My truck has started leaking from the pinion seal on the rear diff. Not a major leak, but it is damp around the seal and the front of the differential housing. It's not enough to drip yet. No symptoms of driveline looseness, I just noticed it when I took a quick look under the truck the other day. I am hoping it is just that the seal has become worn out from 12 years / 155,000 miles of use. The leak had to have started within the last month. I check for leaks whenever I change the oil and the diff was dry at the last oil change about a month ago. Would it be a good idea to go ahead and order a Speedi Sleeve for it? How common it is for a leaking pinion seal to be associated with wear on the flange? I can't find a Speedi Sleeve in stock locally, so that kind of suggests to me that it isn't that common to need one (same p/n for all 7.5"/8.8" axles), but it could also be that most people just replace the seal and don't care/notice what condition the flange is in.