HI, I have a 98 chevy 1 ton ext cab 4wd 6.5 4l80e 4.10 (G80) factory limited slip. it has 154000 miles.. i want to X the lube to SYNth what is a good product & weight to use ? also do i NEED to use an posi additive , like in the older posi units ? this truck is going to be used as a wrecker (wheellift) I will be making a trip to TEXAS from here in ILLinois within the next couple of weeks to buy the WHeel lift. thanks in advance.......roger

the best gear oil on the market is by far Schaeffer's Lubricants #267 80w-90 moly supreme. its a synthetic blend and it already has the posi additive in it.

I have had good luck with Redline 75-140. It doesn't require an additive. I preffer the 75-140 wt oil for towing over the 75-90 wt oils.:rolleyes:

Use Amsoil Sever GEar 75W-90 or if towing heavy loads use the 75W-140, no additives needed. Use a true synthetic like the Amsoil or Mobile if you are going to use anything. Blends are OK but coat as much as the real thing.

Greg

www.bobistheoilguy.com/gearoiltest.htm

this compares schaeffers and amsoil

I vote Mobil 1. I have used it for years with great results. Ready available most anywhere as well.