When these trannys start to whine, particularly in all gears but 4th... it means your input bearing is dying.

If you plan on rebuilding... When you drop the tranny, assess how much play you have in everything, particularly the input shaft. I drove the crap out of mine to the point that it didn't want to shift gears. It got damaged to the point of being considered unrebuildable. Also, if your still driving on this tranny, check and change your tranny fluid, as input shaft play can cause gear oil to seep past the front seal. Running low on fluid will only further damage things.

Regarding rebuilding... I've read that most consider this a fairly standard rebuild. However, a lot of bolts/phillips tend to be stuck and will strip. Be prepared. Also, static electricity causes 5th gear to sometimes gets pitted. Never would have guessed. Make sure its still usable and when done put a few ground strapps all over the tranny to the body and motor. Use a gl4 spec fluid only for proper syncro function on a fresh build, not a gl5 back speced gear oil. Napa Stalube gl4 for conventional, or Redline MT-85 for synth, Lastly, someone here was selling strengthening pans for these trannys. Well worth the money to protect your investment.

Parts? I'd say call Kormex Transmissions of California. They sell kits and complete rebuilds. I got a full rebuild from them shipped cross country, and I didn't return my core. Cost $750. Heads up, there is a KM145-1, KM145-8, and KM145-9 (I think I got that right) so make sure to be careful you address this with your chosen supplier and get the right parts.

Best info on rebuilding and assessing would be in the starquest world. Look into Professor Quest's SOS manuals. It's all for starions, but the KM132 and KM145, minus torque tube/transfer case, are essentially the same animal.