th400 shifting problems

My g/f loves my truck when it dirty and begs to drive it... and she made me build her a truck so she can come along also.  

The wife rolled my first one for me on the highway. Her car was in the shop and she borrowed my '77 K5 to go to work. She calls me at about 6:00 am and tells me " You best get your but over here, your truck's upside down!" - Nice wake up call, to say the least. Some lady in a luxury car tried to make a left turn right in front of her, clipped the left bumber on my K5 and it caugt an "island' on the turn lane and flipped twice. The wife was ok, with just a seatbelt burn on the shoulder. K5's are the best! If she had been in something else she might not have made it. ( No roll bar in it either) ...so she was able to kick out the windshield which was just hanging there, and crawl out with the help of a Publix truck driver who stopped to help when he saw what happened. I was glad she was ok.  F**k the truck! ....but that was almost the end of my 4x4 days. She hated getting into any truck after that ordeal. I sold the truck for scrap after salvaging 2-1/2 rims and 3 tires. ( It hit pretty hard and made D rings out of two rims. It snapped the steering column when it hit. I can's say enough about how tough these trucks are after taking such a hard hit. All te damage was just rounding the corners on the front of the cab, but otherwise a fair salvage job for someone - 350 w NP205 D44 front & 12-bolt rear.

Good luck with your build! Sorry about hi-jacking your thread & goin off-topic there.

I'd go with what redbeast said, I'd either repair or rebuild the TH-400. I would not even think about the 700r4 trans. as they are junk transmissions. As for exchanging it for a rebuilt one, never ever go to AAMCO as redbeast said. He didn't acually say this but I know what business he's talking about. I don't know how this place stays in business!  

not a wife. But today I was going to wash my truck and she freaked out. She was outraged at the thought of washing it. I told her to calm down and that the mud could stay. lol great stuff. go figure the one thing I enjoy keeping clean and well kept I'm not allowed to either.  

You must be psycho!! (psychic) .  I have no clue how they stay in business either. Midas muffler is no prize either from my experince. I took some warlock mufflers to have some reducers welded on the new mufflers (not on the truck yet) and they did such a bad mig welding job that I could have been drunk off my ass (not a welder) and done a much better job of it! Not only did they not grind the welds down, but they left inch long pieces of Mig wire sticking out of it. That's what drove me to buy a little Lincoln Mig welder and re-do the job myself. Been welding ever since. That was my first & last visit to Midas!

Women are a mytery to us all brother!!  I could not imagine a world without them though - they rule my world for sure.   Just when you think you have them figured out they pull something like that!  I think they do it just to *** with our minds!! 

My wife always gets a big thumbs up from guys who see her on the road driving my beast. The rest just look scared and stay out of her way!

I have gone through 3 of these trannies and it was because of the gearing I used which was 4.88 gears with 35" tires and I ended up burning the reaction carrier up because of the centrifugal force throwing the oil away from the planetaries. I do have this same set-up in a 1978 Blazer that is still running today and hasen't had any problems whatsoever. There is some years that you don't want to get of the 700R4. To get the best, look for ones in '86 or newer. There is the earlier '83 and '84 but they are junk unless you want to change the input shafts for they are smaller. Hope this helps those that don't know this.  

YZ250JV:
I have gone through 3 of these trannies and it was because of the gearing I used which was 4.88 gears with 35" tires and I ended up burning the reaction carrier up because of the centrifugal force throwing the oil away from the planetaries. I do have this same set-up in a 1978 Blazer that is still running today and hasen't had any problems whatsoever. There is some years that you don't want to get of the 700R4. To get the best, look for ones in '86 or newer. There is the earlier '83 and '84 but they are junk unless you want to change the input shafts for they are smaller. Hope this helps those that don't know this.

Never heard of a tranny burning up from too deep of gears. I think you had other issues causing it and not the gears. Also, on the 700R4, the early ones had a 27 spline input shaft vs later ones having a 30 spline but the problem is not the input shaft, it is the internal design of the tranny itself which was changed when input shaft was changed too. The 27 vs 30 spline input shaft is used to tell revision of tranny in a bone yard, not the strength of input shaft. 700R4 were pretty solid 85 and one and with the last tweak done to it in 87 and it remained unchanged until 93 when the valve body was upgraded to a electronically controlled one and it was renamed a 4L60.