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Another sick 4L80E

matuva

matuva

Tropical 6.5er
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Location
New Caledonia. An island in south west pacific, cl
A guy just phone me to describe a problem he is having on his K1500:

That started with the tranny being "rough" when shifting.

The guy was a bit discourages and parked the truck for 8 months.

He wants now to use the truck again, and had the bad surprise to see the tranny is slippering a lot.

Wether you're in R or D or 3-2, he says he has to rev the engine to move, and the truck moves slowly.
It is like the TCC doesn't lock or slips a lot.

I will try to read codes ASAP.

Any idea?
 
TC drained oil out. May take several hours to fill the trans to the proper level with the TC taking the oil up.
 
Check the fluid level first. It shouldn't take more than 30-45 seconds for the converter to fill back up if that is what happened. But in any case it sounds like it's low on fluid or the pressure regulator is stuck open.
 
Started by changing the filter on a trans that was sitting 6 months. Wondered why we got so much oil out of the pan. TC had drained back to the pan possibly because cooler lines were disconnected.

Fill Trans up, drive around block, loose forward gears. Fill transmission up, wait 10 min running, check and verify full level, drive around block loose forward gears, fill transmission up, check several times, drive around block... Took me several hours to get it filled up and also fighting foam from running the oil low. 2nd day after sitting overnight finally got the level full without overfilling.
 
Went to see the truck today.

Hooked AutoEnginuity scanner on it, and found no codes, except a misfire in cyl #4

No codes at all aout the tranny. Oil on the tranny was changed several days ago. Oil level is OK

Started the engine, and put on D, doesn't move till you rev the engine, and moves slowly.

It does the same in D, 3, 2 or position

Put in on R, rev the engine, and the trucks goes forward :skep: no rear....

Put on P and rev the engine, can hear the trans whinning :???:

solenoids?
 
Drop the pan and check the seal for the filter first thing. Sounds like he messed up the seal for the filter in it when he changed the trans fluid. The origanal 4L80E filter seal is a red silicone style seal that can be damaged fairly easily. The replacement seal will be a black rubber one inside of a metal sleeve and is reuseable many times. That is where I would start as it sounds like it is sucking air. if you have a pressur guage to hook up to it, that will take all the guesswork out of it.
 
Will do. Thanks for the advice.

Forgot to mention, the owner explains that the trans was having hiccup, then very quickly, stop working.

He drain oil a 1st time, cleaned the filter and put it back, no change. The oil that came out was black and stinky, he says smell like burn rubber,
and he found a kind of "mud" in the bottom of the pan.

He drained the oila 2nd time some days and a very few kilometers after, still very black...
 
Lack of maintence, or running it hot will fry a converter. Running it hard with the converter unlocked will cook one in a hurry too.
 
^^Front. Torque converter 'hub' drives it at engine RPM.

Obsevations: K1500 4L80E? Maybe 4L60E?

The 'whine' you hear is the pump singing it's death song. Which usually results in, low pressure = weak apply of clutches = smoked clutches..

Once the fluid goes black, not much can be saved.
 
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