hey everyone, im new to the mini truck world! I just picked up a 1991 sp83 hijet ..It has been sitting for a while! But I have it running now! When I picked the truck up the rear right tire wasn’t spinning...when I winched it on my trailer! Got it home and the tire was freed up and rolled it right off the trailer! But now it’s locked again! Iv got the truck running so this is my next problem! I can put the truck in reverse and back up about a foot then the back tires lock up! Same thing when I go forward!! Any ideas?
If the other wheel is OK, then it is hopefully just a problem with the brake shoes, or at worst a heel bearing
Pull the diff cover. Half a rotation in either direction sounds like a broken cross pin hanging out of the carrier and hitting the axle housing to me. Jack up the rear and see what each of the three items will do. if tires spin free opposite of each other but driveshaft can't go around and around, that confirms differential issue.
Thank you for the reply! When I jack it up the tires will still lock up but the left one will make more of a rotation! Tires do spin the opposite way!! At work now haven’t gotten a chance to pull diff cover off!
Thanks everyone! I figured out the problem! Pulled the tires off and and the break pads had it in a bind! Figured it out one side at a time! Pulled the drum off and the pads fell out! Rear right tire was freed instantly! Then checked the left side to see if it would spin while I had it on jacks!!! But it would rotate as much as you would wanted backwards. But forwards it wouldn’t spin much about a 1/4 rotation...Surprised the crap out of me!
on many diffs the cross pin will clear the ring gear, on some it will not. There should always be a roll pin or bolt that holds the cross pin in place. Even if it doesn't clear the ring gear, it can still hit the head of the pinion and stop the case from rotating in the housing. I'm glad that wasn't the issue here, brakes are much easier to deal with than a broken cross pin and the carnage that can create!
