Transmission options

[mrscot83]

First of all I gotta say that I have read and learned alot from everyone in this forum - it's really cool to have access to this kind of resource.  So, thanks in advance.

  I have an `83 Chevy Scottsdale 2 wheel drive.  1976 350 with the original `83 carb.  The transmission is a 700R4 with the TV cable and all that stuff.

  I have never replaced an automatic transmission.  I was on the highway, I booted it to go into passing gear, except it slipped and clunked really hard.  The fluid came out of the dipstick and the vent.  I lost 4th gear and had to let off of the accelerator to get it to shift.  I think the torque converter caused the problems?
   I am looking for the best bang for the buck.  I read that the later the year tranny, the better they are.  I plan on getting a tranny from craigslist or a junkyard (with a 90 day warranty).  I don't have an ECM, so I need to find out what the cut-off year is and when GM started making changes for the better on the 700R4. 
   Also, is it worth it to switch to a TH350?  My guess is not...

[Lt.Del]

you could go th350, but you'd have to change the location of the crossmember under the tranny and you loose overdrive.  Stick with the 700r4.  Just when looking for another, avoid the first year of two.  They did get beefier a couple of years in.

You could get an ecm from a salvage yard and put in the best tranny out there... 4L80E. 

 

[mrscot83]

Thanks for the info.  I just saw a pretty good explanation on hotrod.com.  It seems that 82-83 700R4's were the not so reputable kind.  `84 started getting better with corvettes having the better shifting capability.  1988 seems to be the cutoff year for swapping without adding the ECM.  Does that sound right?

[team39763]

If you go with a 4L80E, you can get a manual shiftkit or manual valvebody(guy in Dallas working on one).  That way you have one of the toughest GM transmissions, still have overdrive, and won't need a ECM.  It may take some time to get used to shifting it, but if you're a "performance nut" you might like it.

[mrscot83]

I am a performance lover, but $$$$ is not my friend right now.  I just found out my 700R4 is a 1985...I think.  The code is 5YT   348H;   With a big MD8 on it.  Is that worth re-building?

[VileZambonie]

Where are you located? Find a good rebuilder.

[Captkaos]

I would get the one you have rebuilt.  Typically you want a 1987-1993 700R4 (4L60).  1993 is when the 4L60E came out and both electronic and non-electronic transmissions were availible.

[Jim Rockford]

yup , try and avoid anything under 86 (weak)and above 93 (full electronic) the 4L80E isn't an option without a $700 controller, or doing a complete later model engine swap,  you can't just (GET ) a ecm and hook it up, the ecm has to see what the engine is doing to make the decision on when to shift. plus then you have to figure out how to convert from electronic speedo signal to mechanical so you can have a working speedometer. time you get done laying out the cash for all that you could just have a nice beefy 700r4. and get a locking trans dipstick from a latermodel 700r4.

[mrscot83]

I opted to get my 85 rebuilt.  Just picked it up today.  The guy rebuilt it in 1 day for $500 cash.  He said the last re builder used a lot of silicone...I guess that's bad.  The bands were burning the drum and a clutch went out.  I'm on my way for a new mount, then the fun starts.  A guy told me to take 2) 3/8"  bolts, cut the head off and grind a slot in the ends.  Screw `em in and use for guides.  Start the bolts and remove the others with a screwdriver.  Sounds pretty slick to me!  My torque was checked by the guy too.  He said it seemed fine.  He cleaned it out, but recommended a new one anytime you have an old tranny.  Not enough cash though, so I'm sticking with it.  Thanks for the help.
Scott

[fitz]

Just take your time to adjust to TV cable.
This forum has some great info on how to do it.

[Lt.Del]

$500 for a rebuild. Man, you can't beat that even if you didn't get a new converter with it, which means no warrantly usually. 

[Jim Rockford]

did he install it or did you?  make sure you seat the converter correctly and don't force the trans up to the engine with the bolts if the trans doesn't sit flush with out force, something is wrong.

[Layne]

Lol yea! When I put my 400 in the c-10, I had the trans in park, and she was just crooked a hair. Man did I feel stupid when my friend came over and we struggled all day and he pointed out that maybe we should put it in neutral.

[malibu795]

If you go with a 4L80E, you can get a manual shiftkit or manual valvebody(guy in Dallas working on one).  That way you have one of the toughest GM transmissions, still have overdrive, and won't need a ECM.  It may take some time to get used to shifting it, but if you're a "performance nut" you might like it.

PATC currently make the for ~200.00 and you can run a switch for TCC control as well..
transgo and TCI make stand alone units for the 4L60e, 4L80E and 4L85E..