I'm slightly reticent to post this question, but here goes ...
I see recommendations all over the place as to what oil to put in a Hewland dog box. Mine is a DGB with a 400 hp motor in front of it. Seems many recommend either dino GL-5 like 80w90 or 80w140. I saw one respected vendor recommends Redline shockproof. I'm pretty sure that is what was in mine when I got it. Seemed to be a lot of goop in there when I opened it up so I've been using 80w90. Curious to hear what others are using.