I need a little help here. I have to pull the trans again to have it rebuilt AGAIN!! The original trans had about 110,000 miles on it. It started to free rev in 4th while at WOT. If I let off of the pedal and got back in to it, for a short while it was fine. Then it got to where it started doing it in 3rd as well. Then finally I lost 4th and had it rebuilt. When I had it rebuilt, I had the trans built up and installed a YANK 3200SS stall convertor and add 3.42 gears. Life was great for the summer (I do not baby my car) and then it started up again at the end of the season while at MIR. I still have 1st and 2nd, maybe 3rd. I was on the track in the second session and it started doing it again. It acts like it is free revving, the car will shake violently. I had enough trans left that I could get off the track and on my trailer. I was extremely thankful for that!

I have been told there is a tune in the car. I sent my file to a tuner, he read it, but has nothing to compare it to. Not sure how he knows there is a tune, but that is what he said. I have HPVI-2 that I can read from, but I am very new at reading and logging. My thought is that whoever tuned the car did not do it correctly. I try to keep an eye on my trans and oil temps as much as I can. I had a Hayden tube and fin cooler that I installed for the trans. I replaced it with a Derale 16 row stack plate cooler yesterday and it now has direct air flow whenever the car is moving and even more when at the track by removing the front plate cover. When at the track, I try to keep the temp no more than 225 when I can.

So, I have some questions;

1) why does this keep happening?

2) am I too high on the stall for daily and road course/track day events? (I try to hit the track at least 3 times a year. Work keeps me very busy, but when I on the track, I make it worth every second...)

3) could it just be not enough line pressure?

Mods please move if this is not the correct area, thanks.

 

I have to believe the tune is part, or most of it. What I'm going to say is an unusual situation, but here goes; I also have a 3,200 Yank. I've also been lucky,, because I have a totally stock internal 4L60E. I've never had the trans apart, save for the pan, to change fluid and filter at 100,000 miles. I've had 2 different, 600+ crank hp 427 engines yanking on it. I've never had any issues (saying this as often as I have is surely going to bite me in the ***, eventually!), and the trans is nearing 130,000 miles. I've made at least 40 dragstrip runs, and had several dyno tunes. I have to believe your tune is screwed up. BUT-Who "built" the trans? Who did the tune? Two important questions.....

 

You need to find a tuner that is very very experience with this trans. Its very tricky. If he has very minimum time tuning trans dont use him. I dont know why it started up considering u had 110k and this started happening. If u have a tuning software i would send a file to ecs or one of the bigger tuning shops and they can look it over.

 

I really think the time that was in the car when I bought it is at fault. I have the same issue as before I had the trans built and added the torque convertor at the same time. I know hardly anything about the tune. For now I am going with a place called Mail Order Tune, they are out of Texas. From what I am told, it's the same guy that uses Texas Speed. Anyone else heard of them?

 

Another place is, i don't remember full name but COW is in it he does 100s of mail tunes. Don't hurt to contact them

 

Stupid question. Did they flush the lines when they did the rebuild? If you have a partially clogged line then no amount of coolers will help. Just something to check. As others also said it could be low line pressure. If you have the HP Tuners just post a screen grab of the line pressures.

 

You could read the tune and post it here.

 

Good post. One other thing you may want to flush is the converter. It may have junk in it, too. OP-When it's slipping in 4th gear, do you know if the converter is in lock-up mode, or unlocked?

 

These things don’t lock at WOT.
Even if they did, and I know you can force them to, that requires a triple disc clutch in the converter. SS3200 doesn’t have that.
He said all gears basically failed…..

 

I did not say all gears failed. I know I lost O.D. and quite possibly 3rd as well. I was able to drive off of the track, through the paddock and up on to my trailer with out much issue.

I will look in to posting the file here. IIRC, HP combines both engine and trans for these cars.

 

Where are you located? I'm from the east side of the state in Oakland County originally, now I'm a half hour north of GR.

