Hi :)
Well, all of you knows, for sure, that it's cold in Russia and, sometimes, there are bears walking on the streets :)
Last days the weather is more and more cold - it's 0 deg. C. outside now and i have a strange problems with my TH-350.
If the car was sitting on the parking lot for all night long, when i start the car and put the tranny in "drive" in engages fine... But on the first (or may be two) stoplights seems just like it kicks from "drive" to "neutral", than, after a second or two it engages again...
After warm-up it is working great - no noise, slipping;shifts firmly right in time.
Also, it works fine at warm weather...
The fluid level is fine, the fluid is brand new D-III, filter was changed 2000 miles ago.

What's happening with my tranny ?

This is a common problem. The hydraulic seals (clutch piston seals) get hard and lose their ability to hold pressure as the tranny gets old and the rubber seals harden. As the fluid warms up, the seals get warm, become a little softer, and start to hold pressure again. Unfortunately, the only way to fix it is a complete disassembly & rebuild. Usually reverse acts up before the forward gears on a 350 because the piston seals are o-ring type seals as opposed to lip seals on the forward gears.

If you have a pocket full of money go ahead & rebuild it and your problems will be cured. A temporary fix would be to pour in some trans additive. A little wont hurt anything. This will soften the seals temporarily and probably get you through the winter. I doubt you will have any problems during warmer weather. If this gets you throught the winter you will need to think about a rebuild before the next cold season.

I have the same problem with my '87 Mustang with AOD, and thats the first time I have heard the seals are hard (I've heard just about everything else), I think I have to agree with that answer! I didn't think of them. I live on a dead end street and the only way out is up hill! I have to let it warm up, or not stop for the stop sign at the top. :( Only when it's cold out, It's been doing it for over 2 years that way ,and I drove it from Fl to Mn. now I have to drive it to Tn that way, and then fix it there. We drive it every day.

I don't like addtives in my trannies. Someone told me to add Lucas to my Blazer for a smoother, firmer shifts, now I don't have drive or overdrive and no time to fix it!

Pat

Sorry to hear about your Blazer. Obviously it's a 700 tranny. If you lost 4th gear it should not have been the result of a trans additive. More than likely your 3-4 clutches gave up the ghost. Pretty common on older 700's especially. The additive we spoke about probably has some slippery teflon type stuff in it to make the valves move better and it definitely has stuff in it to swell/soften the seals. Like I said, a little wont hurt (follow manufacturers directions). Sometimes people get carried away and add a lot. This can swell the seals so much they become weak and disintegrate. A pretty cool experiment is to take a rubber o-ring and put it in either brake fluid (the old stuff prior to Dot 3), or in laquer thinner. After a few hours it will swell like crazy. These chemicals are what unscrupulous folks would use back in the day.
Mike