This subject has been discussed many times but I'm wondering what kind of lube you're using in your T-5? Not trying to hijack the thread or go down a rabbit trail but it is possible that using the wrong lubricant could cause a problem like you're experiencing.
I've seen it posted on the boards here that all NWC T-5's use gear oil and all WC T-5's use Dexron II ATF but that doesn't jive with GM factory information. I have a NWC out of an '89 S-10 and the owners manual clearly states to use only ATF. I followed the advice given on another site devoted to T-5's that states to consult the owners manual of the donor vehicle for the type of lube to use.
