Found the listed in the boneyard and I am looking for a slightly used transmission. What was stock behind the V6? 4L60E or 700R4? From what I could tell, it seemed to be a 700R4, but the trans mount was a little more solid than the 1986 T/A that I want to put it in. Also the pan seemed to be the same as a 700R4 - square. What is the main difference in the two or at least a tell-tale quick view before pulling it out of the car?

TIA, Jim.

 

If its the stock 91 and auto then its a 700r4. The 4L60e is electronic and will have an electrical connector and harness leading to it. Not to be confused with the 3 wire(4 prong) electrical connector leading to the 700r4 for TCC lockup.

The 4L is an electronically controlled trans and you would need a control box to run it. The 700 is fluid/pressure controlled with a TV cable.

If you do get it make sure the TV cable geometry is correct and matches what you are pulling out. You can put the old TV cable side by side with the new one and make sure they are the same length.

Edit- I dont remember offhand what the year change was, but the 700r4 first changed to the 4L60, which for all purposes is exactly the same as the 700r4 and just a name change. The lack of the E at the end means it is not electronically controlled.

So the 91 could have either the 700r4 or 4L60, which are the same, just a name change. However if for whatever reason it is a 4L60E then you would need a control box for it to work properly.

 

If your TA has an 8 cylinder as I believe all did , and this is a 6 cylinder's transmission , it will NOT bolt up to your engine , even though both are 700R4 !

Before you buy it , do a quick search here , and you'll see that the bellhousing bolt pattern is different between the 6 and 8 cylinder engines

 

I knew I forgot something, lol. Just didn't know which motor he had.

 

4L60 = 700R4; just renamed somewhere around 1990, when GM "standardized their nomenclature. 4 = # of gears, L = longitudinal as opposed to T = transverse (FWD), 60 is some sort of torque rating although I don't know in what units.

4L60E is the electronically controlled version. Clutches, power flow, case, etc. are essentially the same as the non-E; but the controls are COMPLETELY different. Looks more or less the same from the outside except for the wiring harness in the one vs the TV cable in the other. Mounts are the same. You're probably looking at that crappy "hydraulic" (fluid-filled) mount they used in the 6-cyl cars to keep the vibration from being too obnoxious. Has nothing whatsoever to do with E or not.

The 4L60E was first used in these cars in 93 or 94. All prior ones from about 83 up had the 700R4 later renamed 4L60.

A 6-cyl trans won't fit a V8; not even just the LG4.

 

Thanks for the help. I do believe the housing was a little different on the back of the engine. I am rebuilding a 305 to put back in the '86 and I am almost done. I will take a few pics from the bottom of the car this Sunday or Monday, but I'm feeling that it isn't a direct swap as you guys have noted. I can do engines, but transmissions are a whole 'nother field for me.