 

Did you put a line pressure gauge on the rebuild and check the line pressure? That's the only way to know the pressure is right. There is no pressure feedback to the PCM so it has no idea what the actual line pressure is.

Losing 4th but still having 3rd points to the 2-4 band. But, a common failure is the 3-4 clutch which causes both 3rd and 4th to be lost and you did post that 3rd isn't good so that points to the 3-4 clutch. It might kind of hold 3rd because that is direct drive instead of overdrive so it's not as much load on the clutch to move the car.

Did you change the transmission tuning when you added the converter? If not, that's surprising to me that it still drove OK and was shifting when it should especially at WOT without hitting the rev limiter.

Is your engine stock, or making more power?

The 4L60e transmission really isn't that hard to tune. It's not like a 6L80e or other higher # gears transmission where the controller has to time the apply and release of the clutches during a shift. About the only thing that would cause failures like you're having is someone screwing up the line pressure tables. Shifts are just a solenoid turning on or off, no PWM or timing. The PCM just applies or removes 12V to one of 2 solenoids and the shift happens. They just shift stupidly when you tune the shift tables wrong.

grinder11 - you're really lucky if you can keep any 4L60e alive and healthy behind 600hp.

 

This is the type of information and questions I like! I will reply with the limited detail that I can in a little while. I am currently working on my son's jeep, but I will get back to you. Thanks!

 

No, did not install gauge.

No tune.

At the time of both failures the engine was stock. It ran all summer just fine, went to a few track days during the summer, countless miles on the highway and city. We had nationals for our car club here, which is a three day event with a road course, drag and finally a autocross. I did not run in the last two events. A member from the east coast needed to use my shop to pull his motor and trans, so I spent two days in my shop working on his car. I have built a LS3 that I just finished building and it is waiting for new motor mounts to come in. Then I will install everything together when the trans is rebuilt and the Tc comes back. The body is in the air on my hoist, the rolling chassis in on the ground in pieces.

 

I searched and found a way to do it!!!

 

Does the car have the Autoblip installed? I had the exact same issue with Auto Blip and it scared the crap out of me in braking zones it would free Rev and accelerate.

 

Auto Blip is for manual cars...

 

Yes. I just realized your car is Auto. Read too quickly...

 

I can't help much, but maybe my experiences will give some insight.

My PCM was programmed by A&A Corvette in Oxnard CA when I changed from 3.15 rear drive to 3.73 to make sure shift points were correct and to forestall an unexpected downshift from 3rd to 1st at high throttle settings coming out of a turn. I ONLY use 2nd or 3rd on track but occasionally hit rev limit in 2nd because of a late manual upshift. When I am late, the engine shakes the car.

Before A&A reprogrammed the PCM, the engine would hit rev limit in 2nd and not upshift, shaking the car. Reprogramming the PCM stopped that.

No opinion on the converter, but my car has the stock converter and is fine on track. I have no use for a higher stall converter, which would make more heat to be dissipated. I like torque coming out of a turn.

For 12 years I have only used Red Line D-4 full synthetic ATF and change fluid and filter about every 7 track days. I occasionally have to come off track when trans temp hits 250.

My car has a DeWitts radiator with both engine and trans coolers, large auxiliary trans cooler in front of the condenser, B&M finned aluminum trans pan with two extra quarts capacity, Improved Racing engine oil thermostat.

23 track days, 6 at Buttonwillow Raceway, 13 at Laguna Seca, 4 at Arizona Motorsports Park. 117,000 miles on the car, Stock HP.

Still learning to drive at 77.

 

Just to piggyback on the suggestion to check the trans lines…. If you guys watch Cleetus McFarland YouTube channel, they lost something like two or three transmissions on one car until they decided to check if the trans fluid was actually circulating through the cooler. Guess what…it was clogged!

With all the stuff they break it’s really educational.