A D44 doesn't use a crush sleeve , there are pinion bearing preload shims instead.
How simple is that , a torque wrench will suffice to fasten the nut. A new nut is required , these are not to be re-used. Wanna know what the preload is now ? , measure the rolling torque with a meter type torque wrench . It get's a little more in depth and can be done a couple of ways. All you are doing is a seal replacement though , so pulling the yoke , replacing the seal and torquing a NEW nut isn't rocket science. I like the extra security of red loctite AND a NEW pinion nut.
Why a new nut ? .......... if you reuse the old nut and it doesn't maintain clampload , a potential catastrophy could follow , hardly worth it for the $5 or so a new nut is worth. A backed off pinion nut may result in a pinion gear running amuck , very expensive !