Thread: 3 speed to 4 speed automatic transmission swap

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I have a 78' Chevy step-side that originally had a 3 speed in it. I would like to put a 4 speed automatic in it, the 4l60e or whatever it is. I am pretty sure that those are electronic shift though. Is there anything special I have to do to put one in my truck or can I just bolt it up and go? Does it need any kind of ecm or anything? If so, can I get one just strictly for the transmission and where? Also, since it was a 3 speed on the column, does the linkage hook up and work still without having to do anything or does it need different linkage or what? All help and tips is appreciated.

Best years for your swap are from a 1987-92 Chevy pickup 700R4, these had all the factory upgrades and are non-computer unlike the later 4L60,avoid the earlier years as they had a lot of bugs.Also it is critical to properly adjust the T.V. cable,improper adjustment can toast one in minutes,google"700R4 T.V.cable adjustment" for how to info.

Originally Posted by JeffB2

Also it is critical to properly adjust the T.V. cable,improper adjustment can toast one in minutes,google"700R4 T.V.cable adjustment" for how to info.

He is right about that. here check this sight out I think it will help you

www.bowtieoverdrives.com/index.shtml

TCI makes a constant pressure valve body that eliminates the need for the critical TV cable adjustment.The TV cable is used just as a kickdown cable only.


http://www.compperformancegroupstore...nstantPressure

While we are on this topic I recently picked up a 700R4/4L60e how does one tell the difference?

The easy way to identify the trans is to scope out the electrical connector

700R4 has a 4 pin square connector on the driver side
4L60 (non E) has a 5 pin connector
4L60E has a round connector with many pins

If it has a removeable bellhousing, it is a 4L60E

Note that not all models are the same...there are wimpy 700R4 models and there are wimpy 4L60E models. Also, a 4L60E intended for an LS motor has one bellhousing bolt hole missing (passenger top) because the LS motor has no place to drill and tap this hole.
4L65 trans are a higher rated (torque) model and look just like a 4L60 on the outside.

mike in tucson

TCI makes a programmer for the "E" trannies which is a box in the cab with you that you can select the shift points,how hard are the shifts,lock-up,and is a free standing system.It is very expensive through.Stay away from any tranny that was used behind the 4.3 engines.The clutches in the v8 versions are better.
A common update is Trans-Go shift kits,with a 005 boost valve and a vett servo on the 700r's.

So, as a hypothetical question..... (oh no run away!) What if one were building a drag car and happened to have a 4l60e laying around and wanted to use it with a shift kit and just a ratchet shifter and not hook up any electronics or the T.V. Cable. Would that work at all?

I bought a TCI SSF 700R4 with a High Stall TC, I believe it has lock-up abilities.
Put this into a '76 GMC 1/2 ton pick up 6200 lbs, it is mated to a ZZ4 350 supposedly 355 HP or 410 foot pounds of torque along with 4.10 rear.

Should I be able to stamp on the gas and the rear wheels should be smoking right?

What is going on with the TC, I have a brake light that keeps coming on and going off depending on how I press the brakes while I am driving, somehow I think the TC is connected to the Brake peddle, does that make sense?

The TV Cable is ment for Kick-Down only and not Shift Points, and yet when I push the gas down, the 4 Barrels are supposed to open right? The tranny should shift to 3rd the engine sputters slightly, and shudders, like the TC is Kicking in and out of Lock-Up, the Vacuum at idle is around 15-16. The brake booster has a vac hose connected to the Manifold as well.
The reason I mention the vacuum is that I am wondering what roll it is playing in all this.

Regardless, My Tranny leaked from day one, the shifts were hard, very hard, not just firm, but violent. Had tranny repaired after it failed after 2500 Miles, had it reinstalled, and still having issues, now leaking again, not even 1000 miles on it.

Brand new Engine Brand New Tranny Torque Converter and Rear.

Heck, you want easy and no electronics to worry about, trash can the slush-boxes and put in the 3rd pedal and a 5 speed!!!!!!!! Mike Forte can set you one up right now and have it shipped tomorrow!!!! Oh yeah, lifetime guarantee against the dreaded TVR cable or whatever the dang thing is called!!!!!

Don't be shiftless, just grab another gear and go!!!!!!