Picked up a low milage 92 K1500 from down south. Needed a trans rebuild. I got the trans apart and the new syncros and bearings installed and had a local shop assemble the case and give it a good cleaning. I put it in and seem to not have 4th gear.(pops out) I cannot find a good diagram for the 4x4 version of this transmission. Does anyone know if a shim or something goes behind the bearing retainer? Seems theres something missing and it's just pushing on the input shaft instead of actually going into 4th. Any tips would be appreciated.