Trans “disengages” from engine on highway

I beat the hell out of mine in my 02 Camaro SS with the pressure cranked up, no other mods. But I never put a sticky tire on it so who knows. Im going garage built 4l80e on my 99 Camaro SS build just to be safe. Especially since it has 28" mickeys under the back of it. Lol.

 

Get a techstream on it and log the data when its happening.

 

Trade it in while high mileage Tacomas are still bringing good money.

 

They won't be interested in an out of warranty condition.

 

Ahh...must have missed that part.

 

I destroyed 1st,2nd,4th and reverse.
Burned all the clutch packs a few times.
Snapped the output shaft.

Mine was in a 2006 TBSS AWD. Loved that truck, hated the tranny.

 

I'm not surprised

Tbf, I didn't even know what maintenance was back then lol

 

Those transmissions kept my pockets lined from their debut in 1987 and continue to today .
Started out as the 700R4 with 1 lock up solenoid . With valve body upgrades it became the 4L60 .
Then with the introduction of pulse width modulation it became the 4L60E in 1993
The hydramatic division of GM is still making them in the 4L65E version . Thats good for me cha-ching !!!!!

 

Well now I feel lucky. Were the 1994 ones particuarly good?

 

I'm pretty rough on shit, but there's no way I'm 3 transmissions in a lifetime rough haha.

 

I went through 4 in 56k miles in my mazdaspeed protege. :X

 

1994 was fine but 1995 was a horrible year . 1995 was all by itself . in 1995 , The transmission casing at the reverse location use to crack . You would immediately lose reverse and all your transmission fluid .
You couldnt put in a 1994 or a 1996 as they wouldnt work lol

 

Making sure if you go WOT in D in a 4L60E is key to making it live longer. OD disengages the oil squirters on the drum and causes them to overheat. Still not at all optimal for a performance application but frequent fluid changes and racing in D does about all you can. Im surprised mine lived, we had the pressure turned way up and adaptive shift turned off.

 

Now I get why people have such a love hate for GM. Either their stuff runs for million miles, or its breaking in half. Top notch QC right there.

 

With few exceptions, thats really honesty the majority of mechanical items. Any boat guy will tell you Bayliners are and always have been cheap pieces of shit. I had a 91 Bayliner Capri that the new owner still enjoys the hell out of. It's never needed any major repairs and was never built to last this long. One of my coworkers has a 94 Bayliner that still runs like a top. Stuff gets a perception and it sticks no matter what the actual data shows to the contrary. With the exceptions of germans and italians, my family has owned just about every brand of car made and weve had bulletproof examples and absolute piles of crap. My dad and his neighbor bought almost identical 2002 Corvettes within days of each other. My dad's was solid at 42k miles when he traded it in for a convertible. His neighbors got bought back by GM through lemon law. (We suspect it had a slightly warped crank that was causing drivetrain issues).

 

Yeah thats a fair assessment I think. It would be fun to have access to actual stats on this stuff and see what the different in real numbers between Toyota and something like Dodge would be. They might be closer than we think.

 

As per my experience with Dodge, I doubt it. The really reliable Dodges tend to have been stuff with drivetrains from other companies. A ram with a pre-def cummins and an allison trans with dana axles is pretty much bulletproof. But none of that can be attributed to Dodge themselves. The SRT cars seem to be pretty solid but they get special attention paid to them. Id exclude any of the "halo" vehicles from reliability considerations.

 

very overfilled transmission can cause fluid to aerate when fluid gets into the spinning parts of the transmission. then sucked through pump and on to clutch pistons. cannot fully apply pistons= slip/neutral concern in gear. would take while to happen. IE extended drive on highway may do it.
also explains while it didn't start doing it till after they worked on it..

 

Quick Update:

The truck has been at the second dealership now for almost a month. They can't duplicate the issue after driving it a few times, so they ran some updates that were available and hoped that that would fix the issue. Needless to say, I had a guy pick it up for me last week, and it did the exact same thing to him on the way back. He was driving at the same speed I do on the interstate, but in a little more hilly country. He said there was a thud, almost like he hit something, check engine light came on, went into safety mode, and he coasted to a stop on the side of the road. The SW at the dealer said if it happened again, he or a tech would drive right out and hook up a scanner before we turned off the engine to pull the codes. Well... when he called the SW, he declined to come out and just left him hanging. He turned it off, back on, and finished the trip.

It's obviously time to move this issue up the chain. Truck has been at dealership almost 10 weeks now, and zero advancement in diagnosis. The common sense problem to me, is narrowed down to transmission. It seems that the issue occurs once the fluid is up to temp or potentially above (SW noted that when he drove it, trans fluid temp would increase slightly above normal on inclines) and there is a slight incline in the road causing a downshift. Maybe stuck piston or valve? Maybe valve body issue? Potentially a sensor or module issue? They did drain, refill, check and recheck fluid level. Transmission has never been apart up to this point.

I'll be getting in touch with Toyota regional to see what the next step needs to be. As a former tech, I'm struggling with the "no codes, no fix" mentality, as opposed to the common sense diagnostic approach. Maybe its just my lack of common sense assuming the dealer could fix their own product?

Any other constructive thoughts or input would be appreciated.

 

What's crazy to me is that Toyota allegedly has a thousand data points they can retrieve when you get into an accident. I can't understand how something so potentially catastrophic could be this puzzling with a system that is constantly reading data.

Hope it gets figured out soon!