Jim, my transmission shifts great when warm with 75w-140 Lucas trans and diff but it is impossible to shift when it is cold, even 60 degrees. I start out in the morning and I can shift through the gears just fine at a standstill, but as soon as the car moves, I can't shift it into any other gear unless I match the engine speed with the trans speed and slowly let out the clutch so it will slip into gear. After about 2 miles, it will shift with a grind. After about 4 miles, it will shift without a grind but it feels stiff. After 8 miles, it shifts great. It seems like the fluid is too thick when it is cold so when I changed the fluid I used a 50-50 mix of 75w-140 and 75w-90. It only improved it a little so I added 3 oz of the Lube Gard. I did improve it a little but not near enough. Did you put all 10 oz in? Instructions say 1 oz per quart of fluid. Maybe I'll have to use only 75w-90. Roger