1968 Rockwell T221 silly question

[vectorit]

Hey all, I am just curious what the best process is to drain the old oil out of a T221 while it is still in the truck?

I am always adding oil, since it leaks like any other T221. But the oil drips are black as can be, which makes me want to try to flush out the old oil and add all new lubricant.

On the drivers side, there are two plugs. The highest one is the one I use to add oil, and I guess I could pull the lower one to drain but it is not at the lowest point of the T case. So I am pretty sure not all the dirty lubricant would be drained...

Also, what's your favorite lube to use in the T221? I have always used the general purpose lube the manual recommends, but just wondering if there is something better out there?

I have been tempted to use a heavier grade, since now I am in the summer months. The garage temps alone get over 100 degrees, and my Rockwell and Eaton axle weep oil just sitting in the garage. While driving in the heat it gets pretty messy, so I'm wondering if a heavier viscosity will reduce all that mess? Or is it even worth it?

[Yukon Jack]

I use 80W90. No good suggestion about how to get the last bit of gear oil out of the transfer case.

[maxwoof]

Hi. I just did the oil in my '62 about a week ago. I ran it until it was hot, and then let it drain. I jacked up the passenegr side too, to get more out. Then sprayed brake cleaner in the fill hole and let it drain, and wiped up as much as I could with rags. Repeated the process, and let it drain over night. Got myy fingers in the drain hole and wiped up as much as I could. Mine was leaking ftom the rear output seal - I got a new one from RockAuto. You need a 1&5/16" socket to get the yoke off, and a puller. I did not need to remove the bearing cover like the manual says - it came right off from the outside. No more leaks from there. However, I still need to do the input shaft, and the bearing retainer opposite the output shaft weeps. It has no gasket, only shims. I will try smearing RTV around it. I had success with this method on the front differential from an 89 4x4. Good luck.

[maxwoof]

Also, I used plain old 80w90 oil. My understanding is that these things run hot anyway, so, you would probably be ok with the 85w. I used it in my rears because I had a lot of it at the time. My experience is that the thicker oils will not reduce the leakage mess however.

The oil that came out of mine was very thin. I will say that the new oil has quieted things down quite a bit.

[vectorit]

I kinda figured that jacking up one side of the truck was gonna be the best answer. No Problem, I can do that!

I have never used "Rock Auto Parts", are they the only one that carries T221 seals and bearings these days? I need to fix a couple on mine..

[jeffspower]

75/140 synthetic is commonly available around here, at least in 5 gal. buckets. I'm not sure if I have seen it in little bottles though. I don't know if it would leak less hot or not. Synthetics are supposedly "leakier" oils.

I used to work on a power companies 6x6 with enclosed front knuckes that were worn bad and leaked terrible. We tried some Model A Ford gearbox oil and it helped. They call it "600w" but they say it is really about 240w.

http://macsautoparts.com/oil-fluid-f...0R3CHL1069113/

[maxwoof]

rockauto.com. I don't know if they are the only ones with seals, but I got a lot of stuff there for my '62 and the prices have been good and quick shipping.