[batarchangel]

Well well well.... I think I may have finally found the culprit in my rotation vibration or at least I am hoping. After a rear end inspection I have found gear oil all over my 9" case as far out as the bolts on the exhaust hangers! WOW! I must be blind! Take a look and tell me what you think.
I know not the best pictures but all I got is my phone. ahahah So I am hoping that the vibration is actually low fluid level in my diff. Hoping I say

 

[1969XR7Vert]

Low fluid level is not going to be the problem, but it certainly could be low with things being that wet. The real question is if something is loose. Did you try grabbing the yoke at the driveshaft and try wiggling it side to side? It should not have any play except rotationally.

 

[benchseat67]

If it has been run that way for a while, I would say it has caused some wear that needs to be repaired. I had the 9 " gone through in the 1973 I sold not long ago. It needed new bearings and seals. Once that was done it was nice and quiet. Looks like yours would do well with an I.R.A.N. (Inspect/repair as necessary). That's an old phrase from my military days.

 

[Cedar Rapids Ia]

What Bob said....check for loose components...could be as easy as a u-joint. New seal, no biggy there either.

 

[batarchangel]

Drive shaft is brand new, along with u-joints, just had it made, what about the rear pinion seal? This issue has been ongoing since the end os september when I got the car. Im guessing that this is the vibration because it doesnt happen until the car has been driven enough to warm everything up and then it begins. Seems like that would make sense,no?

 

[cougarshaman]

Pull the whole thing apart. Change the axle bearings and seals, pinion bearing and seals, and clean the surface on the third member where it meets the housing.
It's the only way to be sure.
And, by now that gear oil is way old and needs to be changed anyway.
This will not cost a tonne of money either. And, it's just good maintenance procedure.
1. Unbolt axles
2. Pull axle shafts out
3. Unbolt 3rd members from housing and driveshaft
4. Pull 3rd member out.
5. Clean, inspect, etc.
6. Reassemble.

 

[benchseat67]

Pull the whole thing apart. Change the axle bearings and seals, pinion bearing and seals, and clean the surface on the third member where it meets the housing.
It's the only way to be sure.
And, by now that gear oil is way old and needs to be changed anyway.
This will not cost a tonne of money either. And, it's just good maintenance procedure.
1. Unbolt axles
2. Pull axle shafts out
3. Unbolt 3rd members from housing and driveshaft
4. Pull 3rd member out.
5. Clean, inspect, etc.
6. Reassemble.

Also....make sure you remove the little thin washers under the retaining nuts. If you don't, the differential won't want to come out of the housing. I found this out by personal experience.

 

[1969XR7Vert]

Drive shaft is brand new, along with u-joints, just had it made, what about the rear pinion seal? This issue has been ongoing since the end os september when I got the car. Im guessing that this is the vibration because it doesnt happen until the car has been driven enough to warm everything up and then it begins. Seems like that would make sense,no?

Doesn't happen until the warmed up, hmmm, that could be tough. Harmonic balancer maybe could do that, not sure what else. Rear end, doubtful, but it still looks like it needs attention regardless.

 

[batarchangel]

WOW! so i was about 2/3 a quart low on gear oil! Lets see if this will make a difference

 

[Cedar Rapids Ia]

I don't think that the low oil would cause it to vibrate...but I have been wrong before.

 

[batarchangel]

And you were right, its still vibrating! AHHHHH!!!! ahahahha one thing after another but Ill be damned if I dont figure this out before December!

 

[Jan Ove]

When you feel vibration in the steering wheel, it´s usually something in the front, when you feel vibration through the seat, it´s usually something in the rear

 

[cougar2]

And you were right, its still vibrating! AHHHHH!!!! ahahahha one thing after another but Ill be damned if I dont figure this out before December!

Just filling it up with fluid isn't going to make any difference. Your going to have to change out the bearings.
Where and when do you feel the vibration?
Do you feel it in your seat?
Is the vibration only when the car is moving and what speed to you start to feel it?
Dose the vibration get worse as you drive faster?
Is it there only on acceleration or coasting as well?

 

[doctordesoto]

put the lube in the read and put the rear end on good jack stands---fire it up and put it in drive---take it up to vibration speed with the brakes slightly on ---if it vibrates as before , its in the driveline some where
doctordesoto

 

[batarchangel]

Rear wheel bearings? I feel it in the wheel, pedals, and seat. Its really hard to pinpoint. It starts at about 50 Mph and slows down after 60 but around 70 it'll speed up and you hear and feel it again. During acceleration and coasting.

 

[Cedar Rapids Ia]

Not trying to be a wiseguy...but are you sure that when you re-installed your drive shaft that it seated correctly into the yolk and isn't cocked a little? Also, that they balanced the drive shaft? Look and see if a balance weight flew off...is there a witness mark where a weight was??? Idler arm?

 

[cougar2]

Rear wheel bearings? I feel it in the wheel, pedals, and seat. Its really hard to pinpoint. It starts at about 50 Mph and slows down after 60 but around 70 it'll speed up and you hear and feel it again. During acceleration and coasting.

Can you hear it as well or just feel the vibration?
Changing the wheel bearings is probably a good Idea along with the pinion bearing and two other bearings in the rear end gear housing. To take the drive shafts out, you will have to pull the drum brake housing off and behind that on the flange where the wheel studs are and the wheel bolts to, you will see a large hole. This will enable you to stick a socket through to get at the 4 nuts that hold the bearing retainer in place for the axle shafts. Once the 4 nuts have been taken out pull the axle shafts out and the bearings will come out with them. You will see the seals for the shaft there as well and will have to be removed actually first. Once the shaft has been taken out then unbolt the nuts around the gear housing and pull it out as well. I would suggest taking it to a shop that specializes in transmissions and rear ends. Have them look at it to confirm weather or not the bearings need to be replaced. At that time though, you should replace the pinion seal and order another seal for the gear housing for when you go to put the thing together.

 

[batarchangel]

The driveshaft only went back one way, the way it came out, I marked everything before removing to insure everything would go back right. How do I tell how many splines m axle is? Without tearing is apart...if thats possible

 

[cougar2]

The driveshaft only went back one way, the way it came out, I marked everything before removing to insure everything would go back right. How do I tell how many splines m axle is? Without tearing is apart...if thats possible

Look to see if you still have the tag on one of the rear end bolts and if so, post what the number is stamped on it.

 

[Bad69cat]

I don't think that the low oil would cause it to vibrate...but I have been wrong before.

Yeah - me too - but it turned out i was mistaken!!:1poke: