Problematic 4l80e!

Should I drive it off a cliff and jump out or not jump out??

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C.Berry

C.Berry

Bad News
Joined
Aug 10, 2008
Location
Blacksburg, Va
so I’ve researched end on end about this transmission since I bought my truck last year and feel like I know a whole lot of nothing... As my luck would have it after this fantastic last few months now my 4l80e in my 99 suburban 2500 with 5.7 is whining has terrible vib over 3k which I’ve noticed for the last few months but now it’s really bad after this snow and being out working the truck in the weather playing catch up must have wore it out almost as much as myself!

My question is, if the truck vibrates and whines all the time instead of just in gear wouldn’t that rule out internals and be indication of torque converter? Or if that answer is no, what all vehicles can I pull a 4l80e from that’s straight swap into my burb? Can’t dish out the cash for rebuild right now I’m gonna have to make it work myself either swap it or pray it’s comverter! Anyone got a good idea of what’s going on here? I swear I’ve never met a tranny I like.... <(me making light of a extremely shit timed situation) all responses are welcome even if it’s not helpful may help to get a laugh!
 
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I know this isn't helpful, but it's all I can add.
 
a_kelley said:
Front pump if the whine varies constant dependent on rpm. SayS depends on years involved.
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This ^ is what I was going to say, likely the front pump. But if the pump is going, you may want to swap converters too. Take a sample of the fluid from the pan if you can and see how much trash is in it...hopefully it doesn't look like tranny-flavored glitter paint.
 
I’m gonna drop pan this weekend the fluid at dipstick is pretty and non metallic but I know that don’t mean crap really! I hope it’s just converter I don’t have hard shifts it has shifted hard a few times but I’ve been i it and let off in middle of shift typically!
 
If the computer reads something wrong, the 80 will go into protect mode which causes the hard shifts intermittently, but the shifts will stay that way until you cut off the vehicle. Doesn't sound like that's what you have going on, so I'd say front pump and converter. You're going to be doing the converter either way.
 
So while picking some food this afternoon after a 3 hour drive, I put the burb in reverse and slowly hit the throttle and had semi hard jolt and truck dies... heart sank for real thought I had hit something looked behind me nothing there, put it in park started it back up and went into reverse and no issue!?? Is this my converter starting to fail on me or reverse servo or both? Truly don’t have the time or money to just get this rebuilt so I’m limited on options. I’m gonna be needing to fix this ASAP and hopefully it’s something I can fix relatively easy and cheap?? Any thoughts?
 
a_kelley said:
That's odd that when started back, that it was fine. The converter lock up is either going to fail or not in my experience. No codes present I guess?
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No codes came up at all and I drove it about 15 miles to the house afterwards! Even stopped and got case of water. Very odd to me I checked my 4wd shifter and it was in 2hi I thought it had got knocked out of gear! Possible I had it in between park and reverse and it kicked into park which killed the engine?? Can’t find any info on web on this issue with reverse still working afterwards tho.
 
Wasn’t sure I was barely moving like maybe 1-2mph if that, had backed up possibly 5’ when it happened!
 
AtAfirst I thought maybe you partially grabbed reverse and it slipped back into park, But that wouldn't stall the engine. The only thing that would stall the engine in a fluid driven system would be the TC lock-up coming on.

That or it could be a downstream problem, as in something in the rear axle was bound up that forced the stall.
 
shelby27604 said:
AtAfirst I thought maybe you partially grabbed reverse and it slipped back into park, But that wouldn't stall the engine. The only thing that would stall the engine in a fluid driven system would be the TC lock-up coming on.

That or it could be a downstream problem, as in something in the rear axle was bound up that forced the stall.
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Interesting the gov bomb in the 14sf has had a workout last few months, I didn’t consider that! I’m gonna try to drop pan this week to check fluid in pan and see if filters clogged causing my slight whine I’m assuming I’ll be replacing the trans tho. It’s at 197k miles now I’m sure it’s the original trans too, so I’m lucky it made it this long I reckon!
 
As I sit here and re-read this, I am re-thinking whether a bound up axle would stall the engine......technically the torque converter should soak up the rpm difference between input (engine) and output as long as the TC lock-up is off.

going back to your original post, you said you have a vibration at 3k RPM. Do you have that Vibration in park/neutral at 3k RPM (i.e. not moving). If you shift into neutral at speed, does the vibration go away?

If you are driving at a steady speed once you hit overdrive, pull it down to 3rd and see if the vibration comes/goes/adds noises to the situation.

