So... Update.
I had a pretty good leak from the transfer case. Added the oil stop leak from White Shepherd as mentioned on the boards, and no signs of any leak in over a month.
My question...
I want to now drain and fill with the recommended 75/140 synthetic gear oil. I assume this is the normal procedure...now that the product has worked, time to get new fluid in.
Would the best way be to add the white shepherd to the new heavier oil or do like I did and add it to the old stuff, prior to draining and replacing?

 

IMHO once it has done the job of softening and making existing seals more pliable, and swollen, you would not have to re-apply. If you did, many automotive additives tell you to add "every oil" change, etc. This product says it is once and done, but can be re-applied in the future if more leaks happen. Pix of O ring soaked in it for two days. Here are the FAQs from their website:

How long will the repair last? White Shepherd is a permanent repair!
How does it work? White Shepherd Oil Stop Leak works while you drive. White Shepherd absorbs into the seal to soften, expand & revitalize the size and flexibility to its original condition.
How large of a leak does it repair? White Shepherd will seal leaks in any fluid systems that are seeping or dripping.
How much do I use? One bottle treats 4 to 6 quarts of motor oil.
How long does the repair take? Start engine and drive vehicle or equipment to let White Shepherd circulate. The repair is sealed while you drive (up to 2 days drive time).
How long will the repair last? White Shepherd is a permanent repair!
Can I reapply White Shepherd? YES. White Shepherd does not contain petroleum distillates, which can destroy seals after temporarily expanding them. It is safe to repeat treatment if other seals leak in the future.

 

You should have drained and installed new oil prior to using the Stop Leak.
Once you install the Stop Leak, you are then supposed to leave it there.

 

Agreed, but once it has done the work, I would not believe you need to keep replacing it at every fluid drain interval. But certainly would not hurt for it to stay in with new oil either, and it would be best to start with fresh oil to begin with.

 

Nice to hear it is working for you, I guess I am the only one who had no luck with WS. I was very optimistic, since I had a very slight leak both in TC and front diff, but no change after WS and now I have a new leak from the TC output shaft, despite the WS still being there.

 

Maybe go to 85W150?

 

Thanks guys...as usual piece of mind you are doing things close to correct when you come here.
I will change it soon to the heavier weight and when I see how it does without the white shepherd in there.
nice pic of the gasket before and after.
FYI
After a 1500 mile road trip in two days, from the transfer case back was coated in gear oil. I noticed it after the first day of cruising at 70 MPH. Kind of stressed me out that night in the hotel. Next morning, checked the level and continued on with the mind set that I just got a free under carriage protection done.
The guys at the Indy shop put the dye in to trace it down... Main seal guilty, $500+ to replace the $10 seal. I elected to go with the White Shepherd first. Cleaned up the bottom of the truck and can't see even a drip now. Drove to Victoria and back... About a 300 mile track and still no drips.
No pics ...
I drilled a hole in the lid of the White Shepherd bottle the same diameter as the piece of aquarium hose I had laying around and was able to easily squeeze it into the fill hole on the case.
Driving back to Denver soon and will report if the leak is gone for good.

 

Did you put the whole bottle in TC?

 

I put about 75% of it in the T case. Then added a spash to the engine oil... Just for giggles.