ToastedPirate

Im a mechanic, I am capable of rebuilding a transmission but havent done it in years. So i have some questions.

I have a 2004 4l80e I got for free with my engine, the transmission pan has no metal in it but it is inside the filter when i pulled it open.


If i was to rebuild this, I see many options. There's Rebuild kits but they don't include clutches or a converter. Im assuming with the metal, at this point I'm looking at a full rebuild of clutches, seals, bushings, bearings, torque converter.
Do you usually need a valve body? What else would be needed? Is this even worth doing? To send it to the transmission shop it would be about $2500 my shops cost to get it rebuild(swapped out, they have already built ones and take yours as a core)

Thoughts? any advice appreciated.

FranksCustomTrans

If you are unfamiliar with the unit the 2500 is actually a really good price to have a pro do it ,
But yes full kit including frictions, steels, bands, seals,bushings, likely pistons and very commonly the forward drum and direct drum need replacing and more common than not the pump also.
The valvebody will at the very least need the good cleaning AFL checked for wear and drop in TCC/PWM valve from sonnax.
Replace front sprag for sure if its the late style small roller type with GM only I HAVE HAD ISSUES with aftermarkets of these the BLUE SPRAG.

ToastedPirate

Its funny, you pull up rebuild kits and most don't include clutches or any of that. It's all just seals, bushing, bearings and gaskets.

I was thinking..... That seams wrong. The amount of metal I have something is shredding.
What, I'm not sure.
I may take it apart and look at it all. Funny thing is - it still drove. Not sure how well since it came out of a crashed van so I could go higher then 2nd gear before it felt like the van was gonna fall apart.

strutaeng

The complete overhaul kits I've bought before (all seals, gaskets, frictions, steels, filter and electronics, other misc. items like pump/rear bushings) has been on the $600-ish price range. You can probably piece them together and maybe get a better price? IDK. Plan on additional bushings being replaced and roller clutch/sprag. AFL valve, add that as well, and a few other valves that can be improved over factory ones like boost valve. That's gonna be close to $1,000 in parts alone. And we are talking a stock/stockish rebuild here.

Hopefully the forward drum isn't damaged from the common input shaft rubbing.

5.7stroker

iTrader: (36)

You are looking at around $1k in quality name brand parts for a full stock rebuild if you bought them yourself, not including hard parts like a VB, pump, forward drum or direct drum so it's a matter of deciding if the $1500 or so in labor is worth it or not.

If the shop has a transmission dyno and actually tests the transmission on it before selling it to you, there's some good piece of mind that comes with that.

By quality I mean parts like Durabond bushings, National Seal Pistons, Borg Warner High Energy frictions, non aftermarket sprags, bands and electronics. AcDelco electronics are the way to go, Rostra solenoids and internal harness are proven also.

You can convert the low roller clutch to the early style (which is a better design) but it requires changing out some parts from late model to early model.

If the shop has anything to do with lizards, monsters, or dogs that are mad..... run away fast.

FranksCustomTrans

Honestly with 300k I would plan on master rebuild kit, AFL VALVE (Probably easiest to get a reman VB from sonnax) all bushings, forward, direct drums, center support likely an more than likely a pump or at the very least new gears, New harness and solenoids. Int sprag unless new on drum you get I usually get it with the drum but BEWARE more than once I HAVE CAUGHT THEM INSTALLED BACKWARDS ON NEW DRUMS SO CHECK. new accumulator pistons.
As far as updates the earlier large roller input sprag is great but you must use as assembly with OD planet and shaft, Dual chamber the direct AKA dual feed though its not really dual feed just both chambers of the direct drum used for 3rd.

ToastedPirate

Here's a question to add options for me

I can get a 4x4 4l80e for $200 that I know was running and working. He crashed his truck.

Would it be worth buying that and throwing the innards into my housing?

The case and the output shaft I think are the differences no? Anything else? Run away?
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Or should I just find a 4l60e? I already built the cross member, and the donor van i got with all computers and harnesses was a 4l80e so I'd need to swap all that.

dw456post

Don't go to a 4L60 !!
If you get the 4x4 trans, use your tailshaft and housing.
Get a new internal wiring harness. You will need a new input shaft O ring also.
You will probably find a few more things needed.

ToastedPirate

So pull all the guts out of my mucked trans and slap all the internals from the 4x4 into it except for the output shaft. Would anything on my 2wd output shaft be damaged from all that metal? Lol.

If I do this I would order a bearing and seal kit to redo all that. Hmmm choices to make.
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dw456post

If the 4x4 trans is the same bellhousing as yours, and it was running, I would use the 4x4 trans, get a used tailshaft, remove the guts, slap in the 2wd tailshaft and other innards. FRANK--- isn't there a plug back there that needs a small hole for lubrication---or is that a 6L80?
Put on your tailshaft extension.

5.7stroker

iTrader: (36)

When converting a 4wd 4L80E to 2wd, you need:

2wd output shaft
2wd extension housing
Tone ring from a 2wd 4l80E for the rear VSS
The rear housing lube plug needs to have the hole in it for 2wd to lube the tail bushing, and that plug is included in the rebuild kit like a 34002EAF

Slapping a running and working 4wd into a vehicle that is 4wd and having to completely tare it down to the output shaft to put the compatible parts into a high mile 2wd 4L80E are 2 different beasts.
Most cores sell for $500 so $200 for that 4wd for a running unit is a steal, and if the hard parts are in better condition than your current 2wd, then that's a plus.
You could very well spend $200 and find out that the 4wd has a pump, VB, direct drum and forward drum that are worn enough that they need replaced, not to mention the rest of the parts that may be due for replacement. Or you could get lucky. How many miles are on the 4wd unit and what year is it?

In any case, I'd still replace all the frictions and steels, bushings, sprags, bands, and pistons if needed and get a 34002EAF to cover the rest of it since it has to be torn down. Address the AFL and TCC like Frank said if you aren't going to vac test the VB. Do the "dual feed" mod and rollerize the rear for cheap. The electronics can always be replaced later by dropping the pan if something goes bad, assuming that the ones in the 4wd are good. Make sure the rear servo pin travel is good.