brand new built 4l60e slipping off the line???

[big72red]

I just installed a brand new 4l60e built by a company called Performabuilt into my 94 Z71. Actually, I've done it TWICE! After the first installation, the truck was sluggish off the line. Engine would rev to about 1500-1600 before the truck would begin to move. Seemed to shift fine otherwise. It acted like it had a high stall converter in it. I did some research only to discover the trans builder sent me wrong converter. They had sent a 2000 stall converter. After a couple of arguments over the phone, I ended up exchanging it for the 1600 stall I had ordered in the first place.

Finally got a chance to swap the converters last night. The truck is behaving EXACTLY the same as it did before with the slightly higher stall!!! Fluid level reads perfect, pump is circulating fluid, and seems to shift fine once in motion. It just does not want to get moving from a stop or very slow roll(below 10mph). If I ease into the throttle on flat ground it climbs to about 1500-1600rpm then it starts pulling. If I hit the throttle any quicker, it flares up to about 1800-2000rpm and hits fairly hard...like side stepping a clutch at 2000rpm.

I was told it would take approximately 12qts to fill the new trans. It's only holding about 8qts before the stick reads overfull??? I tried adding a couple extra quarts to no avail. You guys have been very helpful in the past, so I'd greatly appreciate your insight on this matter. I'm out $2500 for the trans, $250 for the second converter, and about $200 worth of Dexron VI fluid, and this thing is still sitting in the driveway! Thanks in advance for any light y'all may be able to shed on this issue.

[big72red]

If anyone knows how, I'd like this thread moved to the engine & drivetrain section. Please feel free to put it wherever it should be. I'd hate to have to retype the whole post again on my phone.

[clinebarger]

I'm curious if it is taking off in first gear?

Limp Mode will default to 3rd gear ONLY....No upshifts. You say it IS shifting? Codes will set.

A 1-2 Shift Solenoid that is mechanically stuck, Or the Control Circuit shorted to ground.....Will cause a 2nd gear start, Then will upshift to 3rd normally, No 4th gear shift.


A 2-3 Shift Solenoid that is Stuck Off, Or Control Circuit shorted to ground.....Will start in 3rd gear, Will upshift at normal 3-4 shift.

A Mechanically Stuck Shift Solenoid will not set codes.

Shorted Shift Solenoid Circuits "Should" set codes, OBD-1 PCM's seem to pick & choose what they set codes for.

[big72red]

It shifts through all gears. Torque converter locks in overdrive, as well. Although, it seems reluctant to do so...I have to slightly ease off the throttle once up to speed to get it to lockup. If I just maintain throttle once cruising speed is achieved, the converter remains unlocked.

Sure hope someone has some clue to help out. Appreciate the reply. Please keep them coming.

[speedygonzales]

My local AAMCO shop is top notch and very trustworthy. Ask your closest location in Louisville.

[clinebarger]

This started with the new Trans? What happened to the old Trans??

Does the truck roll freely in neutral?

Performabuilt is no help on this?

They most likely dynoed the trans, That would explain it only holding 8 quarts of fluid.

[big72red]

I have tried asking several local shops. Nobody has ever seen anything like it. I'm sure they'd be glad to tear into it...to the tune of about $1000. Performabuilt is willing to check it out. I was just hoping to avoid pulling it again and shipping it from southern IN to Pennsylvania for them to do so. They've never encountered these symptoms either.

Yes, it was dyno tested before it shipped. All the more reason for everyone to scratch their heads on this one. Oh well, thanks for the ideas guys.

[Drewkimble48]

I know nothing about transmission except for a few things, thought I get that out there first. when you installed the torque converter, did you put it all the way in? The torque converter goes through one set of splines and then another set. If you look into the torque converter you will see 2 notches cut out. those have to be aligned with the shaft on the transmission for it to be able to go in. Now you said you were only able to 8 qts into the transmission. Well, considering you had another converter sent to you, I kind of doubt that it was filled with tranny fluid before it was sent, it would have been considered a Hazmat (have all the hazardous materials stickers on it) if it had tranny fluid in it. Something sounds funny about the torque converter to me