ETOD of my tranny?

[jdwhitlo]

I need help "estimating time of death" for my Transmission. 72 GMC C20 350/TH400.

I am assuming It's the TH400 but I do not know that for sure. The guy I bought it from said that the tranny had been replaced about 30K miles ago but he didn't think it was the same as original. I wasn't very concerned about it because I have plans to do a 700R4 conversion this summer. But I recently moved to Colorado and in this cold weather it has gotten worse and I'm not sure it will survive till summer.

Symptoms:

1.) When cold it will not want to engage into gear. Reverse is the worst.
2.) When cold but having gone into gear and moving it will shift but will take a very long time to engage into the next gear. Acts as if it were a manual that you were burning the clutch in.
3.) Still cold, and I come to a stop it will shift in and out of drive and neutral causing the truck to jerk. You can hear the idle of the engine start to gradually rise then it jumps hard into gear. It will do this until it gets wormed up.
4.) Once wormed up all symptoms go away and the tranny works perfectly.

I would assume it's either the torque converter or the clutches but I haven't dealt with many transmission issues so I'm not sure.
I have checked fluid levels and all is well. It does not leak fluid either.
I would like to know if anyone has experienced this and if there is a low cost fix? If not, how long do you think it might last?

[WorkinLonghorn]

Doesn't sound too good really,especially the part about it acting like a manual that you where burning the clutch in.
If it was me,and I was a cheap-charley (I am) I would make darn sure the thing was well warmed up before I drove.(Actually I wouldn't even drive it!) I might even try some of that magic "seal softener" addative as a last resort(good luck).But first I'd change the filter,see below.
I would imagine that the fluid is dark and has a burnt smell?
One thing;The th400 (the pan is irregular in shape,the TH 350 looks square with one corner cut off) has an actual filter (instead of a sceen on the 350) and it WILL clog up on a transmission that has a lot of friction material etc. that has come out from above.If you remove the pan and replace this filter there is a slim chance that you can keep using the trans through the spring.But NOT NOT NOT if you are driving it aroung with the clutches/bands slipping away!

[jdwhitlo]

I checked and I have the TH350... Going from what you said it sounds like I'm SOL.... I don't drive it very much at the moment so maybe I can get it to survive. I'm looking for another vehicle so when that happens I'll just do the 700r4 swap. Thanks for your input!