4L80E failure

No idea on the interchange- Should be a Chevy bolt pattern is a Chevy bolt pattern. Is the bellhousing a bolt on like maybe it could be used on the LS engines?

A rebuild is not that tough- get the ATSG book on that trans and go..All the electric stuff you should be able to test with a meter and a battery- that info will be in the ATSG book too.
 
Got an ATSG manual the other day detailing the rebuild procedure. I had a 96 3500HD junker lined up for $700 but this very good reference told me the 96 would not work due to a drilling that was eliminated in the 96 trans.

I've been studying but still feel a unprepared. That said,It seems the major assemblys come out in units and I expect my problem will be in the first unit to come out. I've already been warned that the OD clutch assembly requires special tools so if I reuse that I'm feeling somewhat confident to continue.

Summits has a TCI rebuild for 1500$ that may be a way forward as well.

Ironic that my first Auto rebuild will be one of the more complex:crutches:
 
I haven't been in a 4L80- but I suspect they (GM) didn't re-invent the wheel either. And not one of their transmissons takes a rocket scientist.

If you can scan and post the exploded parts pages, I'll be willing to bet figuring out how it all comes apart won't be a trick.

GM's 325-4L was the biggest PITA trans I ever saw- Caddy Seville FWD with a front to back engine. Even Allison transmissions are easier than that one.

Fuelie-- that tool says it's for a 4"T"80-- sidewinder. Does the "L" use the same one??
 
4L80 isn't to bad to rebuild and if you do your homework you can make most special tools to rebuild about any transmission.
 
Fuelie74 said:
4L80 isn't to bad to rebuild and if you do your homework you can make most special tools to rebuild about any transmission.
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In the back of the 700 case is that clutch piston forward/rev? anyway I made a tool for the spring pack from a 4" and a 7" steel bar and a 3/8 threaded rod about 8" long.....compress the spring set in the middle to get that snap ring in there.....that was the only really tricky part I know of in there, rest was fairly straightforward, but being as it was the first one for me, I was VERY paranoid, and have only done like 4 trannies, all since here in Florida.....

:bonkers::crutches:
 
Thanx guys, I appreciate all the information.

I was thinking I could compress a clutch pack using the mill table to secure some clamps. I've only seen the manual drawings so far but it looks doable. I'll check out the Ebay link.

Thanx
 
I've seen guys use the bottom half of a muffler clamp and threaded rod to compress the springs. It's 99% one of those "try it and see if it works" things. As long as you don't cut or roll any seals, get the faced clutch and steels in approximately the correct order, all the parts go back in the case and the lid fits, life is good.
 
Waiting at this moment for a tow truck to move the RV from the dirt to it's concrete parking pad so I can get it jacked up and on some stands. I keep circling and studying and keep telling myself I don't want to start this job on the dirt where it's presently parked.

Can't imagine why I didn't get the big Dollar tow truck to put it away except that I just wanted them done and gone, if ya know what I mean...:clobbered:
 
Handling an autobox on dirt is no fun. Been there, done that. Only "advantage" I know of is when it drips juice, the dirt soaks it up. But then the dirt becomes a gooey mess.

About the only thing you could do would be pull the driveline- it has to come out anyway,.
 
It's been a silly day here in the desert.

Started the morning with a bunch of electrical checks and one comes up suspicious so I elect to pull the pan for an inspection. But wait, the pan is full of oil, even a quart over now. Don't want to spill it all over my chest as I remove the pan do I? But wait, I have a pressure gauge hooked to the test port with three feet of rubber hose. Why not simply drop the hose into a gallon jug and let the engine pump it out?

Aren't I a clever boy!

The front of the RV is two feet in the air so it's a bit of a climb to reach the keys but I manage, engine starts on the button and all's good. First thing I notice is the puppy running so I look down and here's oil squirting. Damned hose fell out of the bottle! I jump down and try to secure the hose but I'd forgotten this pump is running 160 PSI! Hose is whipping like a fire hose and spraying everything in a fifteen foot radius. Including me! Puppy was clever enough to leave.

Jump back onto the iron step with my now oil soaked shoes and manage to get the engine shut off.

Oddly enough, Gage has retreated to the house and doesn't seem to want to help Daddy anymore...

And we're gonna trust this guy with tools???????? :rofl:

Anyway, all looks nice so far. No chunks in the pan, wiring is intact. Pan has sludge on the magnet and shiny micro bits in the oil. Brass color it seems. No steel bits at all.

