8 3/4 rear end confusion

-
Hello everyone, I have another update. After almost a week straight of rain, I was able to get outside and take out the passenger side axle to see if the button is still in place. It is not and I can't see this one laying there the way I could see the driver's side. I guess this means I have to open the dif and remove it. Question.... does the entire dif have to be removed from the vehicle or can it be left on and I just take off the "cap".... if that's even possible with these. If the dif has to come out, do I have to take out the axle housings with it? I've never done this before so I apologize if it's a dumb question. Thanks everyone
 
the housing can stay in the car.

pull the axles out, drop the drive shaft, and then undo the 10 nuts and pop the center section right out.

and by right out, i mean grunt and cuss and have something ready to catch it. or use a jack. them bishes be heavy. you'll need a new gasket, unless you raw dog it and just silly-cone that bad boy back.
 
340 RR said:
Hello everyone, I have another update. After almost a week straight of rain, I was able to get outside and take out the passenger side axle to see if the button is still in place. It is not and I can't see this one laying there the way I could see the driver's side. I guess this means I have to open the dif and remove it. Question.... does the entire dif have to be removed from the vehicle or can it be left on and I just take off the "cap".... if that's even possible with these. If the dif has to come out, do I have to take out the axle housings with it? I've never done this before so I apologize if it's a dumb question. Thanks everyone
Click to expand...

You may still be able to fish that other side of the thrust button out with a magnet, I’ve done it before. The only place they really sit is right at the bottom of the housing, so if you can get a magnet in there you can usually get them.

Something like this…

Performance Tool W25934 Performance Tool Magnetic Retrievers | Summit Racing

IMG_6486.jpeg
 
I purchased a flexible magnet and was able to fish it to the bottom of the dif. Couldn’t get ahold of the button but each time I brought the magnet out, there was lots of ground up (flaky) material that got caught by the magnet. Now I’m thinking the previous owner had ran the car with the button at the bottom of the dif and completely tore it apart. I’ll be taking out the dif and cleaning it and may need to rebuild it. The previous owner had the wrong rear brakes on the car and had taken off the self adjuster but it still has stock bearings so I wouldn’t put anything past this guy. We’ll see… thanks everyone
 
340 RR said:
I purchased a flexible magnet and was able to fish it to the bottom of the dif. Couldn’t get ahold of the button but each time I brought the magnet out, there was lots of ground up (flaky) material that got caught by the magnet. Now I’m thinking the previous owner had ran the car with the button at the bottom of the dif and completely tore it apart. I’ll be taking out the dif and cleaning it and may need to rebuild it. The previous owner had the wrong rear brakes on the car and had taken off the self adjuster but it still has stock bearings so I wouldn’t put anything past this guy. We’ll see… thanks everyone
Click to expand...

Ouch!

You’ll have to pull the diff and completely check it out, if there was that much metal in there you should rebuild it or at least change out the bearings . Tapered axle bearings and no end play adjuster must have been pretty entertaining, especially if the thrust button was already MIA at the time. Those axle bearings probably should be replaced too if you haven’t already.
 
I pulled the diff and was able to find the second button at the bottom of the casing. The button honestly looks completely intact so idk what that material is from. It does seem like there are some shavings throughout the gears. Don’t know if I can just hot tank the entire thing or if I have to change out the bearings like you said bluNBlu. I’ll have to do a bit more digging to see if there was any damage. Also, there was absolutely no fluid in the dif housing…not a drop. Maybe that explains the shavings. Might have to do the gears as well but again, this is all new to me. Will continue to update with more info, thanks guys.
 
oh wow. super bummer on that being bone dry.

bearings are mos def roached. hopefully you can salvage the gears.
 
Hey guys, hope everyone is doing well. I’m in the process of tearing down the differential and I have already ordered new bearings and gears. I’m going to reuse the carrier and just have a machine shop hot tank all the components and rinse them. It’s already taken apart. I have a question when it comes to assembly. I know that the lower pinion bearing has a shim underneath and between the lower and upper pinion bearings, there is a spacer with more shims. I also know that those spacer stacks may need to be adjusted in order to get the perfect bearing fit/pinion depth in the new setup. Should I keep the older bearings and shave off some inner material so that they slip on the new pinion easily in order to be able to mock up the assembly(possibly multiple times) and find the right shim stacks on the new pinion? My issue with this is that there might be manufacturing differences between the old and new bearings to the point where once I find the perfect shim stacks with the old bearings and then have the new bearings pressed on, it’ll be off. Instead, should I shave off material from the new bearings so that they slip on easily and then I can determine shim stack. I don’t like the thought of doing that to new bearings but I’ve heard other recommend that. The last option would be to just continue to press on and take off the new bearings without removing material but I feel like that will do damage and weaken them. I’m just looking for opinions on which of the three options is best. Thank you all!
 
You must log in or register to reply here.
-

Back
Top