Driving K20 without the rear driveshaft?

[MaverickH1]

I'm trying to trouble shoot a driveline intermittent groaning noise starting to get loud around 55-60 mph.

My plan was to remove the rear driveshaft, put it in 4wd, then essentially drive it as a front wheel drive vehicle at around 65 mph just to check if the noise went away. Hopefully the noise would go away and I'd be able to know that the problem is somewhere in the driveshaft.

I just pulled the driveshaft and a ton of fluid came out of the transfer case. Maybe a 2' diameter circle on the ground.

With that much fluid coming out, I'm a bit worried about driving it at all. There is a u-joint on the front of the driveshaft that isn't smooth in one direction. I'm thinking the problem might actually just be that u-joint. But it'd be nice to take it for a test drive first if it's not actually going to hurt anything. Curious what you guys think.

Cheers!

 

[SquareRoot]

So you want to drive it at 60 mph while pumping the remaining fluid past the unsealed output shaft?
Sounds like a great idea!
Please report back with pics

 

[Turbo4whl]

Here is what you do. Take a soda or beer can and cut the top off. Wipe off the drive housing, then take duct tape and wrap it around the housing and pull it off. Do this a few more times until the duct tape has pulled all the crud off the housing and the tape is now sticking well. Slid on the can and tape it tight to the housing.

Drove my 1985 Suburban over a 100 miles home on the front axle pulling my trailer.

 

[MaverickH1]

So you want to drive it at 60 mph while pumping the remaining fluid past the unsealed output shaft?
Sounds like a great idea!
Please report back with pics

I'm asking because I'm not sure. For example, I don't know if that rear seal on the transfer case is basically just a dust seal and no fluid was supposed to come out when removing the driveshaft. I thought MAYBE an internal seal beyond that had failed and had a lot of fluid where fluid shouldn't be. And if a slow internal leak was occurring, not a big deal to top off the transfer case and off I go.

Your answer lets me know in a snarky way that my assumption was incorrect and that the rear seal is actually a fluid seal.

I sure wish I had drained it first before pulling the shaft!

 

[MaverickH1]

Here is what you do. Take a soda or beer can and cut the top off. Wipe off the drive housing, then take duct tape and wrap it around the housing and pull it off. Do this a few more times until the duct tape has pulled all the crud off the housing and the tape is now sticking well. Slid on the can and tape it tight to the housing.

Drove my 1985 Suburban over a 100 miles home on the front axle pulling my trailer.

I'll see what I can do, there. Honestly leaning towards just replacing the known bad u-joint and seeing if that fixes everything.

That said... the u-joint is being a total PITA. Pressed it out on one side, removed the cover, starting trying to press it the other way and I guess it wasn't aligned perfectly and it shaved a little bit of metal off the driveshaft hole while I was trying to press it in. /sigh

Now it's like a cross threaded hole where I can't seem to get it started straight. I sure wish they had some kind of taper on u-joints caps to make them align better.

Has anyone come across the MOOG Heavy Duty u-joints just not being worth the squeeze? I'm unsure if these are just much larger in the body and thus much less clearance to remove/install between the driveshaft ears or what.

Starting to worry that I need to buy a new driveshaft, but can't even find out. Started looking at whether I could buy just the tip and slap the driveshaft on the lathe to cut the old u-joint connection off and weld a new one on, then take it to a mechanical balancing shop nearby. But... can't find any of the ends for sale either.

 

[SquareRoot]

I'm asking because I'm not sure. For example, I don't know if that rear seal on the transfer case is basically just a dust seal and no fluid was supposed to come out when removing the driveshaft. I thought MAYBE an internal seal beyond that had failed and had a lot of fluid where fluid shouldn't be. And if a slow internal leak was occurring, not a big deal to top off the transfer case and off I go.

Your answer lets me know in a snarky way that my assumption was incorrect and that the rear seal is actually a fluid seal.

I sure wish I had drained it first before pulling the shaft!

It is a fluid seal but the level of the fluid is below the seal. Whatever leaks out is just a portion of what gets "flung" into the rear housing area of the t-case. You would be ok to seal it with a bag and zipties for a short drive. I had a similar issue but I have a 205 with a fixed output rear yoke. In my case I just unbolt the shaft, disengage the rear output and drive in front wheel drive only. I did help me troubleshoot it. My issue was a bearing on the output shaft was not fully seated.