hope someone can give me a little help here, i have a 1990 s15 jimmy and today on my way to work the truck suddenly clunked and started making a clicking noise ( similar noise to when a vehicle is put into park while still moving) i was able to limp to work but now reverse does not work and it still clicks. Thanks in advance for the help!

 

Also i can move the vehicle while it is in park?????

 

when my transmission blew...I first noticed it when I went to step on the gas and it didn't go anywhere...so I let up...it ran ok as long as you didn't try to speed up to fast..otherwise the gears would just not engage...I lost my reverse....I could push it...even still drove it to the dealership.......so chances are you will need a new transmission.....but the other people on here no more..I just know from my own experience....

 

Me thinks its time for a rebuild of the tranny. the SUn SHell( reverse gear is notorious for gng bad. just my two cents

 

I think Hillbilly got it right.
Sounds like you blew out the Reaction Sun Shell. When they go out it sounds like a whine, no reverse, no 2nd gear, and no 4th gear. If you manage to drive it (limp) it won't want to shift into 2nd gear and if your going fast enough it will eventually shift into 3rd gear.

I posted a thread on mine. You could just replace teh REaction Sun Shell, however the tranny has to come out, and it has to come apart. Since your to this point, a rebuild isn't too out of reach at this point. When you get it rebuilt or replace the sun shell. Make sure and request a heat treated sun shell. My tranny parts store only carries the heat treated units, others might carry the OEM original too. This is one time I would avoid the GM original, unless the dealer can verify it has been heat treated.