Transmission squealing noise?

[Dustert73]

Hey everyone, my apologies if this has been answered I couldn't find an answer I haven't tried already. I have a 73 duster 318/904 that has a squealing noise (similar high pitched squeal as like a bad belt or wheel bearing) coming from the back of the transmission area, but it's kind of hard to tell.

It's most noticeable at lower speed, let's say from 15-45 mph. At first I thought it was the pinion bearing in my 8.25 so I replaced it with the original 7.25 and its corresponding length driveshaft (which for sure never made this noise before). And it is still making the same noise so I'd think that eliminates the U joints and rear being the culprit. Could it be something simple as like the rear rubber seal? Or will it require a rebuild? Thanks in advance

 

[TrailBeast]

Does your trans have the output shaft seal with the boot on it?
And does your driveline contact that boot?

If the driveline comes up against the rubber boot it can squeak.

 

[Dustert73]

Does your trans have the output shaft seal with the boot on it?
And does your driveline contact that boot?

If the driveline comes up against the rubber boot it can squeak.

Yes it does have the boot, and no it doesn't aside from the input shaft going into it. I should add that it's not all the time either. Seems like it goes away after driving let's say 20 miles. Then comes back if it sits for awhile. I just checked the fluid and it still looks brand new and it's got the right amount in it.

 

[TrailBeast]

Yes it does have the boot, and no it doesn't aside from the input shaft going into it. I should add that it's not all the time either. Seems like it goes away after driving let's say 20 miles. Then comes back if it sits for awhile. I just checked the fluid and it still looks brand new and it's got the right amount in it.

If it's supper dry where the boot touches the yoke tube it can squeak/squeal there.
The only thing inside the trans that can really squeak or squeal would be a sprag and if it was bad enough to make noise it wouldn't work anymore and the trans would work right.
I guess it could be the rear shaft bearing, but I couldn't imagine it could get dry enough to squeak.
Have you tried running it with the driveline out?
It might drip a little but not bad if you just run it long enough to hear it.
(or an old yoke or plug would work also)
This is what I would do.

Also I take it that it only does it when rolling, right?

 

[Dustert73]

If it's supper dry where the boot touches the yoke tube it can squeak/squeal there.
The only thing inside the trans that can really squeak or squeal would be a sprag and if it was bad enough to make noise it wouldn't work anymore and the trans would work right.
I guess it could be the rear shaft bearing, but I couldn't imagine it could get dry enough to squeak.
Have you tried running it with the driveline out?
It might drip a little but not bad if you just run it long enough to hear it.
(or an old yoke or plug would work also)
This is what I would do.

Also I take it that it only does it when rolling, right?

Yes, only when rolling. I'm going to try that and see if it goes away. I'll report back here with what I find. Thanks for the help again trailbeast

 

[Dustert73]

Just an update to what I've found. When I removed the driveshaft it seemed to stop making the noise. I know it's the wrong thing to do but I just cut the boot back a little so it wasn't touching the yoke. It hasn't made the noise since.

 

[TrailBeast]

Just an update to what I've found. When I removed the driveshaft it seemed to stop making the noise. I know it's the wrong thing to do but I just cut the boot back a little so it wasn't touching the yoke. It hasn't made the noise since.

Cool.