the rear end winds so loud and leaks gear oil why?
Sounds like you need to replace your rear end gaskets and re-fill it with gear oil. If it's been going on too long, you may need to replace the bearings and possibly even the whole rear end. If that is the case, you'd probably be better off purchasing a new rear axle or a new van.
I had the same problem, except for the leaking, got the point that the gears got stuck like if I was pressing on the brakes. I spent $600 to get it fixed at a transmission shop.
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