Hey, Moses! Great to be on your forum. I have just replaced my rear main seal, timing chain cover gasket and seal this week on my 1999 Jeep TJ 4.0L and is ready for oil. I am the original owner and the engine currently has 120,000 km on it. I am now only using the Jeep in the summer.
I have only used Mopar 10w30 and Mopar filter. Over the years, I have had two rear main seals replaced with no success by the dealer and an independent mechanic.
The last oil change I replaced the oil with Royal Purple 10w30 synthetic and still no success. So... once again for the third time, I decided to replace the rear main seal myself! Can you suggest a good oil and BRAND to use to help combat my issue with oil leaks. Should I be using synthetic? Also, is the 10w30 Mopar oil synthetic now? In the mean time, I will be looking at the installation of the rear main seal, oil pressure and PCV to see why I have had this issue.—Jason