4l60e leaking

[GMCBurb99]

Just a quick question about a leak on a 99 Suburban 2wd with 4l60e. I’ve had the engine pulled out for for a couple weeks and yesterday I noticed a puddle of transmission fluid on the floor right under the rear of the transmission, but it was leaking from the universal joint. Is there a vent or something that’s in the slipyoke? It’s never leaked before and the seal is completely dry and thought if there was some sort of a vent it’s just leaking through there from where the front end has been jacked up slightly. Thanks for any info