grinding noise with hubs locked

[bigghoss]

I have an '84 k5 with a dana44 front axle. as I came to a stop at a stop light today I heard a grinding noise which at first I thought was the brakes even though I replaced the pads not long ago. the next light I went very easy on the brakes and I didn't hear the noise. I pulled into an empty parking lot and tried stopping hard and easy and it didn't make the noise when stopping slow and easy. being winter I had the hubs locked but when this started I had it in 2HI not 4wd. so I unlocked the hubs and the grinding went away completely. my driver side hub for some reason is loose and leaks grease but the screws are tight so I unlocked it but left the other locked and the noise came back but only slightly, so I did the opposite and it did the same thing so I doubt it's related to the bad hub. I thought it might be the front diff(open) but I thought if that was the case then it would be making the noise whenever I had the hubs locked, I guess it could still be I don't know.

bullet points:
-with hubs locked in 2wd under normal-hard braking there is a grinding noise
-light braking no noise
-hubs unlocked no noise
-one hub locked one unlocked noise returns but not nearly as bad and sounds more like a clicking

also as I mentioned my drivers side hub is loose and grease leaks out but the screws are tight but it does lock

 

[Stomis]

Sand in your hubs. Figure out where its leaking grease because where the grease is leaving dirt is getting in.

 

[lectric80]

You may want to check out the front driveline. Even with the hubs locked and the TC in 2hi, the front driveline turns because the differential is turning with the axles. On mine, I started hearing that noise and ignored it since it had no effect on anything important. Finally my slip yoke lost the splines and I pulled the driveline, found that the CV ball was flat spotted and causing the issue. To look at the driveline you couldn't see anything wrong, but when it came out you could see how the movement was not smooth the way it should be.

 

[6.2Blazer]

I would suggest the same thing. Check the u-joints in the front axle shafts and the driveshaft.

 

[bigghoss]

someone at work mentioned it might be the driveshaft as well. I'll check it out.

 

[86-1ton]

mine does the same thing, but i know i have a grenaded pass. hub... i heard it one day, and took it apart to find a broken plastic ring in it... i've got a D60, but could be similar issues...

also, i know i've got a weak'er' u-joint in it, it flexes a little bit, but i can pump grease in it every couple days and it won'f move...

couldn't tell you about the driveshaft... i haven't taken my front one out, but i do grease it alot... too much, probably (i grease everything with a fitting once a month), but at least it won't be starved...!

 

[Thunder]

Could also be a spindle bearing. They are located on the back of the spindle. Check the front axles at the steering knuckle. If you can rock the stub shaft around in the spindle the bearing is bad.

 

[bigghoss]

well as much as I didn't want to I was forced to drive it to work today because I couldn't find another car to drive while my blazer was in the shop. the hubs were unlocked and there was no noise like when I tested it before so I'm pretty confident so far that whatever it is is isolated to the front of the 4wd. fortunately I'm picking my other car that just got finished tomorrow so I can take the blazer in on monday. hope it doesn't snow or ice up!

 

[jonathon]

When mine did that with the hubs locked in, turned out to be the spring in the warn hub was messed up causing the lockouts to either partially engage or bounce in and out of engagement making a ratcheting type noise. Rebuild kit and about an hour total I had it as good as new..