Charger vibrating at highway speed.

[Street fighter]

I have a 73 dodge charger that vibrates at speeds above 50,it's so bad that I believe it may be causing the rear seal to leak trans fluid. I replaced the drive shaft and u-joints but the problem is still there, I believe it may be coming from a worn out rear end. I had the wheels on the rear balanced but it don't seem to help. could the rear wheels being out of balance cause the vibration? I also sense a noise that seems to be coming from under the car also jacked up car and checked rear end but there was no play or no sign of leaking. need help.

 

[bbcharger71]

Do you hear any Whining noise?

 

[Richard Cranium]

I I believe it may be coming from a worn out rear end.

An old worn out rear end will definitely vibrate a lot.

 

[kb67mopar]

Take the driveshaft out and hold a straight edge to it all around its perimiter. I bet your driveshaft is bent. this could happen from hitting something or it could have torqued a bit from being old and weak. I would really suspect its no longer straight.

 

[Big Bad Dad]

Check the driveshaft for out of balance, or bent. Also, a commonly overlooked item is a worn out tailshaft bushing in the transmission. That is the one the front driveshaft yoke rides in at the rear of the tranny. I had it happen to me, and lost a tranny tailshaft housing because of it! :angry1:

 

[Dennis H]

An old worn out rear end will definitely vibrate a lot.

Those are the "Good vibrations" that the Beach Boys sang about.

 

[Big Bad Dad]

Check the driveshaft for out of balance, or bent. Also, a commonly overlooked item is a worn out tailshaft bushing in the transmission. That is the one the front driveshaft yoke rides in at the rear of the tranny. I had it happen to me, and lost a tranny tailshaft housing because of it! :angry1:

AND, after re reading your original posting, I saw the part about the rear seal leaking fluid. I BET you I am right about that bushing!

 

[IXLRrr8]

Nothing is mentioned about the transmission, or any swaps that may have occurred, this could be an out of balance torque converter for and auto or a cut down input shaft on a 4spd.
This could be a swap of 318 to 360 one being externally balanced, one being internally balanced example, you cannot use the 318 vibration dampener on a 360.

 

[Budnicks]

pinion angle & drive shaft angles could be a culprit too...

have you lowered or raised the car or done any leaf spring or suspension work/swaps etc. ??

external balanced engine without the proper damper &/or converter weighting/balancing...

loose converter bolts, loose or broken trans or motor mounts...

I'd look for the obvious 1st,
universals bad,
worn front yoke,
worn tail-shaft bushing or output shaft,
out of balance or bent driveline,
rear end pinion or carrier bearing {usually accompanied by a whine thou},
bent axle or bent rim,
bad brake rotor,
drum lost it's balance weight,
bad tire/s or out of balance...

could be allot of things

just spit-balling here, wild guess with out seeing it & knowing more

Good luck

 

[Street fighter]

Do you hear any Whining noise?

No whining.

- - - Updated - - -

Take the driveshaft out and hold a straight edge to it all around its perimiter. I bet your driveshaft is bent. this could happen from hitting something or it could have torqued a bit from being old and weak. I would really suspect its no longer straight.

New driveshaft new u-joints new tail bushing in trans and new trans mount.

- - - Updated - - -

AND, after re reading your original posting, I saw the part about the rear seal leaking fluid. I BET you I am right about that bushing!

There was no leaking until I had the bushing installed, but there was still vibrating

- - - Updated - - -

Nothing is mentioned about the transmission, or any swaps that may have occurred, this could be an out of balance torque converter for and auto or a cut down input shaft on a 4spd.
This could be a swap of 318 to 360 one being externally balanced, one being internally balanced example, you cannot use the 318 vibration dampener on a 360.

The trans is a727 auto from TCI which have had in the car about 6yrs. New stall has less than 1,000 miles on it, weighted for the 360 engine new drive shaft new u-joints new bushing in the tail housing new yoke and new trans mount.The car is driven about 600 miles a year so there are very few miles on the trans.Like I stated on another post that my seal leaking started after I had the bushing installed.When I removed the brushing it was installed one way and the guy at the trans shop installed it just the opposite. there is a groove in the tail housing at the bottom and there is a opening in the inside of the bushing they were lined up but the trans guy put the groove at the top. do it make a difference I don't know. need to talk to a trans guy.the car have not been lowered. and it have the 360 balancer on it and I have checked it and it's still lines up with the timing tab on the block.do anybody know a good trans man they can ask about the installing of the tail housing bushing, I don't want to pull this trans again if I don't have to.

 

[furyus]

First, does it vibrate in neutral sitting still? That will tell you if it's in the engine/trans. Is it a wobble type of vibration( wheels/ balance), or a drone?

 

[Street fighter]

The car don't vibrate sitting still in neutral or just raising the engine in drive without the shaft in the trans. nor do it spill out any trans fluid when I raise the RPMS up to the point that it would start vibrating, like I have noted in my post everything that I felt would cause the problem was replaced. u-joints transmount, new driveshaft,new tail bushing.thats why I believe it's in the rearend . Like I stated I had my wife to raise the speed up to 55 and 60 and there was no trans oil spilling or vibrating.I don't believe the driveshaft could be out of line. nothing have been added like bushens or anything like that. I hate this quessing game it is causing me more and more money.

 

[Street fighter]

It's like a drone had all wheels balanced.

 

[khryslerkid]

Did the vibration just happen one day, or has it been there since you've owned the car?

 

[Street fighter]

I have owned the car 20yrs , but I just started noticing the vibrating about a year ago, it started small and now it is worst,I don't drive it that much so once I got out of it my mind went to one of the other cars we have.I had plans to find the problem but I never did, now it's worst and need to be fixed.I took it and had the wheels balanced and checked the front end and driveshaft and joints but never had any luck finding the problem, parked it and planned to get back to it.took it to have the wheels rechecked and the guy at the tire shop showed me how the trans yoke was moving up and down so we felt that the tail housing bushing was the problem, I replace it but now I have trans fluid leaking out the tail housing I believe the driveshaft is playing some part in making the seal leak. I am on this and I want to find the problem before I park it again.

 

[Dennis H]

600 miles a year is not enough to keep it healthy. Find it and drive it.

 

[2059]

As Budnicks said first in his post. Could be pinion angle.

I just went through this for different reasons. it's easy to check your pinion angle and it will quickly confirm or rule out that variable. The only thing is; you must understand where you're at right now with your pinion angle and Trans/ Driveshaft angles to know if it needs to be changed/wedged.

Keep us posted.

 

[ZR9B]

Mine turned out to be the driver side wheel bearing...and oddly enough my trans did leak but that was a separate issue

 

[khryslerkid]

Do you have another set of wheels, with tires, that you can swap. Take it for a drive and see if its still there...

 

[kb67mopar]

Look to see if you are missing a weight on the rear drums. Could be imbalanced drums as somebody else mentioned. What rear end is in the car? I'd say pull the differential or take the cover off (depending on axle) and inspect everything you have, make sure bolts are all tight etc. You are looking in the right places so far. There is not much left to check.