Was able to snag a new outer axle stub to replace that crusted rusted mess that was in the driver side. Cleaned up the axles and painted them dark gray rustoleum for corrosion protection and installed the new joint. Went to work with the nibbler on the rusty knuckle, then used corroseal and flat black rustoleum. I didn't do much with the wheelhub other than some corroseal, might be replacing that - but not sure yet. I bought some 3/4 vinyl tube and shoved it in my shopvac along with a piece of towel so I could clean out that axle tube - lots of dirt/rust that I didn't want to push into the seal and diff. Pics for you amusement...

Started on the right side, and there is absolutely nothing wrong with the axle joint in that setup. I'll clean them up just the same though, probably won't replace the ujoint though. I fully expect to have the same issue that I was trying to address with this work... oh well, it looks a heck of a lot better now - and its one item removed in the process of elimination to finding my the problem... I'm wondering if its as simple as an alignment.

 

I don't get why you needed the towel...lol

 

To seal the small vinyl tubing to the large plastic shopvac tube, otherwise the suction... sucks :-)

 

Oh ok got ya

 

Got it all back together and tested it out, problem still there.

So I decided to make sure the CAD is getting vacuum, got out the vacuum gauge and measured about 16.5 at the frame rail right above the CAD. So not a vac source issue. Then I grabbed my vacuum pump, and tried to pull a vacuum on the CAD motor at the same point in the lines. There seems to be a small pin hole leak, as the vacuum will pull up but will not hold steady. My $ is on the vacuum motor housing have a tiny pin hole from rust. Have to go get that part and swap it out.

I figure I can run the passenger side up on a ramp to minimize fluid loss when I pull that vac pump housing off. Any other ideas to minimize that fluid loss?

Thanks!

 

I didn't lose very much when I pulled mine..... careful though, the bolts like to break. Hit 'em with chems for a few days before trying.

 

I got the bolts loose and ready, combination of Kroil and tapping with a small hammer. I'll get back to it later this week. I saw a big bubble of rust that is probably my leak on that vac cap.

Anyone have part numbers for the sheet steel guards and loom stuff? All that stuff on mine is about vaporized. I like to replace that stuff when its available.

Thanks!

 

Big bubble of rust on the end of the vac motor was my pinhole leak, holding my finger over it kept it from leaking down with the vac pump... The replacement Dorman fit TIGHT in the original housing. I checked that it would work once in its housing with my vac pump, and then I reinstalled it. Made sure it was in 2wd and put the truck in reverse with the wheels slightly turned... same noise, no change...

I am repairing issues, just not the one that is causing this noise. I did note that the 4x4 indicator does not light up anymore, so either the Dorman unit wants more vac than I have (16.5), or by messing with the housing hosed up the switch... I'll have to revisit that housing/switch to resolve - but that is minor compared to this binding noise.

I'm going to have someone else drive it in reverse and I'm going to try to see if I can pinpoint the sound area from outside the truck.

So the noise only happens when the truck is on the ground, running, and the front wheels are not straight ahead. I cannot duplicate the sound with the front axle off the ground and turning the wheels by hand. The only thing left are the carrier bearings or the spider gears in the front axle. I'm unsure why I cannot duplicate it with the weight off the wheels. I can feel the vibration in the steering wheel, so I do not think its the LSD in the rear axle. I don't think that anything else could be in play, given the trigger is moving with the front wheels not straight ahead. Frustrating me a bit... but I am committed to resurrect this thing, and the changes I've made so far were necessary - just not solving the noise I'm going after.

I'm open to new theories....

 

How's the fluid in the front diff look? Is it full?? If you ONLY get the noise when the wheels are turned, I would pull that front cover, and see what's up. Trouble is, in 2wd, the spider gears are turning anyway. The drivers side tire is always connected to the diff, so, in 2wd, the axle will actually drive the spiders, and spin the inner, passenger side axle.... or the drive shaft, or a bit of both.

 

I pulled both rear axle and front axle covers when I got the truck. I let it sit for a few months empty (didn't have the lube on hand and got busy with other stuff). So the fluid is brand new Mobil Syn LS, and there is plenty in there - I checked both front and rear before I went the ujoint path.

Truck was fine when I parked it, I would have noticed that noise just putting it into the storage slot in my driveway.