If anyone can solve my problem then you are the true god of the car world since I haven't had anybody give me any guesses what it could be... so I really dont know how to describe the symptoms perfectly but I'm going to try anyways.

First off I have a completely rebuilt 4l60e with good components, beast sun, z pack etc but I am running a stock converter. My old tranny refused to shift into third gear at wot, then my tranny would not accelerate anything more than being gentle on the throttle over 45mph. Well the banging into 3rd was clear to me that I needed new clutches so when the slipping happened, which was random, car never was pushed hard before that because I knew it was wearing it out. I was 50 miles away from home and i went to pass a car from 65 and my rpms pulled up to 3500 when i didnt give it enough gas to even cause a downshift. I thought/think its related to the 3-4 clutch pack. But wouldnt a slip climb up harder (like redline) and not accelerate. Kind of had me thinking it was a torque converter lock-up issue.

Anyways, got a new rebuilt tranny with all the goodies to cure that wot 3rd gear shift problem. I broke the transmission in nice for the first 500 miles until I tested it out. It did great burnouts, loved hitting third gear perfect without any hesistation. So I thought my problem was solved. Now I have 1200 miles on the tranny and its pulling that rpm climb on the highway with me again!!! Its right around torque converter lock up too. Is the computer telling the converter to unlock when i give it anything more than idle throttle position over 40mph? Has anyone had that problem? I just have bolt-ons... headers, TD's, CAI, LS6 intake, and a B&M trans cooler thats massive, and a stock replacement torque converter since I didnt want to risk running the old one.

I just think its too ironic my tranny is doing the same thing but shifting into 3rd at WOT fine. I even did a WOT pull into 4th just to make sure and it grabbed good too. Fluid is bright red, and doesnt smell burnt. I don't think the clutches are shot, I just think its something else. ANY help would be awesome before I kick my winshield in.

 

anyone think it could be the tps(throttle position sensor)? Don't people have problems with them? my throttle body is ported and polished and my car has 185,xxx miles. Any type of advice be nice

 

no check engine light?

 

nope, there hasnt been any codes. The trans in the pcm is set on stock settings, never been touched. just air/egr and fan temps is all that has been messed with

 

Well i changed the throttle position sensor today and it didnt do anything. While testing it I think the tranny got worse. 1-2 shift is tight and firm but 2-3 is really hesitant and cant handle a load at all when in gear. My trans builder came over and rode with me but thinks the input sprag in the 3-4 went out. He thinks it is just a faulty part since i got 1200 miles out of it before it just freakishly failed under no stress.

Does anyone know if this failure is common around 350rwhp? And are there any input sprags that are better than ac delco? I hear borg warner's are good

 

Theres no sprag for 3-4. Maybe he said forward sprag but that would be a problem in all gears. 1-2 shift would slip too.
Borg warner dual cage is a good forward sprag.
Sounds like a problem with the 3-4 clutch or something in the 3rd gear circuit.

 

How high do you rev the motor during a WOT 1-2 or 2-3 shift?

Also did your "Builder" put a boost valve and HD pump slide spring in the pump?

 

I felt like it was an electrical problem at first too, but now its just slipping like crazy in 3rd and its hard to get it fast enough to go into 4th. this tranny is completely new as in my old tranny is sitting on my garage floor. seems weird that this tranny is doing the exact same thing my old one did. thats why I think its something electrical

 

Well i took it to 4 today comfortably in my 1-2 shift. yesterday it handled 6k fine. yesterday the max for 2-3 felt like it had a load and only go to 5k then bog down, then shift. today the 2-3 shift was at no throttle at 2700max before it slip up to 4500 at below quarter throttle. I feel like ill blow something if i do any kind of wot past 2nd gear. I know the pump has a better spring in it but I thought that was needed if your going to take the engine over 6k. Is it bad its in theresince my redline is at 6k still?

 

I mean the 3rd fluid circuit.

 

Heres a list of all my parts he uses in his builds.

New Seals, Gaskets, Bushings & More
High Energy Blend Clutches Throughout (Except 3-4)
New Hardened Reverse Sungear Shell
New Shift Solenoids
New Lockup Solenoid
New Filter
Teflon Bushing In Front Pump & Ext. Housing
Eliminate the P1870 Code
New Aluminum Accumulator Pistons (1-2, 3-4, Forward)
New Heavy Duty 2-4 Servo Return Spring
New Accumulator Springs (1-2, 3-4)
Upgraded #553 Servo
Resurfaced Reverse Drum
.500 Boost Valve & New Pressure Regulator Spring
Hardened Iron Pump Rings
Torlon .250 Checkballs
"Beast" Reverse Sungear Shell
Raybestos "Zpack" 3-4 Clutch Pack
Corvette Servo
HD Carbon 2-4 Band
New Improved Shift Spacer Plate
Sonnax AFL Valve
Billet Pinless Accumulators (1-2, 3-4, Forward)
High Pressure Pump Slide & PR Spring
HD 29 Element Forward Sprag
HD Low Roller Clutch
Oil Slinger Rear Planet

Now on this list if there is a part that is better than the other, the better part is what went in. He has 2 lists, one a basic rebuild and the other with upgraded parts so I tried to delete the basic ones so if I missed one I'm sorry.

Let me know if anything is junk or cause my problem

 

Sorry that sounds foreign to me, is that in the pan or something the computer does to shift?

 

The parts look fine overall each builder has different ideas of what will work best but in fact its more about hydraulics than parts. WWhen the person above referes to 3rd circuit they mean hydraulic circuit, Likley a leak in it. However other thinsg can affect line presure such as TPS when you have allready changed and MAF sensor can also and lower line will indeed cause 3-4 clutch failure and the syptoms you describe so would have to be considered also/

 

I know I havent had the tranny out but the fluid is bright red, with no signs of metallic on the towell when I wipe the stick. So if bad line pressure is applied to my 3rd and 4th gears, would it create a slip and no acceleration would occur? It makes sense, kinda like a straw with a hole in it. Does the power from the engine need sufficient line pressure to keep the gear engaged?

Ive also noticed my oil pressure is higher, probably irrelevant but I thought id throw that out there. Plus my idle has been low, like 500rpm in gear at dead stop. If it is the maf causing that, would it be too late to just swap that or do you think the damage is already done to the tranny?

 

Well some damage is done if it slipped at all. How much is anyones guess. But its worth a try and obviously you would need to solve any electrical issue before going back into the trans.

 

Is there any way to test if the maf is bad if it is not throwing any codes? I clean it once a year with maf cleaner. Nothing looks broken on it.

 

Well my builder found out what the problem was. He said it was a defective afl valve? He said the sleeve was overbored and i was loosing line pressure that eventually burnt up the 3-4. Makes sense to me and hes rebuilding the whole unit again for me but before I put the new tranny in I was wondering if anyone knows of any transmission oil pressure gauges? I have only found a TCI and VDO gauge. Id prefer something else so if anybody has any experience with the gauges let me know what works well and accurate.