Soo, I just noticed my rear diff cover is peeled back slightly and I have a slow leak. I suppose this is what I get for running a trail im slightly under built for.

Anyway, I caught it in time and have a diff cover and skid plate for it on order. But in the mean time...

Can i just top off the diff fluid? or should I just flush the old fluid out? I don't know the oil viscosity used in it previously so my main concern is not using the same oil and creating some sort of an issue. At the same time I don't want to put in all new oil as it will likely leak faster. I just want to make sure I don't create an issue in the 3-5 days it will take to get a new cover and re-do the oil. Also would love to hear any suggestions for creating a temporary seal of some kind. It is a SLOOOW leak, but im trying to do all I can.

Also taking diff oil recommendations, 2 door JK that doesn't tow and sees an occasional trail. Currently im planning on 80w90.

One of the rocks below was surely at fault.

 

you should be fine to top it off with 75W90 or 80W90. for the short period of time will the new stuff comes it's really not that big a deal. as long as those gears and bearings are being lubed by SOMETHING, they will be ok.

 

sounds like a plan.

Would you use black RTV for seal or gasket? when it comes to new cover
I got the poison spyder cover and it does come with RTV by default

 

I would give a LubeLocker serious consideration. I've used them for 10 years now and appreciate them every single time I remove a cover. No scraping RTV and they are reuseable. Well worth the small cost IMO. I really like to remove my covers when servicing to get my eyeballs on things rather than just doing a blind drain/refill. Tiny bit of extra work for peace of mind.

 

less work is always good. thats an easy sell. thanks!

 

So i went to top it off today, and to my surprise oil came out of the fill bolt. This made me realise that the driveshaft angle impacts the max fill gear oil level since it changes the angle of the pumpkin. But im definitely ok for now as oil level is high. I do wonder if i will need to put it on jackstands when I do the cover swap to ensure adequate oil level

 

Does it appear that your diff is more pinion up? IMO, I would attempt to get your rig Level; I personally would not have a concern with mine if the rear was slightly higher which would allow for a slight amount more on install. Just Me.

 

So its down a bit. With lift and new control arms it rotates. Same reason I needed spring correction brackets. So its angled down slightly, meaning lower fluid level at the fill point. So yeah im thinking ill need to put it up on jackstands to even it out a bit more

 

If you really wanna lose some sleep, watch some of the Banks videos on YouTube and see how the shape of the diff cover really feeds the pinion bearings. I wouldn't worry about the idea of propping the axle up. You should be able to get the spec capacity in there regardless. I had PSC covers way back in the day.

 

I did watch the banks video, i will admit i was immediately peeved by the plastic cover that was constructed. They left out the horizontal grooves on the inside, which would indoubtebly change the flow of the fluid. Unfortunately we will never know how. Still it definitely made me more aware of the diff intraworkings, which I appreciate