TH350 noises, are my suspicions correct ?

[mtnmankev]

83 C20 with TH350 non lockup trans.
Previous owner had it rebuilt long before I bought the truck.
It shifts fine, doesn't slip and the fluid is not burnt.
However, recently it started making whirring and whining sounds as soon as the engine starts and the innards begin to spin in the tranny.
I suspect the rebuild was a quickie job and they did not replace the bushings or sprags.
I think whoever did it was slip shod at best, as they also left out the bolts holding the tailhousing to the rear mount, and I keep discovering stripped out bolt holes i need to helicoil.
I am on the fence about rebuilding this one, or buy one from a wrecking yard and hope it's in better shape to build.
Any tips and advice on a rebuild would be greatly appreciated, as i only want to do this job once, and cannot afford to pay a shop (even if there was a shop I could trust, which there isn't).

 

[Jason Deckard]

If you have some bolts that need helicoils, then just get you another trans case. You want to use new bushings everywhere. Good luck finding a good 350 case. I bought 20 of them from a salvage yard about 15 years ago and have went through most of them. Let me know if you need any parts. I have a pretty extensive inventory. Get some good friction plates and soak them I'm transmission fluid for a few hours before assembly. A 350 is very easy to rebuild but a few special tools are necassary . Let me know if you need help.

 

[mtnmankev]

Thank you for your reply and offer of advice and help.
I may just end up taking you up on the offer !!
I did some research, and it points to the torque converter making the whirring noises.
The tranny shifts fine, does not slip, fluid is NOT burnt, and the pan was very clean and almost zero traces of debris when I changed the filter recently.
I need to yank the engine to replace the rear main seal, the oil leak is driving me nuts and that's the easiest way to do it, so I plan to install a new torque converter at that time.
If the noises go away, I will run the tranny until something fails.
If it keeps making the noises, then I will order a rebuild kit with sprags and bushings and do a complete overhaul.

 

[78C10BigTen]

Too bad your in AZ, i have 2- th350s that need rebuilt i coulda sold you one.