Planning overdrive trans swap

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Dutch Rutter

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Do I just give it 12v and plug it into the trans? And what do you mean about killing it?

He probably means killing the 700r4. They aren't known for being super resilient. Even though the one in my k20 DD has not given me any trouble.
If you do go with the 700r4 at least you will want to add a secondary trans cooler, shift kit, and replace the pan gasket and filter while you have it uninstalled.

But then again the 4l80e is from what I've heard an upgraded 700r4 with all newer guts. The common thought is the 4l80e will live longer then the 700r4.
 

Dutch Rutter

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I've also heard about gearvendor overdrive kits. Have not looked into them too much but would be able to add overdrive to your current TH350
 

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Do I just give it 12v and plug it into the trans? And what do you mean about killing it?

killing it like you would kill a 700r4, the 4l80 is much stronger stock and when upgraded. You adapter a tps to work with the carb and feed the controller that information, the controller then shifts the transmission as necessary. If you can find a controller and harness from a diesel truck with the tranny could save you time and money.
 

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He probably means killing the 700r4. They aren't known for being super resilient. Even though the one in my k20 DD has not given me any trouble.
If you do go with the 700r4 at least you will want to add a secondary trans cooler, shift kit, and replace the pan gasket and filter while you have it uninstalled.

But then again the 4l80e is from what I've heard an upgraded 700r4 with all newer guts. The common thought is the 4l80e will live longer then the 700r4.


the 4l60E is the upgraded 700r4, the 4l80e is built like a th400 with an added overdrive.
 

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If you go with anything that has an E at the end you will need a computer to control them. Im sure someone will correct me if i'm wrong but the first year for 4L60E was 1993 so look for something older if you dont want to get into the electronics. Although if you can source something like 4WDKC mentioned that would be optimal.

The flexplate will be fine as is.
 

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While it will still bolt up, the v6 transmissions dont have the same clutches a v8 tranny does causing you to burn them up alot quicker.

Good advice thanks, can you go a little more indepth about the "tps" off a diesel. Sorry lol im new at the 4l80s and what not, i hardly understand my th350 lol
 

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Good advice thanks, can you go a little more indepth about the "tps" off a diesel. Sorry lol im new at the 4l80s and what not, i hardly understand my th350 lol

TPS (Throttle position sensor)- tells the ecm/controller how much gas you are giving the engine so it can match the transmission shifts, line pressure, having these wrong will burn up the clutches in the transmissions. This is what the tv (throttle valve) cable on a 700r4 does and why so many people kill the 700 and bad mouth it.
 

Obwonkonobe

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TPS (Throttle position sensor)- tells the ecm/controller how much gas you are giving the engine so it can match the transmission shifts, line pressure, having these wrong will burn up the clutches in the transmissions. This is what the tv (throttle valve) cable on a 700r4 does and why so many people kill the 700 and bad mouth it.

OOH alright that makes alot of sence, what would a good year be to rob from, do I just rig it to the carb?
 

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If you're doing the swap to save money then the only thing I'd consider economical is a 700r4 swap, it requires the least extra parts and computer work to swap in. If you can get a low mileage one for a good price and get your tv cable adjusted correctly you'll be fine..otherwise I think your money is better spent buying a new truck with OD factory installed
 

bman1985

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Also I've read that the 2wd truck th350 with 9" tailshaft is only 1/8" shorter than a 700r4 so you don't need to mod your driveshaft. But don't quote me on that I haven't tried it. I realized it don't drive my truck enough to justify an Overdrive swap.
 

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