I have a 81 chevy half ton 4x4 and have swaped in all the drivetrain form a 87 1 ton, th400 np205 14ff and a dana60. The problem i am having is that when the transfercase is in 4Hi it shifts perfectly fine but when i put it in 2Hi the transmission wont shift out of first gear. I am completely stumped on this and it is my daily driver so i would prefer not to drive around eveywhere in 4. Any help would be greatly appreciated.

Thanx!!!!!

ray, i have a 83 chevy and i had to replace the clutch pads. its not that expensive and your tranny will be almost new. or the kickdown cable might be stuck in the up position. you will find it on the passanger side of the transmission and it will run up to your carb where ur throttle cable and maby cc if you have it. its an easy fix if ur exhaust is out of the way but mine was a pain bc the exhaust was right in teh way. so we had to drop the tranny. not bad seein it wasent hooked up yet. any ? email at scubadvr1999 at hotmail  

check to make sure you are not pinching off the vaccum hose when you shift from 4 high to 2 wheel. the trans needs vaccum to shift.  

Hey thanks for the ideas guys. It turns out it was because my old tranny had a lockup torque converter and i pluged it into the same clip on the 400 but the connection there is for the electronic throtle position and for some reason it caused it to not shift so i took it off and now she works great. thanx.  

Hey, I'm glad it seems to be working O.K. now, but there are two things you need to know. First, the vacuum hose goes to the modulator, that is what controls your line pressure in the trans, very important, by the way you might want to get an adjustable one, they are only about 15-25 bucks, and you can dial it in to exactly how hard you want it to shift..

The other is the only electrical connection on a TH400 is for the kickdown (downshift) solenoid. There is no lockup on a TH400, at least not from the factory. (Yes I know some will say, well my trans has one. But it is still not a true lock-up converter) Also as I'm sure you know, since you put it in yourself, there is no kickdown cable for a TH400, thats only on TH350, TH200 and 250Rs, and on 700R4s it contols downshifts and line pressure.

I don't know exactly where you plugged it in up top, but unless it was off of somewhere by the throttle, it won't downshift properly and will burn up the trans. If it was up top and downshifts well, then don't worry about this post!

Just givin info, good luck.

G.M. trans-man

Hey there, what would it take to swap a 700R4 into my 81 chev 3/4 ton
350, TH400, NP 208?

Is it a strait swap or do I need a different cross member?

I 'm lookin at the 700R4 for the overdrive.

better hope that 700r4 tranny has been built up to handle it.  they are by far the weakest tranny chevy ever put out.  with proper mods and someone that knows what he is doing it can be built to handle any power you want to put to it.

I was waitin form somebody to say it! Id stay with the TH-400 and either swap it out for another at a reputable transmission shop ( not the shop name that immedately comes to mind for most folks ) (rebuilt with a core trade), or fix the headaches on the one he's got, and beef it up.

After a little reseach and advice I think I'm gonna stick with my TH400, the one in my beast is solid, I sure miss the overdrive though and so does my wallet. Running 35's and 4:11 gears dont help.

Cheers

4 11's and 35's is actually preety tall... a 700r4 w/ a 350 wouldn't be overloading it as longs as its not to pumped up. Another option would a 4l80e w/ stand alone computer, but that is getting pricey, wouldnt sacrifice any strength though

Ya I read an article about a build up on 700R4 making it super strong with a full lock torque converter for desent and all that, it sounded really good, but it is way more than I'm willing to spend, I'll pay for the gas. It's just a bush beast so it only see's the dirt on the weekend play time.  

You can't have 'Mr. Hyde' and 'Dr Jekyl' too!  That would be a perfect world, and sadly, we don't live in one. Let nature have it's way. The beasts rule!! - unless you live in the city, and have to trailer to the beast's natural environment. 

... in this case the 4l80e is the best of both worlds, ultimate strenth with an overdrive, or am I missing something. A little work will need to be done to make it work right, but it is worth the work.  

If his wife is anything like mine he'll be hearin the music from her if he goes the expensive route on this build. "You spent how much on that truck ??!!" Wives just don't understand the what a deafening roar from the engine, and a deep growl from the exhaust does to a man. - Be still my heart!!  I get dirty looks from all the old folks, some of the women, and thumbs up from all the guys and the kids in my neighborhood when I take 'the beast' for a walk.

Ha ha.........too funny, my wife hates my bush beast with a passion, to the point she refuses to drive it, she doesn't understand or appreciate the strength or the ability to drive over large things, she would much rather drive my 95 Z71 that "rides like butter" as she say's it.

Does anybody have a wife that likes a huge dirty 4 x 4?

I think that a 4L80E may be in the works for the beast real soon, seems the better option, I'll keep an eye out in the wreckers yard for one to build, I think I'll wait ill the 400 starts to go.

Cheers