Ianf406

Told you it was easy!

67 GMC

Wow-This was a long thread! I just did mine last night. I removed the cover (held on with RTV) and wire wheeled it and painted it orange (didn't have any black spray paint). Went to grab my gear oil which I've used for other vehicles and it's Motomaster 80W90. Now it says it meets API-GL4 and GL5 requirements. Is 75W90 "rare" in conventional oils? I only see Royal Purple synthetic (which is pricy).

Please chime in.

cruiser54

Use it.

autosurgeon

I run 85w140 conventional. Since I wheel a few times a year and tow now and then it makes sense. And when i get water in it on a water crossing I don't feel so bad. Royal Purple is great for race cars and street machines. Not so much for mud machines.

JeepMN

Noob question here.

Why would the viscosity of the oil matter if you go through water or not?

67 GMC

Done and Done.
Thanks again Cruiser!

Tackling the rear tonight.

Just to get people excited, I used a paper gasket on the front. I had already ordered it before I saw all these posts and it was in my Easter Basket. Seems to be ok so far. I did it old school -put chassis grease on the cover with paint brush to hold the gasket, a little on the differential housing and it all went on without a hitch (Just like my Jeep -no hitch! lol-sorry).

If I end up with a leak-I will be sure to post my experience.

SteveMongr

That would refer to his term 'conventional'.
After driving through water higher than the axle, the gear oil needs to be replaced. Conventional is less than half the cost of synthetic,.

autosurgeon

Yes cheaper to change. And higher viscosity for higher sheer loading and better temperature handling

DieselDaze

considering the water factor wouldn't paper gasket expand,??? thus adsorbing water??

just saying as I browse my statis threads............ overthought?? maybe so, either way rtv has its roll

then again...............other things do as well.... but some people live life with blinders on, and that fine with me, as I can still see them thru the weep holes

btw, you will never be sucka free, believe me..

67 GMC

Both gaskets are on and holding fluid. I used a drill pump, a funnel and some tubing to fill the diffs to the fill-plug. We'll see. Took more fluid than I though. Close to 3 pints in each on (minus spillage!).

cruiser54

How in the hell did the automotive, trucking, machinery,industries survive all the way up to the 1980s without frickin RTV?

salad

Obviously the only people who worked on vehicles were fine artisan tradesmen.

cruiser54

Versus RTV slathering bozos?

autosurgeon

It is a case of the technology has improved. Paper gaskets are not used by most mechanics for the same reason cork valve cover and oil pan gaskets are not used. RTV holds up better and when properly used as in the correct type for the oil in question provides a far superior seal to a paper gasket.

Ye Ol' Cherokee

I can't believe this thread is still going!

I ... I actually feel... Proud

Seriously though, great info here, and thanks for all you guys' help