Re: correct transmission for 6.0
 

I have not gotten a new transmission yet and I have a line on a 94 4l80e. I am wondering if that is too old to make work correctly with my 02 PCM, harness etc? I know I will need to get the harness changed, but are there other differences because of its age that I should be aware of? Any suggestions or info would be great. Originally it was with a 5.7.

Thanks

Re: correct transmission for 6.0
 

The early cases are slightly different, mostly the coolant lines. In '99 or so the cases changed, probably due to the LSx engines and the cases changed. Usually the earlier cases are preferred since the coolant lines are easier to run.

As far as the electronics, all the same as far as plug and play.

I would definitely have the roller clutch swapped out for a 34 element spray and have a TransGo HD-2 shift kit installed prior to putting it in your ride. Well worth the long term benefits.

Re: correct transmission for 6.0
 

Thanks. That helps.

Re: correct transmission for 6.0
 

The shift kit isn't a bad idea, but setting it up with a 34 element sprag is like a 5-700 upgrade, and one that isn't hardly justified on a stock engine. He'll have as much into that one part as the rest of the trans. Its not a BAD part, but wholly unneeded for what he's doing. Plenty of folks go north of 600 on the regular drum/clutches/sprag. If he wants to hit this thing with a 200 shot or something then sure.

From my experience (and occasionally from my own laziness)....most people don't want to take apart a working tranny.

Re: correct transmission for 6.0
 

Maybe you guys have been talking to my son! He is convinced we need twin turbos and 700+ hp! Of course he is 14 and has only my money to spend.

My primary goal right now is to get it moving under its own power. If needed I will look at tranny ungrades in the future.

Re: correct transmission for 6.0
 

it's a sin to take apart a good working auto trans
11th one in fact but Moses (Ol' Moe' to us old timers) ran outta room.

Re: correct transmission for 6.0
 

Are you saying there are no differences between any year 4L80e's or are you saying there are no differences between the 60 and 80?

There are plenty of differences in the electrical between the 4L60e and 4L80e. I'd like to see a thread on this swap. That way I could be more familiar with the changes needed at the PCM.

Re: correct transmission for 6.0
 

The original statement wasn't right to start with, there are wiring differences in "early" and "late" 4l80e's. We had a thread on it I dug up.

http://67-72chevytrucks.com/vboard/s...d.php?t=403605

http://67-72chevytrucks.com/vboard/a...1&d=1275308123

In the case of the 94 the PO mentioned, then there wouldn't be a difference, aside from the bolthole not lining up.

Re: correct transmission for 6.0
 

You talking about a 36 element sprag & custom Direct drum, New GM Sprag style drum, 34 element Sprag, & Race can be had for < $250. If the Drum & Race are in good shape, The 34 element sprag is a direct replacement for the 16 element sprag.

A 16 element Sprag can handle more abuse than people admit, Still stronger than the 8 element Roller Clutch found in most TH400's.

A '94 4L80E will work fine....IF it's in good shape?

Well I will definitely be going to hell:devil:

The ONLY way to know the true shape of an auto transmission is to tear it down.

Re: correct transmission for 6.0
 

I have not seen the 4l80e yet, just pictures so far, so hopefully it is good shape. Any suggestions on determining its health? Besides the word of the owner?

I did find this thread on converting a 4l60e plug to work with a 4l80e.

http://www.performancetrucks.net/for...-413157/page2/

So believe I would need to do that, and add an additional VSS.

Are the connections for the neutral safety switch the same between a 4l60e and a 4l80e? Just trying to make sure I understand all that will (or won't) need to be changed.

Thanks again for all the help.

Re: correct transmission for 6.0
 

Even for the 34 sprag, I don't think you'd be out the door at a trans shop less than $500. I'm working on the (ass)umption that the PO isn't planning on tearing into trans internals and day soon.

That said, the 36 is a badass unit. My wallet doesn't want to talk about Aluminum drums and things of such nature....

And cline, its cheating since you actually know how to put a trans back together.

Re: correct transmission for 6.0
 

It's easy to get confused about the different style's of Intermediate Overrunning Clutches.

From '65 to the early '70's, TH400's used a Sprag style Direct Drum.
From the early '70's to the end of TH400 production...Used a Roller Clutch style Direct Drum.
Early production 4L80E's also used a Roller Clutch style Direct Drum, After that GM started using Sprag style Direct Drums.

If you have a Sprag style Drum....The 34 element sprag is a Drop-In replacement, It retails for about $80.

The Roller Clutch style drum is still the most common style of Used drums & a lot find their way into 4L80E's.

Re: correct transmission for 6.0
 

Do you know where the dividing point is? The '97 changeoever, or those early like 93ish units?

....and why did they go from Sprag to Direct and then change back again, strength issue?

Re: correct transmission for 6.0
 

I do not know exactly when, But around late '92- early '93, I think it was a "rolling change".....One plant has more old parts than another.

The change from a Sprag to Roller Clutch then back again...Is because of strength, Spreads the load onto the Race more evenly.

Re: correct transmission for 6.0
 

So I went ahead and got the 4l80e. So I now need to make sure I get the right flexplate. I got a stock torque converter with it that requires a 6 bolt flex plate. The one on my 02 lq4 is a 3 bolt. So it looks like I need a flexplate for a Turbo 400 or a 4l80e. Does that sound right? And if I do that do I need to be concerned with a spacer? I have read in some cases a spacer is or is not needed but not sure how that applies here.

Thanks

Re: correct transmission for 6.0
 

iirc
if you get the 4l80e flexplate, it comes with the spacer, but I might be wrong about that. If you were to pull one out of a junkyard, the spacer is usually stuck right on the back of it, unless it was a 1999.

Should look something like this (not my pic)
http://www.ls1truck.com/upload/files...latespacer.jpg