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Discussion Starter #1
When coming to a stop, or taking off slowly I'll hear a whine from the diff. What's odd is as I come to a stop, right before that the whine increases in pitch, like something's spinning faster...but there's nothing I can think of that would make that noise. It's not the tranny shifting as I'm only going 5 mph... It's that last few feet before a stop the pitch gets higher..

Any ideas what that may be. Doesn't seem to be causing any issues....just an odd noise.
 

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Do you have an open diff, or trac-loc? Have you done a fluid change ever? As long as the fluid is full it should be quiet. Are you sure it's the diff?
 

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Discussion Starter #3
Yeah it's the diff, coming from the rear.
Yesterday I did a hold brake, floor gas and only one set of skid marks, so I have an open diff.

Never changed, car only has 84K on it, not sure when schedule to change is. No leaks anywhere...

Just odd it does that..
 

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Discussion Starter #4
is there a drain port in that pumpkin? Looks like taking the back off is a PITA
 

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is there a drain port in that pumpkin? Looks like taking the back off is a PITA
No, and whereas yes, it's less of one than when a diff locks up on the interstate at 75MPH ...

RwP
 

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I'll have my mechanic change it then. Save me the hassle. :)
This is another super easy job.
The bolts are all obvious. and you just need to put the rear end on jackstands and support the rear pumpkin while you unbolt the rear support (jack is fine).
-g
 

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This is another super easy job.
The bolts are all obvious. and you just need to put the rear end on jackstands and support the rear pumpkin while you unbolt the rear support (jack is fine).
-g
Oh, and don't support the rear end by the wheels; they should be free hanging. You can use a jackstand under the lower control arm, though.

RwP
 

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Not trying to be negative, but I doubt a fluid change is going to fix a noise like you describe. Unless the fluid is low or somehow has water in it; the original diff fluid should last well over 100,000 miles in an open diff. It is always good to get fresh fluid, but without the trac loc clutches it's not something that has to be changed often. If your Tbird has always made this noise, it could well be just how the gears mesh in your differential.

I know you said you are sure it's your diff, but it's not uncommon for our transmissions to make a little noise like you described, at low speeds.
 

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Discussion Starter #10 (Edited)
Not trying to be negative, but I doubt a fluid change is going to fix a noise like you describe. Unless the fluid is low or somehow has water in it; the original diff fluid should last well over 100,000 miles in an open diff. It is always good to get fresh fluid, but without the trac loc clutches it's not something that has to be changed often. If your Tbird has always made this noise, it could well be just how the gears mesh in your differential.

I know you said you are sure it's your diff, but it's not uncommon for our transmissions to make a little noise like you described, at low speeds.
Could be that as well. I'll put in neutral see if coasting does it too. Tranny is getting another look next week and I bought new filter and fluids (Mercon-v) and gasket. I'll have them take it off again as there's no reason a tranny should jolt like that. I see no vacuum leaks (holds 50 psi at idle and throttle), or misfires...rear diff has new carrier bushings as well...poly.

I'm wondering if an OD band is worn, or they didn't replace it... Perhaps the car is slipping in and out of lock in OD while coasting and that jolt is it re-engaging. I don't know enough about AOD's to really know for sure though.

Where do you add fluid to rear diff? is there a bolt in the rear cover to add once it's put back on? I thought the rear pumpkin cover had several things attached to it...
Like this?
 

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I circled the fill plug.

I stick with a name brand; but a lot of people just build a RTV style form-a-gasket on the diff cover.

Might want to consider a "better" diff cover (possibly a finned one for better heat dissipation); but it has to be one for a IRS, so best choice is to check SuperCoupePerformance or SpinningWheels.

Edit: Oh, and that bolt holding it to the rear mount is loose; GET IT TIGHTENED UP SOONEST!

RwP
 

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Discussion Starter #13
Not my car, image found on internet :)

what about the lower left bolt there? Is that a drain?
 

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Not my car, image found on internet :)

what about the lower left bolt there? Is that a drain?
It is; but there isn't one on my diff cover, nor on the cover on my "spare" 2.73 TL diff (planning to get it rebuilt with the 3.55 gears onna deze daze)

RwP
 
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