I hit 6000 miles last week and I had been hearing some groaning in 5th gear at low speeds in the rear end. Only in 5th. I researched and searched all the forums and the solution suggested in more than a few threads was an
oil change to
Amsoil Severe Gear 75W90 and a tube of LSD friction modifier.
I did it today, the old fluid was very thick and metallic gray. (wear?) it took 2+ quarts + the friction modifier. Test drive...totally silent in all gears. I'm amazed!
I'm not an
Amsoil dealer/distributor/stock owner. In fact, I think I paid too much: $ 15.50/qt.! ...but worth it.
I also decided to change the Tremec's fluid with 3 qts of Pennzoil Synchromesh. I had found out that it's exactly the same as GM Synchromesh, which PZ, as well as Texaco, manufactures for GM under contract. The old
oil looked golden new and clean but what the heck. It feels no different, just a bit more "definite", not as slick. Some may describe it as "notchier".
