detailed i can not drive your car from L.I. NY)


.
 
I had the same problem. Its Torque Converter Shudder. Go to this site try the stuff to see if its what you have.

http://www.agcoauto.com/content/plugins/p2_news/printarticle.php?p2_articleid=203

What is Torque Converter Shudder?

Driving about 45 MPH there is a sudden shutter in the vehicle. It almost feels like running over a rough spot in the road or cattle guard. As quick as it appeared, it is gone, until the next time it occurs.

Such a symptom is often a torque converter shudder. A torque converter shudder is a brief shake or shudder in the vehicle when the torque converter goes to “lock up.” Very often this problem is mis-diagnosed and sometimes transmissions are needlessly rebuilt as a result.

One way to identify a torque converter shudder is lightly touching the brake pedal, while carefully maintaining vehicle speed with the other foot. If the shudder immediately stops, with brake application, the problem is likely the torque converter clutch. When brake application is seen most torque converter clutches will be released. A trained transmission service technician can also test for torque converter lockup using a vehicle scan tool, specific for the application.
 
trudysduster said:
I have been playing with different shims and the vibration changes so I believe the problem is in the pinion angle. I think when Moser Engineering cut down the axle housing, they welded the perches in the wrong place and the shems arent enough to fix it. I am going to take the housing down, cut the perches, set it back up under the car with new perches and get the right angle and reweld the perches. I am also going to replace the bushing in the tailshaft. Will get back and let you know what I find this spring.
Click to expand...

Before you do all of this, check the U-joints. Make sure caps are set properly on the cross and make sure the cross is centered in the yokes on the drive shaft, tail shaft, and on the pinion in the differential. If these things aren't right, no amount of fiddling with the pinion angle is going to make it right. Good luck
 
brkooduh66 said:
I had the same problem. Its Torque Converter Shudder. Go to this site try the stuff to see if its what you have.

http://www.agcoauto.com/content/plugins/p2_news/printarticle.php?p2_articleid=203

What is Torque Converter Shudder?

Driving about 45 MPH there is a sudden shutter in the vehicle. It almost feels like running over a rough spot in the road or cattle guard. As quick as it appeared, it is gone, until the next time it occurs.

Such a symptom is often a torque converter shudder. A torque converter shudder is a brief shake or shudder in the vehicle when the torque converter goes to “lock up.” Very often this problem is mis-diagnosed and sometimes transmissions are needlessly rebuilt as a result.

One way to identify a torque converter shudder is lightly touching the brake pedal, while carefully maintaining vehicle speed with the other foot. If the shudder immediately stops, with brake application, the problem is likely the torque converter clutch. When brake application is seen most torque converter clutches will be released. A trained transmission service technician can also test for torque converter lockup using a vehicle scan tool, specific for the application.
Click to expand...


a 76 duster with a lock up converter.

It's not lock up tc issues.

. lets see how the questions i asked go
 
i have a 67 dart that had a 273 and a 904 trans in it but i got a 74 318 motor and put in front of the 67 904 and ever since iv had a bad vibration in it at any rpm. Would there be a difference with the years?
 
That sounds like you needed the tc for the 18, you missed the internally balanced 18 by a year and that is why you have vibrations, you went from a IB 73 to a EB 18
 
Thanks a lot. Ive been trying to figure that out for awhile now.



Supershafts said:
That sounds like you needed the tc for the 18, you missed the internally balanced 18 by a year and that is why you have vibrations, you went from a IB 73 to a EB 18
Click to expand...
 
Just a thought. It's kinda out there, but hey it's cheap, easy quick,and painless. You didn't squirt any of that tire goo in one of them to stop a leak, did you?
 
MrHemi said:
i have a 67 dart that had a 273 and a 904 trans in it but i got a 74 318 motor and put in front of the 67 904 and ever since iv had a bad vibration in it at any rpm. Would there be a difference with the years?
Click to expand...
Could be....Unless you installed the reducer bushing in the end of the crank for the small button converter, it might not be centered when you bolted it down.
 
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