99 Silverado trans problem

hello everyone,thanks for taking the time.i'll try to keep it short.99 silverado 5.3L/106k 4 wh 1500 series.son n law down the road possibilties
anyway he was having rear trouble ck out was told a gear or bearing
bad ok to drive till get parts?????no it was'nt blew the rear.after replacing rear w/used w/100k there is a vibration that gets worse w/speed from rear of car(can be felt in seat back)& there is no drive unless you manually up shift then trans shifts properly up/down until you stop.
i'm thinking maybe a balance issue w/drive shaft for the vibration but
dont no about the no drive problem.Thanks Again Mike
BTW after the rear locked up he put it in 4 wh & i guess dragged the rear???a couple of miles!!!!!

The vibration sounds like U may have changed the pinion to drive shaft angle...is the replacement rear axle centered and properly located on the pins under the leaf springs? Just a WAG here, but if the vibe started after the rear axle was replaced, I'd go back and inspect all the work that was just done.

As for the trans...can u explain with a little more detail? U say there is no drive?...meaning when U first start off from a stop and the trans range is in D1 or OD1, does the truck move? And then it moves if U manually move the shifter to manual 1/lo and manually up shift for each gear? If that is the condition, most likely the sprag in the input hsng failed.

hello everyone,thanks for taking the time.i'll try to keep it short.99 silverado 5.3L/106k 4 wh 1500 series.son n law down the road possibilties
anyway he was having rear trouble ck out was told a gear or bearing
bad ok to drive till get parts?????no it was'nt blew the rear.after replacing rear w/used w/100k there is a vibration that gets worse w/speed from rear of car(can be felt in seat back)& there is no drive unless you manually up shift then trans shifts properly up/down until you stop.
i'm thinking maybe a balance issue w/drive shaft for the vibration but
dont no about the no drive problem.Thanks Again Mike
BTW after the rear locked up he put it in 4 wh & i guess dragged the rear???a couple of miles!!!!!

sounds like the rear diff is in need of pinion bearing or sleeve wear...

transmission has no up shift ? I would check for DTC of drive train to determne why...

does this vehicle get regular maintenance`,,,sounds like not..
transfercase/transmission/rear diff need frequent servicing...also no operation of the 4X4 on solid dry pavement...

hello everyone,thanks for taking the time.i'll try to keep it short.99 silverado 5.3L/106k 4 wh 1500 series.son n law down the road possibilties
anyway he was having rear trouble ck out was told a gear or bearing
bad ok to drive till get parts?????no it was'nt blew the rear.after replacing rear w/used w/100k there is a vibration that gets worse w/speed from rear of car(can be felt in seat back)& there is no drive unless you manually up shift then trans shifts properly up/down until you stop.
i'm thinking maybe a balance issue w/drive shaft for the vibration but
dont no about the no drive problem.Thanks Again Mike
BTW after the rear locked up he put it in 4 wh & i guess dragged the rear???a couple of miles!!!!!

I just had my tranny replaced and had a similar vibration. I took it back to the mechanic and we saw that the rear u-joint has 2 clips on them to properly center the drive shaft into the rear pinion. My clip was rusted away and when put back in, the driveshaft was about 1/8" inch off center. We added a new clip to the u-joint and all is good again.

Check that first. Hopefully that is it. Post what you found. Later