I am in a similar boat as Jerry. My 1973 TR6 is also up on ramps/jacks being prepped for the diff mount repair. While the diff is out, I took the opportunity to change the oil. When I poured it out, I got less than 1 pint of oil out. When I filled it back up it took the full 2.7 pints AND promptly began to leak/run from the pinion seal and slowly drip from one of the axle shafts.
I have the new seals on order because I don't think I have a choice but to replace at least the pinion seal because of the severity of the leak. I am nervous about the pinion seal though because I assumed I had the "late" differential with the collapsible spacer based on my commission number (CF8584UO). However, when I looked closer, my diff has a slotted pinon nut with a lockwire which I believe is a hallmark of the early diff with the solid spacer instead of the nyloc nut with the later units. My diff number is CD53247, but I can't find any reference about which diff numbers ran for which years and I don't yet have the Heritage certificate to see if this is the original diff # (if it even lists it). Is there any other way to identify an "early" diff or can anyone tell based on the number? Does the later model diff still have the hole in the pinion shaft for the lockwire even though it is not used?
If I indeed have an early diff, am I correct that I can safely torque the pinion nut to 90-120 in-lb listed in the manual when it is put it back together?
Sorry for all the questions, but I want to make sure I understand all the risks when I undertake this repair!
Ken