When putting new fluid in, how do you know what the level is, is there some sort of dip stick?, What type of fluid should I use (truck has 14,500 on it). Is this a do it yourself thing, and how messy is this going to be?

 

Loosen up the bolts holding the diff cover on and let the old gear oil drain out. Remove the cover and clean out any sediment in the bottom of the diff.

Re-install the cover using the same rubber gasket (reusable). Do not over tighten the bolts.

Install your favorite 75-90 gear oil to approximately 1/4" below the fill hole. DC says 1/4" below, +/- 1/4".

If you choose the Mopar gear oil, it will probably be quite expensive ($21.00/qt.). However, I have recently heard that the some of the dealers are becoming more competative with their pricing. I was able to get the Mopar stuff for $15.70/qt., a couple of years ago.

This last time, I installed Red Line 75/90 & was able to get it for $7.00/qt. It's probably a better quality gear oil than the Mopar stuff, also. I've read a lot of good stuff about it.

BTW, there is a website that will have more information than you will want to read about lubrication subjects including gear oil. It is called " bob is the oil guy.com". It's a free website but, you will have to register.

Hope this helps.

Joe F.(Buffalo)

 

Make a bend in a paperclip and use it to determine your fluid level. Unless things have changed, your truck should be filled to 1/4'' +/- 1/4 below the fill plug. In otherwords, fill it to a minimum of 1/2'' below the fill plug. This applies to both axles. However, I would double check your owners manual to be sure of the proper fluid level.

 

When it dribbles out the fill hole, its full - screw in the plug and torque it properly. No guess work & no fancy clips required.

 

I second what bulabula said. Fill it until it dribbles out the hole. Won't hurt anything. Since I pull a 5er, I also use 75W-140 syn fluid.

 

1/4" +/- 1/4" in my books means it is OK to fill to the fill hole (let it dribble out) and this is what I did on mine...I also used the Mopar 75w140. Another thing to is don't go by the spec for the cover bolts in the manual... I did and wound up shearing off three bolts, just go tight enough by hand and then you won't need to worry about finding new bolts. I personally don't believe that the torque spec is correct and should have known better before attempting to torque the bolts to it.

 

When I filled my rear below the filler hole it actually made noise at starts when turning (maybe it's the way the gears in the anti-spin work), but kind of concerned me. I parked the truck with the rear end slightly up hill, opened the fill hole and got about another 1.5qts into it - been quiet ever since. I'd recommend that you fill it til it runs out on perfectly level ground.

 

At 15k the OEM fluid looked like black snot. I filled with Mobil 1 75W90 to the holes, and at the next 15k it looked like a darker olive oil. I refilled with Mobil 1 75W140 to the holes and it runs quieter. In both cases I initially had some fluid leaking at the ends of the axles, so filling a bit below the hole per spec is probably the better way to go.