4l80e of the Express Van Variety Questions

So I hate sleeping in a tent, I'm not that old I just never enjoy it. My wife loves it, and I've reached the point in my life where I have a few dollars I could spend to go to different Motorsports events as a participant or spectator. 
So the obvious answer is a cargo van converted to a camper. 
Today despite my best efforts not to I made a low ball offer on an 07 express 2500 with a 4.8 and a 4l80e that has what the seller describes as "a selective reverse gear" .  My dangerous low offer was countered with being another 200$ and it's yours. 
So now the questions, before I get to the fun stuff of camperizing this and adding a second row bench seat what do I need to know about the different flavours of 4l80e? 
I found one locally out of an 04 what should I check before pulling the trigger. 
 

Impart your knowledge on me of wise and powerful grm hive mind. 

Um... selective reverse gear.  Is that code for "reverse doesn't work?"

I've never heard that term.  A 4L80E is a 4L80E pretty much.  They were offered with subtle differences over the years, like a 3-gear planet or 5-gear IIRC, different input drum splines, or other small details, but they are functionally the same since the 90s.

A 4L80E is vaguely an evolution of the TH400 that they added an OD and made it electronically controlled.  Great transmissions.

In reply to Curtis73 (Forum Supporter) :

Is it just me or do the ratios for the 4L80 seem better for hot car duty than the 4L60's? 

Lot of added weight with the 4L80. 

I would assume an automatic trans that is described as "a selective reverse gear" by the seller is code for "you will want to rebuild the transmission before putting this vehicle up for normal use".

... or are you asking if the 04 trans will fit in the 07?

Some of the 04 vans had a 4L60E in the 2500 if it came with certain combinations of engine/rear ratio/or if it was cargo/passenger.  Just make sure the donor van has the 4L80E.  You can't assume it's the 80 without verifying.  RPO should be MT1

Otherwise, I think they should be a direct swap.

pres589 (djronnebaum) said:

In reply to Curtis73 (Forum Supporter) :

Is it just me or do the ratios for the 4L80 seem better for hot car duty than the 4L60's? 

Lot of added weight with the 4L80. 

I would assume an automatic trans that is described as "a selective reverse gear" by the seller is code for "you will want to rebuild the transmission before putting this vehicle up for normal use".

It's all in what you want.  The 700r4/4L60E has the largest 1-2 ratio spread of any automatic.  It works for heavy street cars and light towing nicely, especially when torque is low.  The Express I just sorta bought is the 1500 with a 5.3L and 4L60E.  It has 3.42 gears, so for my light towing the 4L60E will be nice for pulling boats, making the van have a bit more pep off the line, but if that van had 3.73s I would be aching for a 4L80E because I like overkill.

GM usually does a good job with stall speeds and ratio pairing these days.  For me, I would gladly take the closer ratio 4L80E.  More weight, yes, but it's a van, and 4L80Es are much more bulletproof.

In reply to pres589 (djronnebaum) :

The 4L80 ratios are much more hot car friendly, because when they bunged an overdrive onto the TH400, they figured anything they parked in front of it would have enough grunt to deal with a 2.45 first gear.

When they made the 700-R4 (which was renamed the 4L60, which became the 4L60E with electronic controls) they switched the ratios to have a really shallow 3.0-something first gear, because the trans was supposed to go behind wheezer 305s in Caprices and they wanted to allow them all the help they could get.

For some reason the 200-4R splits the difference.  Maybe they figured the lighter duty V6s would tolerate a steeper rear gear, while the Olds 307s and Caddy 4100s (*hwack spit*) and Buick turbos could make enough grunt?  Who knows?  (There were no BOP-pattern 700-R4s made, while most 200-4Rs are dual pattern)

4l60's are much much much better after the $900 sonnax planetaries are added....

Ranger50 said:

4l60's are much much much better after the $900 sonnax planetaries are added....

You have my attention.  Is this something that makes them able to handle more power, or something that just lets them live longer under stock power?  Or both?

In reply to eastsideTim :

Both. Drops the first gear spread from 3.06/1.84 to 2.68/1.43, iirc or similar. It doesn't load the planet as hard.

How many miles are on it?  As everyone has said, the 4L80E is stout and the 4.8 shouldn't stress it too hard. Maybe it only needs a minor repair of some sort? Does it go though the forward gears ok?

I seem to remember something about TH400's losing reverse and the repair wasn't too big of a deal.  NO idea if that applies to the 4L80E.

Did the 4.8s come with a 4L80.  I'm not an expert, but it's the first time I've heard of that combo.

dj06482 (Forum Supporter) said:

Did the 4.8s come with a 4L80.  I'm not an expert, but it's the first time I've heard of that combo.

Only in vans, never in trucks or SUVs. 

I believe anything that came behind an LS engine should be plug and play. If I remember right they changed the selector switch plug at some point, but you can swap your selector switch if the plug doesn't match. 

In reply to Gearheadotaku (Forum Supporter) :

160k miles on the trans.

Curtis , you are correct. Selective reverse is code for needs trans or trans work. 
 

I just want to be sure the 04 trans will bolt up and not throw codes. Will confirm that donor is a 4l80 the van purchased is indeed 4l80 confirmed with the vin.

 For the price of the van a rebuild is out of the question. Van will be used 50% of the time towing. 

So my thoughts are junk yard trans and torque converter systems flush and add a trans cooler.

