picked up a truck on a swap, curious if this is the rear end or the transmission thats causing the problem?

Forward gears work fine, when using reverse, 1 out of 5 times the truck will slam to a halt after backing up a few feet. It appears that its one tire more than the other, in this case the drivers rear.

All I am concerned about is, is this the rear end, transmission, or the emergency brake locking up? It's got me puzzled.

 

It sounds like the ABS hydraulic unit has a solenoid or valve hanging up that is causing the one rear brake to lock up by preventing its release due to stuck solenoid or valve. The only solution for this is to replace the hydraulic unit. The usual cause of this is not opening the bleeder screw for the calipers before retracting the piston. By not opening the bleeder, the fluid is pushed back towards the ABS unit and master cylinder at too much force and damaging the ABS unit in the process.

 

wow, its a darned good thing I asked because I never would have guessed that in a million years! Now, where is it located...because I have never heard of one?

And thanks a ton!

 

do you hear any growling noises or loud humming noises at highway speed? I was thinking rear axle bearings or rear diff issues.

 

It came with some big non road tires on it and haven't had it on the road at all. The most I have driven it is on my driveway and back and forth.

 

The ABS answer is a far fetched GUESS and an expensive one at that. I have never seen or heard of the ABS causing anything even close to this description. Unfortunately you are going to need to take it to someone experienced to at least feel / hear the problem to point you in the correct direction. This is not something you are going to find an answer for on a forum. It must be experienced by someone. Everyone describes things differently. The trans, diff or transfer case could easily be the cause.

 

I appreciate all the answers guys, I know its tough to figure some of these issues out online.

I got around to swapping the super swampers off and putting some LT tires back on and took it for a run up and down the road, getting up to highway speeds for a few miles at a time, and didnt hear any unusual noises at all.

I did notice that the brake light is on on the dash and that the pedal is spongy going both front and back. It actually felt pretty soft going both forward and backing up...

This is a full time snow plow truck for me, or will be, its not a daily driver, so I will add that yes, it is more important to me to correctly diagnose the problem, rather than throw parts at it, hoping one of them fixes the problem. Where I am at we get enough snow that I need to be able to depend on my plow truck 100%.

 

Update:

What I am experiencing is this: I put the 97 Silverado 350 / automatic transmission in reverse and every other, every 3, 4, 5 times I do that, it will at some point lock up one of the rear tires and slam to a halt. It is not something that the other wheel then takes over and it can drive in reverse, it is dead in the water stopped.

I then put it in forward, drive forward a bit, put it in reverse and sometimes it allows me to back up with no issues, other times it will slam to a halt, locking up the one rear tire/wheel.

There is no uniformity or pattern other than it happens in reverse.

 

I am currently having the exact same problem you described with this post with my 96 Chevy 1500. Did you ever figure out what was causing it? I'm sure it's probably what's wrong with mine and would greatly appreciate any information you found out.