Transaxle

• Chevrolet technical service bulletins (TSBs) indicate that transaxle leakage is a common front differential problem on the 1998 Tahoe. TSBs report that the transaxle, a mechanism that combines the transmission and differential, leaks from its shaft seals.
  
  

Symptoms

• Transmission difficulties are an indicator your transaxle may be leaking. Transaxle leakage may create a lack of lubrication, which can cause transmission slippage and difficulty shifting gears.
  
  

Solution

• The most common cause of transaxle leakage is a broken transaxle seal, which requires replacement. If a seal is not the culprit, oil pan gasket replacement may be required. A last resort in transaxle repair is transaxle replacement, which can cost upward of $2,700 (as of March 2011) according to Auto MD.