A vibration could be the lock-up bumping off the clutch face of the TC, it could be an internal issue....or.....maybe you are lucky and you have lost most of the bolts that connect the flywheel and the TC. Before you drop the pan, double check through the access hole that you still have all your TC bolts. Your clunk and stall might have been a bolt working its way out, getting sheared off....and fixing itself in its absence.
 
shelby27604 said:
As I sit here and re-read this, I am re-thinking whether a bound up axle would stall the engine......technically the torque converter should soak up the rpm difference between input (engine) and output as long as the TC lock-up is off.

going back to your original post, you said you have a vibration at 3k RPM. Do you have that Vibration in park/neutral at 3k RPM (i.e. not moving). If you shift into neutral at speed, does the vibration go away?

If you are driving at a steady speed once you hit overdrive, pull it down to 3rd and see if the vibration comes/goes/adds noises to the situation.

A vibration could be the lock-up bumping off the clutch face of the TC, it could be an internal issue....or.....maybe you are lucky and you have lost most of the bolts that connect the flywheel and the TC. Before you drop the pan, double check through the access hole that you still have all your TC bolts. Your clunk and stall might have been a bolt working its way out, getting sheared off....and fixing itself in its absence.
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Ya know I was considering checking flexplate bolts before dropping pan also, the vib seems to be worse while accelerating uphill at the 3k rpm range then when it shifts to next gear it will dissipate and isn’t very noticeable. I have noticed slight vibration while in park and not moving but nowhere close to same vibration while driving. Also to note when I am on a slight incline from a stop I have a heavy shudder in 1st gear even at low rpm, that goes away until I’m back into 3k rpm to go into next gear! I truly need to educate myself on transmission repair it and electrical is my downfall on vehicles!
 
The 4l60e in my 94 burb had the flexplate bolts come loose and made a terrible vibration while in any gear, it also had 266k on it tho, and when it went out pan was dropped and needle bearings were inside of it so I’m hoping this trans is t working its way to that point... I love the 4l80e, it’s a beast of a transmission no doubt but I hate having the feeling of it possibly going out any time and not knowing why!!
 
I went and drove it earlier no issue went up my icy driveway in reverse and cycled all gears up to 60mph with no hard shifts or issues but the vibration at 3k still seems to be there obviously it’s not fixing itself so may try to get the boss to let me pull it in the shop after work one day this week to check it over! Anyone know what 4l80e’s I can use out of other trucks that’ll swap straight into mine? It’s a 5.7 vortec so wasn’t sure if it would have to be 99 and older? Been looking online but not very informative info on most sites since this trans in so popular it seems more people have it swapped with other engine combos besides factory setups. lol
 
Just a friendly reminder, if you do think the TC has gone bad and try to swap ina replacement, you really want to replace or at least flush your cooler. I would bypass the factory in radiator cooler for an external unit. Years ago I had one go bad, mixed ATF and coolant in trans and engine. It was a mess, everything looked like strawberry milkshake....it brought zero boys to the yard.
 
shelby27604 said:
Just a friendly reminder, if you do think the TC has gone bad and try to swap ina replacement, you really want to replace or at least flush your cooler. I would bypass the factory in radiator cooler for an external unit. Years ago I had one go bad, mixed ATF and coolant in trans and engine. It was a mess, everything looked like strawberry milkshake....it brought zero boys to the yard.
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Lmao that was funny!! I have a dodge 5.2 cooler I could use but I may clean out my sbc400 cooler and make it a external unit the radiator in this has been replaced before I purchased it from what I can tell so haven’t given that much thought but easy to do for sure, and would def not want strawberry shake mix in my rad or any boys to my yard... lol good laugh thanks
 
I think TCI makes cheap coolers also so may save the cleaning hassle of a 79 cooler and buy one from summit... lol would suck to think it’s nice and clean and then clog and overheat the trans!
 
In general the biggest concern with the cooler is any metal that might be stuck in there getting another run at the pump and trans. Internals before going through the filter.

Keep us posted
 
It's not the worry of overheating from it plugging up...it's more about not pushing and crap that's in it through the new converter and freshly built transmission.

I'm a fan of the heat exchangers though, but only when paired with a large external cooler. It helps warm the transmission up and the external cooler does the rest of the work.

Edit: He beat me to it!
 
Yeah I had considered dropping Pan replacing filter and flushing trans before adding new tc to it assuming that would eat any crap out but my fluid looks amazing in this trans still perfectly red no blackish color or metallic flakes so praying it’s just tc and or some loose bolts but hard to tell until I can get under there and give it a good look!
 
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