Three problems related to automatic transmission cooler have been reported for the 1998 GMC Jimmy. The most recently reported issues are listed below.
Transmission oil cooling line is leaking from metal attachement. Please give any further details.
The serpentine belt tensioner is an item requiring no maintenance. When it fails the vehicle is completely disabled. The transmissin cooling line failed where it connects to the transmission. This connection point is directly above the exhaust system so when it fails transmission oil is spewed all over the hot exhaust pipes/catalytic converter.
One of the transmission lines loosened, causing transmission fluid to leak out. This could have caused major damage to vehicle. Problem has been corrected. Transmission fluid leaked oil over the exhaust system including the convertor.