Some questions about changing the fluid in the diffs on a '06 TJ, first time I have to do it:
1. The maintenance schedule mentions that the fluid in the diffs only need to be changed when the car is used off-road, trailer towing, commercial service, etc. I just use the TJ for normal use, never off-road, does that mean I never have to change the fluid? That doesn't sound right.
2. I read the write-ups on how to change the fluid and it seems like a big hassle, I don't understand why there is no drain plug, or why there is no aftermarket cover available with a drain plug. Do other trucks have the same diff cover design? Searching online I found LubeLocker gaskets, are these as good as a RTV gasket? Do you ever need to change the LubeLocker gaskets (i.e. do I need to get a few in stock)?
3. What about just sucking out the fluid with a handpump through the fill opening, is that possible or will you never be able to wiggle the rubber hose of the pump to the bottom of the diff? To get the last bit out you could even flush it a few times with some fresh fluid. I suppose the changing of the fluid is the important thing, or is cleaning of the diff's inside also needed, do you get there the same metal chavings as in a manual transmission?

 

I just recently changed mine, I had to use RTV to seal it back up. The maintenance schedule should be every 15,000 miles, more if off-roading. I tried the hand pump on my front dif and it didn't work well at all, I even tried flushing a few times.

 

Changing the diff fluid is about as easy as chaning the engine oil. I bought the Lube Locker gaskets for mine and it makes it even easier to change, especially since mine spend alot of time off-road & daily driver so gets changed about every other month depending on wheeling conditions or deep water holes.

Taking the cover off is the best way, cause then you can inspect you gearing each time to make sure nothigns wrong with the teeth or worn parts as well.

Chris

 

1. I would change it anyway. It doesn't cost that much and it is a piece of mind thing for me. If it has gotten contaminated with water, you will have huge problems.


2. Not sure about other axles, but every D44 in a TJ had two plugs. A drain and a fill. I would bet all Dana axles do. Are you sure you don't have a drain?


3. Sucking it through the fill is how dealers do it. That is fine to do. I would crack the cover the first change to get all the metal out. That is probably over board unless you know you have a problem. Changing the fluid is the important part. If you see a lot of metal on the magnet on the plug, I would crack the cover. Otherwise just leave it and use the drain and fill.




Changing diff fluid is easier than changing the oil IMO. No filter to deal with spilling. Give it a shot.

 

unfortunately the tj 4 bangers don't have d44's, they're d30's (i'm pretty sure). they only have a fill hole.

 

We had a 4 banger TJ, they do not have drain holes in the diffs as they don't have Dana 44's. It's really quite easy to change the fluid, just take a few bolts out and catch the oil in a pan when the cover comes loose. You can look things over and clean the housing and gears while it's open. I used RTV to seal the covers back on. Then just fill them up until oil runs out the fill hole. I put synthetic Mobil 1 in when I do my diffs. Piece of cake really, go for it.