I bought an 8 3/4 741 case 3.55 gears non sure grip to replace the burned up 9 1/4 in my 91 power ram 150 truck. I removed the axles and the third member and cleaned the housing real good and installed new inner wheel seals. The wheel bearings are still in good condition so I figured I would re-use them. But I want to grease them up before I put the axles back inn.
How do I do it with the bearings still installed on the axle shaft? Do I need a special grease tip? Then do I just squirt grease in between the rollers?

Yep, get the grease tip that looks like a hypodermic needle. Clean the bearings real well, then insert the needle between each roller with the idea of displacing as much air as possible.

Cool that's what I figured. I have a needle grease tip but it's not thin enough to really get in between the rollers. I'll go check out the part stores tommorrow.

I'm sure someone on here has used rtv gasket maker for the third member gasket correct?
I got a question, I used the right stuff gasket maker by permatex and I spread it around on the housing with a thick bead and then I went back and made sure there was rtv around every stud. Then I dropped the third member on and was surprised at how much rtv came oozing out. I just grabbed a rag and put it around my finger and went Round and smoothed it out. I should be good to go right?
I mean I've used the rig stuff gasket maker before and I've always had excellent results with it. I guess I just used a little more then I needed to. I'm going to let it set up and dry for a couple days before I add oil to it.

Using RTV you want it more on the inside of the stud "circle" on a rear end housing but you will be fine & the right stuff sets up very fast. I sure hope that pig ain't coming out soon!. that needle that snaps on the end of your grease gun as said works perfect for tapered bearings already installed on a shaft.

I've used gasket in a tube before on the third member without any ill effects. I typically let it set up for an hour before shoving the pig home just to let it skin up and minimize the ooze.

Hopefully before you did that you checked the flatness of both the housing and the third member to make sure there was no extra gasket material, nicks or burrs to impact the fit of the two pieces.

Greasing the bearing with the needle method works well. The alternative is sitting there for 30 minutes pressing grease into the bearings by hand, moving the bearings around, and manipulating it enough to work the grease into everywhere.

I kept the right stuff rtv away from the inside as best I could cause I didn't want it to fall into the housing when I set the third member on. But I laid a pretty thick bead down on the housing and then after that I went around every stud to make sure every stud had some rtv around it as well. I let it sit there for about 15 to 20 minutes then I dropped the third member on. On the bottle of the right stuff rtv it says assemble parts imidiatley. So I didn't want to wait too long.
I think I will be ok, like I said a lot came oozing out, and that's most likely cause I used more then I needed too, but I didn't want this thing to leak, I didn't want to be removing this third member while its under my truck, so I laid a thick bead of it down.
I cleaned both surfaces with a razor blade and brake cleaner untill nothing was showing up on my rags anymore and I know I scraped all the old gasket off with the razor blades, cleaned the housing its self with brake cleaner and cleaned the third member with brake cleaner and used compressed air on the housing and third member before going back together.

Maybe I will fill it up with gear oil before putting it in my truck and let it sit on the jack stands for 24 hours with oil in it, to make sure it's not going to leak, cause if it is I'd rather remove the third member in my garage then under my truck.

It's not going to leak. My Suburban is more than 10 years from me checking inside and then using TRS for the gasket. Nary a drip. That's what factories use to make differential gaskets now. In other words, they don't use a gasket, they use The Right Stuff.

BUT, it would have helped you to read the directions. I'm sure it says somewhere to use a thin layer. A heavy bead is not going to make the seal more secure, just give you more to clean up.

As for the material squeezing into the inside of the rear end, I imagine it would, but after 10 minutes of driving it has been blended into the lube and I doubt it's doing any harm.

The Right Stuff cures instantly upon being deprived of air, like when two surfaces are clamped together. I have literally installed something using it, put the tools away, topped off the liquids and driven 600 miles. Nary a drop of leakage.

So it's different from the typical silicone, which cures at room temperature by grabbing water out of the air.