I'm going to close it up again for now as the wind is whipping the dirt around. I'll have to rent a tranny jack next weekend.
 
Before you drop that heavy thing out of there, do a couple more checks. There are 2 solenoids that do the shifting, check them out with the pan off. I had one die in my pickup a year or so ago, $35 for a pair of new ones and I was on the road again.
 
GT6Steve said:
It's been a silly day here in the desert.

Started the morning with a bunch of electrical checks and one comes up suspicious so I elect to pull the pan for an inspection. But wait, the pan is full of oil, even a quart over now. Don't want to spill it all over my chest as I remove the pan do I? But wait, I have a pressure gauge hooked to the test port with three feet of rubber hose. Why not simply drop the hose into a gallon jug and let the engine pump it out?

Aren't I a clever boy!

The front of the RV is two feet in the air so it's a bit of a climb to reach the keys but I manage, engine starts on the button and all's good. First thing I notice is the puppy running so I look down and here's oil squirting. Damned hose fell out of the bottle! I jump down and try to secure the hose but I'd forgotten this pump is running 160 PSI! Hose is whipping like a fire hose and spraying everything in a fifteen foot radius. Including me! Puppy was clever enough to leave.

Jump back onto the iron step with my now oil soaked shoes and manage to get the engine shut off.

Oddly enough, Gage has retreated to the house and doesn't seem to want to help Daddy anymore...

And we're gonna trust this guy with tools???????? :rofl:

Anyway, all looks nice so far. No chunks in the pan, wiring is intact. Pan has sludge on the magnet and shiny micro bits in the oil. Brass color it seems. No steel bits at all.

I'm going to close it up again for now as the wind is whipping the dirt around. I'll have to rent a tranny jack next weekend.
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I"m sorry, but that's funny as shit right there......thanks for the laugh....

:friends::D:yahoo:
 
Thanx Gene, it is kinda funny now, wasn't in the first hour after....

Sixfooter, You touch on the anomaly I found. I have +12 volts to the solenoids but NO continuity between the hot pin and the two ground pins. I expect 20-40 Ohms each. I'll have to drop the pan back off for a detailed inspection (Which means pumping the oil out again:nuts: ) I looked at the harness casually when the pan was off before but Now I'll go back and pull each solenoid.

Trouble is the mode for both solenoids off is second gear and I have none at all...
 
Well, I shot my wad and am bitterly disappointed. Even though I was deeply suspicious of why two solenoids would fail together I hopefully installed new ones this AM. For nought.

Reverse is back solid but there's only frictional forward. Looked good with the driveshaft free though! All gears showed forward on the speedo but alas, nothing to the diff.

I'm fearing now the PCM is shot, still don't suspect the mechanical bits. Next test will be to ground the solenoids in sequence once I have the heart to jack it up again and start over.

At this point I'd call a tranny shop to tow it in and do it except for the confidence of the Prison Sex to follow. But in the end it seems I'll have to bend somewhere:sweat:
 
Nothing so far, reality has been rteally abusive. Last Saturday morning I had not one running vehicle out of six!!!! Bad luck abounds at the moment.

This weekend I'll be dedicated to the Vettes water pump and the Jags brakes.

This 50 mile a day highway high RPM work is beating up my cars that always did around town before:gurney:
 
GT6Steve said:
Nothing so far, reality has been rteally abusive. Last Saturday morning I had not one running vehicle out of six!!!! Bad luck abounds at the moment.

This weekend I'll be dedicated to the Vettes water pump and the Jags brakes.

This 50 mile a day highway high RPM work is beating up my cars that always did around town before:gurney:
Click to expand...

Overdrive?? 80 mph at ~2500 rpm....

;)
 
thought I'd give this an update as it's a bit of a poser.

Broke down six weeks ago and had the MH towed to a commercial yard that had a lift suitable for it's length. They tossed in a rebuilt trans for a great deal of money and pronounced it sound. It was for almost nine miles. After turning it off at a stop it restarted with first gear only. Drove the last seven miles in first gear and roughly 11,000 RPM. Or so it sounded at twenty five MPH's.:skeptic:

One of the guys came over with a TEK II scanner and determined the speed sensors weren't working. Came back today and believes it's the DRAC failed now.

I still believe we have a cheap electrical fault somewhere that WILL leave me stranded again until it's found.:fishing:
 
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