4L60e Transmission issues
 

I attempted my first 4L60e transmission rebuild, it had started slipping more and more and the fluid was burnt that is the reason for the rebuild, for my first try, it didn't go so well, I installed all the O-ring and seals, the worn bearings and all the clutches packs and plates and all solenoids after I though all was well I installed the transmission back into my truck (2006 Chevy Colorado 5cyl) and now all I have is low and reverse, when I shift to 2nd it feels like it engages but when I try to go it feels like something is holding the truck from moving, if anyone has any ideas on what I screwed up please let me know!!

ltomlinjr

The "something is holding" often indicates that the trans is trying to engage multiple gears at once.
Do you remember checking the clearance of the low/reverse clutch?
It sounds like it is not disengaging fully.

What book(s) did you follow for the rebuild?

4L60e Transmission issues
 

Hi mrvedit,

The manual I was using is a "GM Power train 4L60-E" that I got from a friend, and well now, I did not check the clearances so I am in the process of removing the trans and checking all the clearances, I see now that they mention the clearance checking in the manuals for a reason, well I will let you know how I progress, thank you for you response.

ltomlinjr

Good luck with the diagnosis.
Too bad your first rebuild had a problem, but I am confident you will figure it out and then be very proud of your accomplishment.

If you have a few days, this is an excellent 4L60E rebuild book with color pictures:
http://smile.amazon.com/Automatic-Ov...502/ref=sr_1_2
About $18 now. The ATSG 4l60E manual is also a good reference.

To check the low/reverse clearance, you apply air pressure to a hole in the middle very back of the case. You can then see the movement in a small slot nearby. I would suggest testing this before you disassemble the low/reverse clutch area. That should answer whether the problem is there or elsewhere.
The "How to" book says .010 to .035 is a good range. Different width "selective wave plates" are available, but generally the existing one should be fine.

Good luck!

Hi mrvedit, I pulled the trans and checked the clearances and they were good .022 to.027 but I did find a mistake I made, I installed the 4th apply piston backwards, I corrected that and now I get a reduced power error code P0601 and shuts off before I can check fluid level, could this be PCM problems??

I'm not familiar with P0601. Searching other forums it appears to be "Memory Checksum error" which would mean the PCM found an internal fault.
Disconnect the battery and make sure the TPS, MAF and other connectors are clean. Also check your ground connections to the engine and chassis. Reconnect the battery. If the code persists you might need a new PCM, but people on other sections of this forum might have better suggestions.

While you are in there you may want to check that the Forward Sprag is installed correctly. If the Forward Sprag is installed wrong the trans will bind-up when shifting into 2nd gear. It is very easy to install wrong if you are rushing through and only look at the diagram in the ATSG manual and don’t read the captions. Don’t ask me how I know. Some things we learn the hard way.

Good point.
There have been plenty of upside-down sprags reported (admitted to) here.

Well while going back through all of my tranny I did find the forward sprag backwards so I corrected that issue and I decided to completely go through the rest of the tranny to make sure that was the only blunder I made before I reassemble and install it back into my truck, I will keep you all informed on my progress!!

Thank you all sooo much

ltomlinjr

I’m glad you caught it. It is real easy to install backwards. I bet if they would admit it almost everyone has done this at lest once.

I got rained out today so I did not get to install my tranny yet but everything else look good, I will give it another once over in the garage and tomorrow if it is not raining I will install it and test it out, I will keep you posted on my progress!!

Fingers and toes crossed. Hopefully Murphy will stay way.

Hey Guys, that was it, I was the problem, the reversed sprag did it, I also had a bad PCM and after replacing it and relearning it has an error code P0315, I'm trying to figure out how to reset it for the state inspection, any ideas??

ltomlinjr

A PCM needs to "learn" the exact relationship between your engine's crank sensor and camshaft sensor.
You need a scanner that can set "learn" mode. The HP Tuner scanner has that ability, but I suspect many others do too. The dealer or a local shop might do this for a nominal fee.

And congrats on rebuilding the trans and figuring out that the sprag was reversed.