2003 AWD - Noted "Stiffness" in Rear Diff

[jlkwiththree]

In chasing down several issues with my daughter's "Frankenvibe" I was working on a full rear brake service when I noticed that turning the hubs took a considerable amount of effort (on jack stands with both rear tires off and brake drums removed). I then checked the rotation with the car in neutral thinking that freeing up the prop shaft would help, but it did not; the prop shaft did not turn. The reason for me doing this work is the result of an initial diagnosis of sticking rear brakes. Some symptomology that led me to that diagnosis:

- The car did not move easily when being pushed
- I heard a brake like squeak from the rear wheels while pushing it into my garage
- Upon disassembly the brake drums fought me during removal
- The shoes where pretty worn and the brakes were unusually filthy inside (just had them apart during an inspection and cleaned in June).

I have tried to remove the fill/inspection cap from the rear diff but is has been on there since 2003. I don't want to strip it so I am hitting it with PB Blaster. I'll try again tonight. On the upside it is totally dry - no axle seal weeping.

Should I be concerned or are these units usually stiff when spun in the way described above. I will finish the brakes tonight and get it back onto the ground and do more testing. Any other ideas on how to measure/test for rear diff issues?

Thanks! John

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[jlkwiththree]

Well I went ahead and put the car back on the ground to test other fixes on the road. Based on some self designed tests I did it would appear I am being a bit paranoid. The car rolled easily and was a breeze to push around the driveway. The test drive also went well. I will, however, change the gear oil tomorrow night with Royal Purple gear oil. It's likely due....

[Chiadog]

You may want to check the temperature of the differential after running the car on the highway for a bit. It is my GUESS that the differential should never get more than luke warm!

[jlkwiththree]

Good excuse for me to get a new tool - a laser temperature sensor. Thanks!

[lannvouivre]

You may want to check the temperature of the differential after running the car on the highway for a bit. It is my GUESS that the differential should never get more than luke warm!

I used to have a melted diff pinion. Should have held onto it so I would have a picture to reply with.