First thing this morning I checked the front differential fluid for level and clarity.
I changed the front differential fluid yesterday. Here's some notes on that:
- my plan is to change fluid for both differentials, manual transmission, and transfer case, as preventative maintenance/upgrading the fluids.
- the front differential was the first step so if anyone has any pointers for the remaining work, let me know.
- I basically cleaned the area with paint thinner before starting any unbolting.
- unbolting went well, a top bolt (Driver''s side) was hard to get at (couldn't use a socket wrench) due to the track bar being in the way. Two bolts on the Passenger's side also served to attach an identification tag to the differential.
- I loosened up the bolts first, the bottom more so than the top, and then started prying with a thin blade screw driver using a rubber mallet, best access being from the Passenger's side lower corner, as the differential is more to the Driver's side. Took some work to get the RTV to let go. Used the same pan I use for oil changes to collect the fluid. Then removed all the bolts plus the cover, after the fluid drained out.
Note: Best to back off the "fill plug" a bit before starting the unbolting, to facilitate it's removal later on.
- cleaning off the orange RTV was a pain while lying on the ground. Used blue shop wipes (tucked in) to keep the pieces of RTV from getting into the differential area. Also used the blue shop wipes to get fluid out of the very bottom of the differential case. Cleaning the RTV off the cover was much easier. Used a putty knife to do the scraping plus a file to file off any nicks from my prying (or any previous prying). Used brake cleaner as well to soften the RTV and do the final cleaning.
- for installation I used Permatex Ultra Black Maximum Oil Resistance RTV gasket maker per their instructions which included finger tightening the bolts and letting things set for an hour before final tightening (during which time I barbecued some steak while the sweet aroma of hypoid gear oil
oozed from my being). Permatex also said to do the final tightening using 1/4 to 1/2 turn on the bolts. I found torqueing up to the 30 ft-lb specs for the bolts fell in that range, so that was good. I could not torque the "hard to get at" top bolt mentioned previously so tightened it well with a small "boxed-in" wrench.
- I had removed the "fill plug" before reinstallation of the cover so next step was to fill the differential with new fluid. For that I upgraded to Quaker State full synthetic 75W-140 GL-5 synthetic gear lubricant. It came in a 1 US quart / 946 ml container designed for pouring. In spite of that "pouring" feature, I had to use a 6" piece of rubber hose, attached to the pouring spout, to get the fluid into the differential case, as things were in the way. Only took a little over 1 container to fill the differential, I was expecting more than that initially. Put "fill plug" in and tightened it, took Jeep for a 10 minute spin.
- rechecked fluid upon return and found a fair amount of aeration which, I assume, can be expected from the fluid being beaten like with an egg beater. Used the Jeep later last evening for about an hour's highway driving.
- back to the beginning:
I decided to check the fluid first thing this morning. All was well, no leaks and the fluid was absolutely clear which indicates no dirty fluid got mixed in. Next job is the rear differential which I may just pump out rather than do battle with the RTV. I never checked to see if there are any reusable gaskets available for the differentials.