rear Differential issues?
 

Hi All,
I inherited an old 88 s-10 blazer with a plow. Used only for plowing so not too worried if I need to part it out.... Here is the issue. it moves well in reverse in 2wd and 4x4. However when trying to drive forward the rear wheels seem locked almost as if the brakes are locked on. But pretty sure it is not the brakes as it rolls fine when in neutral. So I am concerned that it may be the rear differential. This is not road worthy so I am trying to decide if I should keep putting $$ into it as a plow truck as that would be really useful with my long driveway. I'm not very familair with 4wd trucks so im not sure where to concentrate my efforts..

any ideas would be appreciated!!
Thanks all....

its possible one of the bearings on the carrier fell apart, ive seen what your describing a few times. basically when you go one way the carrier is pulling away a bit from the pinion allowing the truck to drive but when you torque the rear end the other way it goes into the pinion locking up the differential. best way would be to pull the cover off and see if theres a bunch of metal chunks all over the place. or check the brakes anyways. possible that a pad came loose and only locks up going forward

im sure you could find a junkyard rear end for cheap and change out in a day if you want to keep the thing