Do you have to drop the transmission replace seals on a 90 Jeep Wrangler?

Generally, yes, you will have to at least partially drop the transmission to replace most seals on a 1990 Jeep Wrangler's transmission. The exact procedure depends on *which* seal needs replacing (input shaft seal, output shaft seal, etc.) and the type of transmission (manual or automatic). Some seals might be accessible with the transmission partially lowered or with clever maneuvering, but a full drop is often the most practical and reliable method to ensure proper seal installation and prevent leaks. Attempting to replace seals without adequate access significantly increases the risk of damaging the seal or other components.