In reply to 1SlowVW :

You're on the right track.  I would suggest thinking about springing for a reman TC while you're at it.  Don't go with some big name like TCI or B&M.  Just call up your local trans parts wholesale warehouse and get a good quality reman.  Back when I was in the trans rebuild business, some quality remanufactured names were Florida TC, and Dacco was always a solid choice.  Precision is another good name (now owned by Dacco I think)  Shouldn't be more than $150-200.

Truth is, it's kinda hard to mess up a TC rebuild.  Cut the case apart, replace the lockup clutches, re-weld, balance, test, done. 

Not replacing it is fine, but the TC that is on the van now likely has friction material and possibly chunks of metal laying in the bottom.  If it lost reverse but has all forward gears just fine, you likely have metal swimming around.  If it's missing reverse, and forward gears are not right, you may have clutch and band debris which is less scary in terms of what is swimming in the fluid.

I personally wasn't in the rebuilding.  I did the managing, and that was 15 years ago, caveat emptor.  Just brain-vomiting what I remember.

I wish I could remember the exact years, but I'm 84.2% sure that 04 and 07 are identical.  I don't think there were differences in connectors or solenoids or wiring or shift linkage.  You also shouldn't need to stick with the trans from a van... silverado/sierra/etc should be the same.  .... at least in the 2wd flavor, that is.

Ranger50 said:

In reply to eastsideTim :

Both. Drops the first gear spread from 3.06/1.84 to 2.68/1.43, iirc or similar. It doesn't load the planet as hard.

Sounds like it might be cheaper to run a built 200-4R depending on goals and if non-electronic is acceptable, since it already has those ratios.  The BGN unit can handle lots of power.

Gearheadotaku (Forum Supporter) said:

How many miles are on it?  As everyone has said, the 4L80E is stout and the 4.8 shouldn't stress it too hard.

 

The 4L80E was installed from the factory behind a Duramax.  4.8L is like a cotton ball in front of that trans. 

In reply to Pete. (l33t FS) :

Unless you're going to tig all the stamped steel bullE36 M3 together, I wouldn't run one....

Curtis73 (Forum Supporter) said:

Gearheadotaku (Forum Supporter) said:

How many miles are on it?  As everyone has said, the 4L80E is stout and the 4.8 shouldn't stress it too hard.

 

The 4L80E was installed from the factory behind a Duramax.  4.8L is like a cotton ball in front of that trans. 

That's why it surprised me that it had failed . I didn't think the 4.8 would have enough steam to hurt the 4l80. 

1SlowVW said:

Curtis73 (Forum Supporter) said:

Gearheadotaku (Forum Supporter) said:

How many miles are on it?  As everyone has said, the 4L80E is stout and the 4.8 shouldn't stress it too hard.

 

The 4L80E was installed from the factory behind a Duramax.  4.8L is like a cotton ball in front of that trans. 

That's why it surprised me that it had failed . I didn't think the 4.8 would have enough steam to hurt the 4l80. 

Nothing lasts forever.  Could be that the friction material is spent, bad solenoid, sticking valve in the valve body or something else.

Transmissions are like brakes.  Even if they're overkill, you still have to replace pads, fluid, and hoses after a while.

Do you think it's worth it to flush the current trans? ATF is pretty cheap and the old atf was described by my friend at Batman levels of black. 

Doubtful it will help.  The black fluid is an indicator that something already went wrong.  [Ninja edit:]  If you brought a vehicle to my trans shop, typical diagnosis would be to drive it with live data, check fluid, pull the pan to look at what kind of debris is in it, check codes, etc.  If you brought in that van with black fluid and "selective reverse," I don't even need to drive it.  I would just quote a rebuild. [/ninja edit]

Transmissions can be frustrating.  You could try throwing a few parts at it.  Spending some time with live data might show some voodoo happening in there that points you toward an answer, but you'll just be throwing parts at it with a small chance of fixing it.

The fluid has specific grip/slip properties in the clutches, so either they didn't change the fluid enough which allowed the clutches to slip and fry, or something about the hydraulics failed at applying enough pressure and let the clutches fry, or it just wore out the friction material from normal use.

The real indicator is that it's missing reverse which (I think) is in the same circuit as 2nd.  So if forward gears operate normally, I think something about the hard parts of the reverse gear have failed.  If forward gears are also messed up, it could be clutches, hydraulic system, solenoids.... 

I think you're right... not worth guessing.  Just find a good JY unit and swap.  

How many miles on the current trans?

If you shop around, often times you can find a junkyard with a running example of what you need.  I did that when I needed a TH350.  Found a yard with an old Impala.  It had front end damage and one wheel pointed a bit sideways and no radiator, but I could run it on the 7 cylinders that worked for long enough to tell it shifted ok.

Curtis, 

Thanks for confirming what I was already leaning towards.

Have a junk yard nearby that has one from a 6l box van with a rusted out frame. Cab is already off so real easy to get that out. 
Going to head up with the flat deck next week maybe. I'll start driving it home and if it gives me trouble up on the trailer it will go. 

Sure thing.

I like to drain as much as I can from the JY trans first.  Pull the pan and filter, maybe stand it on the output shaft in a drain pan for a while, and pull the TC and slosh as much fluid out as you can.

New filter and pan gasket, pour a fresh quart in the TC, install everything, add 6 quarts to the pan, fire it up and add as necessary.  It doesn't need anything special.  Just Dex3/Merc.