Truck#1 0 Posted September 2, 2007 This sound right to you guys (for a 98 CH w 427/10-sp fuller, and eaton rear axles)? 15W-40 for engine, Synthetic 50W for trans and 75w-90 Synthetic for rear axles. I have nothing to go off of except an older (pre 90) lube book.Thanks in advance.Rob W Quote Share this post Link to post Share on other sites
Noid93 1 Posted September 4, 2007 10-4 Driver, This all sounds correct. One thing i did when i questioned 80w90 in my mack trans was call the dealer. It was easy to tell that it was conventional gear oil in there but you never know what the last guy may have put in it. Two minutes on the phone and there was my answer. Now i am all 80w90 in my driveline(mack rears) but i know your call on the trans is correct. The rears if you pull the plug to check the level it should be fairly easy to tell the difference between the 75w90 and the conventional just by color and smell. We all know the ragged smell of 80w90 but the synthetic i would say has a more golden redish color and the smell is not as curdling. To be on the safe side, call the dealer and ask... Quote Share this post Link to post Share on other sites
