hawkls7

I HAVE CONVERTED MY 4L60E GTO TO THE GM 4L80E TRANS . WE INSTALLED THE TRANSGO HD2 SHIFT KIT , WHICH HOLDS 1,2, AND THIRD GEARS UNTIL YOU SHIFT MANUALLY. THE PROBLEM I HAVE IS ONLY IN MANUAL FIRST AS YOU INCREASE THE RPM SAY FROM 3000, AND UP , THE TRANS FEELS LIKE IT LOCKS UP SO I THEN QUICKLY UPSHIFT TO SECOND GEAR. IN D FOR DRIVE THE TRANS SHIFTS EVERY GEAR WITH NO FAULTS.SECOND GEAR MANUAL NO FAULTS. I HAVE CHECKED AND CHECKED AND OVER CHECKED THE VALVE BODY MANY TIMES SPOKE TO TRANSGO , EVERY BODY I ASK TELL ME THEY NEVER HEARD OFF THIS PROBLEM BEFORE CAN ANY BODY HELP . WE ARE GOING TO TUNE ON FRIDAY HOPE TO SEE 1000 REAR HP.

TTS

Have you replaced the shift solenoids? Shift solenoid B could be partially clogged, as AFL oil increases it may not be able to vent forcing the 3rd clutch on = tie-up.

B's the driver's side solenoid, I'd replace both.

I haven't seen this problem either.

hawkls7

All Solenoids Are New Force Motor New . I Had This Problem When I First Put The 4l80e In My Gto. I Even Tried With A Standard Valve Body But Trans Still Locked Up In Full Manual First .as The Revs Increase , I Think The Trans Builds Up Fluid Pressure Or Something And Tries To Engage Another Gear Or A Band Its Shitting Me Any Other Experts Out There

FLT

iTrader: (1)

Take a look at the manifold switch data. This will tell you if your theory is correct about it binding with another gear being commanded with pressure. Sounds like you have a clutch pack that is welded or a sprag that is in the wrong direction.

hawkls7

Thanks For Response Vince . What Makes It Confusing Is If I Put The Trans In D For Drive The Car Will Shift 1-2-3-4 No Problem If I Put Trans In Third Gear It Shifts 1-2-3 , If I Put Trans In 2nd Gear It Will Hold Until Upshifted . But If I Put Trans In 1st Gear It Feels Like Trans Is Binding Up Or Locking Up As The Rpm Increases Could This Be A Transmission Fault Or A Tuner Fault Any Tuners Out There ,

TTS

The difference is, in low range the low brake is applied. The direct drum can try to apply at the top of first gear, when it does it is in fact a transbrake. Most hp transmissions have heavy return springs or a bleed hole drilled in the drum to prevent this from happening.

You won't notice so much in drive range, because there is no tie up. It's still happening, but you drive through the clutches.

I don't know if it's your problem, but it's a real possibility. You may or may not see this on the ps manifold, it's usually caused by centrifugal force, but could be a cross leak as well.

hawkls7

What Do You Mean About Manifold Switch Data. Also About Direct Drum Vent Hole , Do You Mean Behind The Piston . Originally We Used The Standard Drum With Holes Around The Direct Drum ,but I Still Had This Problem. I Have Upgraded The Direct Drum To 36 Element Sprag From Ck Performance. I Have Replaced All Solenoids Manifold .

TTS

The Pressure switch manifold is just that, they are pressure switches built in to the transmission. If you check the data on them during this tie up, you may see what circuit is being filled inadvertently.

Yes, I meant behind the piston. If you had the problem with the drilled drum it's not the problem.

chargedvx6

This may not be relevant but I had a similar issue. Apparently with the Transgo HD-2 kit (4L60E) when it is in limp home or a shift solenoid is failing it can engage 1st and 3rd simultaneously giving you bind. I had both 2 &3 shift solenoids go out and cause this.

FLT

iTrader: (1)

That is because of the gear command feature with the transgo kit. If you put the trans in manual low and it is in limp mode this happens. Two clutches circuits that are not designed to be on at the same time. I have to do one in an 80 in the next couple of weeks I will try it to see if it does the same as in the 60.

hawkls7

THANKS FOR YOUR POST VINCE HOPE YOU CAN SOLVE MY ISSUE

hawkls7

Hi vince have you had any luck with solving my problem , hope to hear , thanks

FLT

iTrader: (1)

No sorry. I did test quite a few 80's on our dyno since and have not been able to duplicate what is going on with yours. My suggestion is to remove the valve body and shift kit and start with a fresh kit from transgo with a completely different valve body. I'm not sure if the problem is with the gear command on yours or what. Honestly I do not like the gear command on the 80 and in the earlier kits I would leave that part of the kit out. The latest kit comes with a new separator plate that has three plates held together. Most of the tests I preformed have been with this kit. So that maybe might be the difference with the tests I preformed.

Couple questions for you I know that this thread was started in 4/08. Was this unit built for you or did you build it? If the unit was built is it possible that a seal for one of the accumulators was cut or was undersized? I have seen where oil can leak past an accumulator seal and get into a clutch circuit causing a wrong gear apply or even a skipped gear. I guess a bind is possible with the trans being in manual low because of the band being held on the planet. The seals should have resistance on the bores. Years ago I got some kits that the seals for the 2-3 and 3-4 accumulator were wrong. When I installed the pistons into the housing they just did not feel right to me. I never ran them like that and got different seals so I could not tell you what would have happened. Has this unit been back apart to see if any of the clutches have been damaged? Was this a "good used" unit to start with and was never rebuilt? There are many things that when I build a unit I address so without actually building the unit and not knowing the history, it is had to give advise.

What did you do as far as a computer to control this trans? Does it have a file for the 4l80e? If the car was equipped with a 60 did you change some of the wiring? Vince

MRZ28

iTrader: (15)

I am having this same EXACT problem with my 80E.... Hawk Does your first gear hold under WOT? Thats about the only time I can manually hold onto first gear.

hawkls7

Mrz28 i have not tried holding 1 under wot because i dont feel sure about it, it could be very damaging! Vince about my trans i have stripped and cleaned and inspected parts about 4 times and every thing looks sweet i havent cut short on the build i have spent money on all parts that are available to date. Before i converted my 4l60e to the larger 4l80e i called you and you gave me the best advice and i felt that even though you were busy you still had the time to guide me in the right direction compared to many other tecs i spoke to. Being in australia we have to buy many parts from USA and sometimes you dont deal with the right people but if i had to buy 4l80e parts i would be right on the phone with vince. With your recomendations i will give it a try as soon as pos hope it resolves my issue thanks vince

MRZ28

iTrader: (15)

Any New info yet?

hawkls7

I have built another gto , this car has its own tcm . Therefore with its pcm you cannot load a 4l80e transmission file across. I have just conected the pcs controller and will be testing my low first gear fault , if all goes well then it was the program file but if the problem is still there then it is a problem with the trans , ill soon find out when we start tuning for 1000rwhp

hawkls7

Now i have installed the pcs trans controller and all systems are go , finally i now can hold 1 gear at wot . that tells me that it is difficult to controll the 4l80e with the transgo hd2 shift kit with the ls1 cpu if you want to hold 1 under wot

MRZ28

iTrader: (15)

Thanks for the update hawk... I guess im just stuck with this problem till i can get a better controller.

darkhorsebob

I've seen this problem before. Remove the valve body and check the instructions very carefully. Make sure you drilled the hole in the shift valve bore in the correct location.