OK my 71 rear end problem. I removed the axels from the center diff. The hubs rotate freely, good news; however the rear end will not turn at all it rolled prior to the care being taken apart for paint and put back together with new brakes rotors pads calipers lines etc. do i have to replace my diff or am i missing something?

 

Do you have the shop manual??

https://www.ebay.com/itm/40597070109...id=21388819155

For my series 2, there is a whole chapter on the rear end in the 4.2 manual (Bentley pub.) . It's possible something is overtightened somewhere. On my 4.2, there are any number of washers, spacers, etc. that if not reassembled in the correct or right order, or left out, could make a difference.

Have you posted this question in the JagLovers forum? There are also some EXCELLENT rear end videos on YouTube.

Here's an AI take on it, for whatever that's worth:
AI Overview
1971 Jaguar E-Type rear end issues
If your 1971 Jaguar E-Type's rear end isn't rotating, it can indicate several potential problems within the independent rear suspension (IRS) and drivetrain. Here are some key areas to investigate:
1. Seized components
Radius arm bushings: The radius arms connect the rear suspension to the chassis. If the rubber bushings inside these arms seize, they can prevent free movement of the suspension components, including the rear end rotation.
Hub carrier bearings: These bearings are crucial for the wheels to rotate smoothly. If they seize due to old grease or wear, it will impede rotation.
Brake pads and rotors: If the car has been sitting for an extended period, the brake pads can rust to the rotors, effectively locking the wheels.
Universal joints (U-joints): Worn U-joints in the half-shafts can cause clunking or impede rotation.
2. Differential problems
Limited-slip differential: The 1971 E-Type likely has a Powr-Lok differential. If the wrong type of oil or an insufficient amount of friction modifier additive is used, it can cause the clutch plates to bind and prevent smooth operation, potentially leading to a locked differential.
Internal differential damage: While less likely if the car hasn't been driven recently, internal damage or wear within the differential itself can also cause it to lock up.
3. Other possibilities
Gearbox or driveshaft issues: Problems within the transmission or driveshaft could also indirectly prevent the rear wheels from turning freely.
Broken components: Although less common, a broken half-shaft or other component could also be the culprit.
Troubleshooting steps
Safety first: Safely lift and support the rear of the car on jack stands.
Wheel rotation: Attempt to manually rotate each rear wheel individually.
If neither wheel rotates: The issue is likely within the differential or a component common to both wheels, like the driveshaft or gearbox.
If one wheel rotates freely and the other doesn't: The problem is likely localized to the affected wheel's half-shaft, hub carrier, or brake assembly.
Brake check: Ensure the parking brake is fully disengaged. Visually inspect the brake calipers and rotors for any signs of rust binding. If necessary, try to carefully pry the brake pads away from the rotors to see if that frees up the wheels.
Radius arm inspection: Examine the radius arm bushings for signs of seizing.
Differential fluid: Check the differential fluid level and condition. If it looks old or contaminated, changing it (along with the proper limited-slip additive if applicable) might resolve the issue.

 

So you turn a the propshaft coupling and nothing will move on the output flanges ? Hm.
I think the best thing to do now is take off the rear cover on the diff and inspect it. One component of the diff can seize it up, and if it comes loose during driving causes such damage, that you need a replacement diff. This liitle part, is called the Pinion Mateshaft Locking Pin, and came loose on my Mark 2 back in 1988 on a beautiful summer day as we were driving to a Jaguar rally. There was a bang, then a loud clonking noise. We couldn't drive the car, so were recovered home and never got to the rally ! How this pin came loose I never found out, but the car needed a replacement diff. So make sure you inspect the diff.

 

Brakes stuck on?

-Dave

 

Is the transmission in neutral?