Nate2106

Alright guys this is my first post on here so be gentile. haha

I've got an 03' Hummer H2. 6.0L with a 4L65E behind it. Completely stock except for the 37" tires. In September I lost all gears besides first. First thing I did was replace my shift solenoids. Nothing!! Its at 175k so it was due for a fresh tranny, I decided to give the rebuild a try myself.

It was my first rebuild so I went with a complete rebuild kit from Monster Transmission. They also recommended a 1650 stall torque converter. (stock is 1300) The rebuild went great and everything went together smooth.

Clearly I didn't do something right. I had all gears except for 2nd. I could not get it shift out of first until I let off the gas. 3rd and 4th were completely normal. Manually shifting into 2nd did nothing and kept it in 1st. I checked my Servo 3 times, replaced the forward accumulator piston (the plastic one snapped) and the 1-2 accumulator piston to a metal one. Still nothing

No codes at all and the fluid looked good. (I know I shouldn't have) but I took it for a ride on the highway... blew the pump. Figured this was my chance to tear it down and take a look.

Finished the 2nd rebuild last week. Went through everything and checked to make sure everything was in order. Also bought a new pump. Everything looks fine on the inside. I went through the valve body throughly to make sure nothing was getting hung up, looked great. Reinstalled a stock torque converter with a 1300 stall speed.

On test drive, it drove the same as before. 1st was fine, Would only shift if i let off the gas, and would go right into 3rd, 4th seemed fine. I noticed that when I drive uphill from a dead stop it will shift into 2nd but it feels like its slipping, then pops right into 3rd. Only happens when going uphill. I can manually shift it into second but it yet again feels like its slipping. I checked the servo twice and it looks fine. During a test drive code P0757 popped up. "shift solenoid B stuck on" So I swapped it out and cleared the code. Still nothing.

So frustrated at this point, ready to throw it out and put a 5 speed haha. The other forums seem to either know nothing... or just tell me to give it to a pro and stick to carpentry. lol Any help in the right direction would be great. Thanks guys. Sorry its so long just want you guys to have the full story.

mrvedit

Welcome to ls1tech.com. Always good to have a new member that knows a snap ring plier from a crescent wrench.

And congrats on having the fortitude to rebuild a transmission; even if you had a few problems. We will try to help you figure this out.

Since the PCM completely controls the shifting, my first step would be to connect a scanner that shows the commanded gear to be sure the PCM is working correctly.
Next I would confirm that the servo end play is correct. With a ruler nearby press on the servo cover with a crowbar and estimate how far it moves in. The spec is .075 to .125 (about 1/16" to 1/8"). Around .185 you will start to slip in either 2nd or 4th.
Next, I would swap out the pressure manifold switch (on the VB) as this tell the PCM which position the shifter is in. Some of the weirdest shifting problem reported here were fixed by replacing it.

No, don't take it to a pro to fix it, but you might consider taking it to a locally owned trans shop if you don't have a scanner that car read and command gear positions.

Also measure and post your servo end play here and we'll go from there.

Nate2106

Thanks for the warm welcome

Got a chance to get it in the garage today. By the images attached you can see the cover sits 1/16 proud. When pushed in it sits 1/8 deep. By my advanced mathematical calculations, it has an overall end play of 3/16.

Is that enough to effect it?

Does a bad PMC throw a code? I've got to find a local guy to take it to test it.

mrvedit

I'm not exactly sure where the band starts to slip, but with your heavy vehicle I think you have reached it at the 3/16" end-play.

Here are some threads on lengthening the servo pin:
Lengthened Servo Pin:
https://ls1tech.com/forums/automatic...t-trouble.html
https://ls1tech.com/forums/automatic...-gear-all.html
https://ls1tech.com/forums/automatic...ckup-help.html
Worked:
https://ls1tech.com/forums/automatic...cond-only.html
https://ls1tech.com/forums/automatic...e-2-fixed.html
https://ls1tech.com/forums/automatic...-4th-gear.html

I don't understand why your servo has so much end play assuming you replace the band and haven't put many abusive miles on it.

Another idea would be to buy a Sonnax 2nd gear and 4th gear servo. The 2nd gear servo comes with a new/custom servo pin which you have to grind down for even the minimal 1/16" end play.

If you have the Transgo HD2 shift kit, it comes with big servo spacers which can also be used to tighten up the servo.

Profiter81

I hope this is a good place to post this being that it pertains to a 4L65E out of an '06 Cadillac Escalade ESV. This is my 4th rebuild, others were 4L60E that are still in operation. I have searched countless days and hours looking for information on the 4L65E, wiring schematics, code readers etc to troubleshoot this issue. Story begins back in March, when my father-in-law and I rebuilt this unit for a friend to try and save him some money. I should've left this one to the pro's because the 5 pinion sprag blew apart and the tranny was full of metal. Several part were replaced including the sun shell and the reverse input drum. I know I'm going to forget something so I fully expect questions to respond to before getting to the root cause. A complete disassembly of every component was done, including the pump, VB and of course all applicable components. We installed the tran-go shift kit which included drilling out the separator plate in several locations. We did not re-install the filters on the separator plate as it was told to us by a local shop, they're not needed if you keep your fluid clean and they do collapse causing pressure issues. So we haven't on any of the rebuilds so far. Removed all the plastic pistons and replaced w/ the upgraded aluminum, but did not go with the Corvette servo. Replaced several of the springs in the VB as indicated by the Transgo shift kit. I believe there were 4 springs and shim plate for the Servo mentioned above. Installed the Sonnax boost valve in the pump along w/ new vanes and cage (probably not the technical term). Replaced the pressure control solenoid on the VB as suggested by the Transtar sales guy, also where we purchased all of the parts. Replaced the torque convertor w/ a remanf stock unit. Reassembled with all new components, making sure to pre-lube all seals & O-rings. The 3-4 plate clearance was right at .060". Everything went back together and the tranny ran great for a week, including a trip down to Florida at which it decided to fail and not shift out of 1st. Since then, we've opened it back up, found 3-4 fibers toasted and a 4 tanged brass bushing that rides against the sun shell damaged. We found out later that there is an upgraded sun shell that uses a thrust bearing in place of this washer in which the 4 holes on the sun shell were removed. The ATSG manual mentioned nothing of this, I just happen to see it in a You Tube video. So we replaced the brass bushing with the bearing after complete disassembly, clean-up and inspection of all seals and O-rings. I failed to mention earlier that we air checked all the plate engagements with compressed air and they appeared to be cycling fine. We did find some spools in the VB hanging up a little so we fly lapped the ports until they moved freely, we're thinking this may have caused the failure during the Florida trip. Now after reassembly, we ran it on the lift and it shift in all the gears just fine. Took it down the road and it shifted in all the gears just fine for about 5-7 miles. After the 10th stop and go, the transmission decided not to shift into 2nd. We've had it out several times since and its shifted in to 2nd maybe twice but were up to 3,000 or 3500 rpms when it does. Unfortunately we don't have a Tech 2 or an expensive code reader to monitor the solenoids. We're not sure where to go from here other than take it to a local shop to have it hooked up to their scan tool. Any help is greatly appreciated as we've now had this thing for another month trying to diagnose it.
Thanks,
Matt

coryforsenate

iTrader: (1)

Hi Profiter81, welcome to the forum. You might get more responses if you create your own thread and separate your post into paragraphs for easier reading. And if I'm understanding correctly, you have all gears except 2nd?

Jays_SSZ28

iTrader: (2)

So I read through this again only to realize (AGAIN) that it was a three year old post. The guy hasn't even been here in three years. Drop the f bomb and god damn they're on it. Maybe the thread needs to be closed.