Blown Posi???---noobie

[BlackDime]

First I would just like to say that I am a noobie to my truck and the site but am really excited because there is a lot of very helpful info on here that will come in handy. Ok, I recently bought a 2003 S10 ZR5 in Sept. 2008 because I totaled my 1998 S10 Blazer over the summer : (. The truck is spotless and had about 45K miles on it. Since I bought the truck I have since put about 5k miles on it and have had no problems. As soon and the weather breaks I will be changing all of the fluids in it. Anyways, according to the original window sticker for the truck I have a locking rear axle with the 3.42 gear. I have had no problems with the truck but as of the last couple weeks my "locking" rear axle has been a one-wheel wonder. To the best of my knowledge it is not making any unusual noises or anything like that to clue me in that the posi is truly broken however the other day I had to put it in four wheel drive to get up a very small incline because only one wheel was spinning. What do I need to do to check to see if the posi is truly broken? What is the best way to go about fixing it? If it is in fact broken and I have to open the rear diff. would that be the best time to install a rear locker that I am considering buying? Thanks for all the help!


--Scott

[HenryJ]

First thing to do is look in the glove box and find the G80 RPO code.

If it is there, that confirms the Eaton GovLoc. I believe it was more commonly installed with the 3.73 gear set, that is why I question if you have one.

Next would be to pull the rear cover and change the lube. It was to have been done at the first engine oil change and most did not get changed.
While you are there relocate the differential breather. It is located to fill the differential with water and needs to be moved.