How much labor is it to replace a leaking seal on a transfer case

Hello, the title of your question, about replacing a leaking seal -- I'd check the estimator tool at: www.repairpal.com/estimator Or, check with local shops near you for a real world estimate. Use this link to find some shops near you that can help with your concern: www.repairpal.com/repair-shops As far as engine performance - testing should be performed by an experienced, skilled technician with proper equipment and workshop manual access. There's no way to know what might be influencing your concern until testing is performed.