"dragging" rear wheel

[dyeager535]

Kind of an interesting problem (just one more I get to solve lol) that I noticed with my new-to-me 14SF that I installed.

Already replaced the gov-lock carrier (thanks Rene!) as the old one had busted teeth in the mechanism. Now I'm thinking perhaps I know why...

Brakes seem to be good, (pads ok, nothing broken) replaced the wheel cylinders and brake lines, and took the thing out for a spin. Decided to do a u-turn where the rear was off the pavement. Heard a dragging sound, looked out my window, the drivers rear wheel was locked up. It just unlocked by itself after a second, (maybe because I straightened up or increased input to the rear end) and I spent some time trying to replicate the conditions.

It started doing it on the pavement as well, but not consistently. If I apply the brakes fairly hard, the rear wheel(s? can't see both) lock up for a split second, hear/feel a clunk, then act normal. Truck doesn't really pull too much, but does more than it ever has. I'm in a neighborhood, so I'm only going 25-ish though. Certainly feels like the rear is what is doing the pulling to one side, but just a hair, probably due to the slow speeds.

I popped the wheel/drum off on both sides, and neither show any real damage or obvious problems. Well, the PO DID install the star adjuster backwards, so it hit the spring that runs there, so he decided to cut the teeth off of most of the star wheel. It's more like a rectangle adjuster now. Ok, so maybe it's KIND of broken, but just slightly lol.

Since the "leg" that hits the adjuster wheel is not making contact, I adjusted to decrease pad contact with the drum, just to test. Didn't seem to make any difference. When I pulled the drum the first time, it was no tighter than normal, so it doesn't appear the adjuster is just spinning open to increase pad contact.

I definitely need to replace that adjuster, but even with it replaced, I can't see why that would be the cause of the binding. I compared both sides, both appear to be set up correctly, (now) and the e-brake works fine.

It only drags when I'm turning left, if it were the gov-lock, I'd be inclined to think it would happen either direction.

Anyone ever experienced something like this before? Any input on the adjuster being culprit or not? If I can find a truck not buried up to the axle at the wrecking yard, I plan to replace that adjuster Friday, but won't be able to drive/test it for awhile.

 

[pauly383]

Since this works on wheel speed ( gov loc ) , perhaps check that wheels diameters are real close . Different size tires mean different wheel speeds . You can adjust a little by air pressure .

I remember my 10 bolt gov loc would do the passenger side wheel sometimes , before it blew up .

I never remembered any noise , clunks , or issues the first year or so . But with wheeling and driving it daily , I got clunks and noise later . Thought it was normal and it wasn't .



You made sure nothing pulls on the e-brake cable during suspension cycling ?

 

[dyeager535]

Everything was pretty much a "drop in" for the 10 bolt that was there, as much as can be. E-brake lines are clear of anything, and if the problem had to do with suspension cycling, I'd expect it to clear up after weight transfer, which it doesn't do. It seems like it "unlocks" about as randomly as it locks.

My 10 bolt gov-lock didn't do this, and these are the same wheels/tires as before, and as a matter of fact, I checked tire pressure before this happened, and just the other day, to make sure they are the same as they have been, which they are.

After the condition of the gov-lock that came in this axle, I made sure the "new" one was in good shape, and it is. There isn't a loose/worn part on it. As a matter of fact, the carrier I replaced appeared to be a service/aftermarket install, as it was just too new and clean for the way the rest of the housing looks. I suspect now that whatever caused it to strip teeth had to do with the problem I'm seeing now.

 

[diesel4me]

hmmmm....

My 82K20 feels like a brake is dragging in the rear sometimes,and I have to apply a bit of throttle before it "breaks loose" and then it seems to turn freely--I took off the drums,and no rust or other problems,and the brakes are not adjusted too tight!..I'm hoping its not a gov-lok ready to peuke!(never had the diff cover off).the fluid is up to the correct level,and looks ok--.maybe someone welded the spider gears?? or maybe a wheel bearing is seizing up(but no noise!?) ...I'm almost afraid to look!..

I kinda wish I kept the rusted 14 bolt SF out of my 74 k20 ..If you find your problem,let me know,because it sounds just like what my truck is doing!..once your underway,the rear end is quiet,no noises..but parking or backing up,it feels like the brakes are dragging!.(not all the time though--maybe a posi clutch sticking?)..I doubt its the rear brakes,because the master cylinder is junk in the rear section,all the fluid leaks out the rear of it,so the rear shoes probably dont even move!(have to get another master cylinder!)...

Anyone know if the master cylinder off my 74 K20 with vacuum assist would fit the hydroboost system on my 82 diesel??--they look the same...

 

[dyeager535]

Going to try and get my hands on the brake parts tomorrow, I'll update as I make progress.

 

[dyeager535]

Pulled the drums back off today, after getting a pair of shoes for replacement.

Upon close inspection, a previous owner that shouldn't have been doing any mechanical work had obviously messed around with the brakes. Miscellaneous springs were hooked up wrong, or the wrong ones were used, so back to the store for a parts kit.

Put them all back together with the new shoes, no locking up rear tire (both will if I stomp on it) and good pedal feel, so I say it was a success.

Of course, the rear is still locking up randomly somehow, but that has to be the gov-lock for whatever reason. It will eventually break if it keeps that up on the street I suspect.