Every time the topic comes up, there are posts saying it sticks the two parts together better than JB Weld. I haven't had that experience. I generally use a thin putty knife to separate.

But follow the directions when you put things together. Manufacturers go to great lengths to find out and communicate the best way to use their product.

I am convinced that more gaskets are installed wrong than right. We always think we know more than the people who design, build and sell the stuff for a living. That's known as hubris, which leads to a fall.

R.

But us old guys have plenty of time to do it this way...

(1) I learned sumpin today (2) he wont be smilin when (if) he has to clean TRS in/around all those studs (3) Hubris, Dog I will look that up. I agree, like the one guys' sig says; "common sense, the least common of all the senses"!

I did read the directions on the can of the right stuff gasket maker, this wasn't my first time using the right stuff gasket maker, I've used it for years, used it on all my differential covers, I use in place of the end gaskets on my intake manifold, I've used it on valve covers before too. It says to cut the tab to whatever size you want the bead to be, I didn't lay a ridiculous amount of it on, but I did lay a thick bead and went around each stud with it.
I don't think it will leak ether because I've always had pretty good luck with it, the only times I have had leaks when using this stuff was when I didn't put a thick enough bead down.
I bought the grease needles for the bearings from Napa today, the part number is 700-1193 and they are called grease injector needles in case someone else is doing this too and needs the needles. They are really thin and look like they will work great.

So what's a good grease to use on the 8 3-4 wheel bearings? I have some Napa wheel bearing and chassis grease, it's white lithium grease. Then I have some valvoline synpowerngrease which says it's good for wheel bearings as well. But the valvoline synpower has some moly in it. Which one would you use?

The valvoline is a bit thicker and the Napa brand is a bit tackier

So I decided to use the Napa brand wheel bearings and chassis grease on the bearings cause that's what I had in my grease gun. I put the drivers side axle in first and I noticed that with it all the way in and bolted up that when I turn the axle the pinion yoke doesn't really move, it kinda does but not like It should, when I i stall the passenger side axle then the pinion yoke will turn when I move ether the drivers side or passenger side axle shaft, is this normal? It's a non sure grip 741 case.

I have a really quick question:
Once the rear axle is in and the level of oil is correct, why do you need to grease the bearings? They are sitting in a layer of oil. In big trucks the front axle is typically oil bath and they go 4-500,000 miles if needed. I could see if wiping the bearing with grease before install so you don't go dry. I am not knocking your info, I just don't understand why.

Also, Napa and Advance Auto sell a gasket for the rear center chuck. No rtv, no waiting for dry or goop mushing out. Again... not debating your reasons, I just do not like silicon especially with oil submersion. I have not has good luck with it as a full on gasket. I did however have a lot of luck with an anaerobic sealer.

Good luck.
Joe

The wheel bearings on the 8 3/4 are not lubed by the gear oil, that's why I greased them.
If you look inside an 8 3/4 there is an oil seal in the housing on each side which is called the inner wheel seal, it keeps the gear oil from the bearings. So you have to grease the wheel bearings before installation. And Im aware of the gasket for the 8 3/4 third member, my local part store didn't have it in stock and instead of ordering one and waiting on it I decided to use the right stuff gasket maker, which in my opinion works better then a paper gasket anyways.

I FAR prefer the felpro fiber? gasket myself. I spray it with oil so it will not stick so if I have to change a pig it'll come right off. The mating surfaces are wide & I've had good luck with them sealing with this if the surfaces are squeaky clean. RTV/TRS will definitely seal but getting it off in/around the studs to R&R a pig is something I do not want to do. As said you grease the bearings with quality grease (I prefer Kendall "blue" or MP "green" but there's many good types out there and the gear lube is for the ring and pinion in the center & some sloshes into the tubes but the seals keep it from reaching the bearings/or further out which you dont want (it's not a good lube for bearings/& it will contaminate brake linings).