Identify this part

Oh...Thats a National 4374

it says 4734 or 4784 , looks like a pinion seal, l but not on a 9"?????

pinion seal or unit bearing?

it is my pinion seal and bearing on the 9" high pinion rear. Yes the 1310 companion flange yoke you see there is in bad shape. It seems to have wore down on the seal side a good bit. I drove the jeep to hagerstown in the bad weather yesterday. Did some work and went back out to make a few stops at lunch. I drove around the parking lot and heard a new sound. Made a few laps around the parking lot and figured it was coming from the rear end. About that time the rear seized up and the rear tires stopped spinning and I slid to a stop on the snow. I got under the jeep to find the third member high pinion in the rear very hot, instantly melt snow hot. I know I put 3 quarts in there like was recommended for a 9" rear. I had a friend give me a ride home 40 miles to pick up the excursion and trailer and went back to hagerstown and picked up the jeep. I was able to back up and then it would move forward a few feet and I slowly worked it onto the trailer. I took it apart today to find the pinion is seized up on the bearing and seal. I cannot remove the pinion. Time for a rebuild already, new bearings, seals and a new ring and pinion. By the way I thought the axle tubes were supposed to have seals in them to keep the fluid out of the axle tubes? Otherwise when you turn corners the fluid will run low right?

Mudslinger's 9 didnt have seals there either. We actually took pictures and I spoke to a tech at Currie. He had told me that the only seal is the one at the wheel side of the tube...I stated the same thing as you.. What happens when you have the jeep on a 45 and all the fluid go's down the tube?????????

I replaced the gasket on the third member to fix a leak and only put 3 quarts in. That is what I was told it needed but I think it probably needed much more than that. Next time I think I will fill the thing until it comes back out the hole.

thats sucks. so it was a 9". i heard that eric had issues with his hi9 under filled too, and there was a big thing on pirate too about people under filling, so your not alone.

The 9" definitely takes more than 3 quarts (I've filled mine often enough to know). Probably closer to 4.