TT typically use 2 5/16" ball. Issues coupling with that ball may mean you need to adjust the locking nut on the coupler. If the issue is its too hard to get apart, do you have any grease on your ball? Have you tried adjusting tv to release pressure (ie inch forward or backward)? Sometimes the tt or tv settles on way or another and puts pressure on the coupler so you can't separate, rocking the tv helps.
2014 Chevy Silverado 3500 SRW Duramax
2011 Zinger ZT26BL-sold
2014 Sabre 34REQS
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