2001 Silverado 1500HD 4L80E transmission, feels like transbrake is on when in D even in manual 3,2,1

[Manny1500HD]

This a new issue from my last old thread when I had the transmission rebuilt and was having issues with no/ or low oil psi, and overheating. I put about almost 24k miles since. That is until recently I was hauling a Lincoln town car lowrider driving back home from Ontario, California.

I got off the freeway and started making my way towards the Cajon Pass in California and I could feel the transmission struggling on tow/haul mode looked at the temp and kept climbing usually it'll climb to near 225ish F and it'll cool back down by itself.

I kept going and sure enough I had to downshift to 3rd and it eventually started slowing down even more at 40mph. I pulled over and let it cool down, was back on the road all normal. I told myself this wasn't normal so.

I stopped using the truck and pulled the pan off, shift solenoid A the plastic housing had broken off. ended up removing the valve body because somebody overtorqued the screw that holds it in.

I brought a Transgo shift kit HD2 installed it, followed all instructions expect internal modifications. At first I had issues with no oil pressure, even though I checked it multiple times in park idling at full temp. did extensive testing of all new solenoids and all turned out to be working. Turns out after some research some were saying to check in neutral idling. I needed more oil.

I added more oil and now it was reading correct and had pressure in the transmission, I have Reverse and D gears but don't feel them engage at all but reverse does work real good has bout 200psi with no binding.

D and manual 1-3rd gears feel like transbrake is on but I don't have a transbrake. I jacked up rear diff and put jack stands and try again in D and 1st around 2500-3000rpm the rear wheels start to spin but the minute I let go of throttle it stops almost immediate.

I ended up calling Transgo the guy told me misplaced check balls or if the builder had did a dual feed clutch modification I would need to remove the plug in the case side near there center support bolt, so I pulled off the valve body again, I don't have a plug on the case side. kinda stumped at this point

I know TCC works? because I used my scanner and turned on the TCC through the scanner and tried to go foward and stalled the truck.

 

[Manny1500HD]

Here are some pictures of disassembly thru reassembly. also not the last picture shows that the rear center support bolt the 2 hole passages are not plugged up.

also where could I apply compressed air on the case side to see if 1-3rd gear clutches are engaging and disengaging? also I replaced 3rd and 4th accumulator pistons and the housing had some slight blemishes from the piston (cleaned up easily with scotch brite)

 

[WarWagon]

I could feel the transmission struggling on tow/haul mode looked at the temp and kept climbing usually it'll climb to near 225ish F and it'll cool back down by itself

The time it takes to overheat and warp clutch plates in a transmission when slipping is not long at all. It's just the clutch plates that quickly overheat at first not the entire transmission. Yes it will overheat if the slipping keeps up long enough. I have burnt the weak 3rd over-run clutches out by engine braking with the TCC forced on. Didn't even blip the temp gauge or make the oil smell bad. I put 50K on it after that before the TCC clutch started slipping.

The first picture bottom right, is that a bunch of burnt fluid or clutch material? Just a gasket?

I don't like to work on transmissions and find a good local shop. Because if you don't do it right the first time you get to do the entire damn thing over with new parts (clutches) because it slipped and burnt up.

Is a GM Reman available? I would core this mess out and go for a GM Reman as they have a warranty. (I have had luck with GM Remans in the past) Don't know what else is messed up or they missed to cause you this much trouble, again.

Otherwise I suspect you have burnt up some clutches in it.

 

[jrsavoie]

The time it takes to overheat and warp clutch plates in a transmission when slipping is not long at all. It's just the clutch plates that quickly overheat at first not the entire transmission. Yes it will overheat if the slipping keeps up long enough. I have burnt the weak 3rd over-run clutches out by engine braking with the TCC forced on. Didn't even blip the temp gauge or make the oil smell bad. I put 50K on it after that before the TCC clutch started slipping.

The first picture bottom right, is that a bunch of burnt fluid or clutch material? Just a gasket?

I don't like to work on transmissions and find a good local shop. Because if you don't do it right the first time you get to do the entire damn thing over with new parts (clutches) because it slipped and burnt up.

Is a GM Reman available? I would core this mess out and go for a GM Reman as they have a warranty. (I have had luck with GM Remans in the past) Don't know what else is messed up or they missed to cause you this much trouble, again.

Otherwise I suspect you have burnt up some clutches in it.

I've also had good luck with GM reman. It's what's in the 95 Tahoe that Nate has.

Later I found a good local rebuilder that offers the same warranty.

 

[Will L.]

yup. GM reman is best.
My diagnostics and rebuilding levels on trans is horrible. I avoid it like the plague, but commend you for giving it a go. I say inspect everything best you can and replace anything in doubt. When pros miss items and we try it once in a while- gotta expect realistic results. So be 100% as thorough as possible. This would include the manual to follow for rebuild- which is whats needed for your answers

Something @WarWagon added here long ago was the military manuals into our data base. Can you (since I am horrible at finding the stuff) post him the link to that manual? The hmmwv manual shows the full procedure iirc.
That will have in it how to test the clutches and probably a step or two that might have snuck by.

 

[Manny1500HD]

Sorry for late response, got caught up in work, by a gm reman do you guys mean a gm rebuilt transmission only or like at an auto parts store?
my advance auto parts store is selling a rebuilt 4l80e by a company called shift pro by ETE $2,359.99 plus a refundable core charge of $800 they also have a brand called Spartan?

I plan on keeping the core and just use it as an educational purpose in the future seeing as I have too much money invested in that transmission. but definitely plan on just buying a reman transmission of some sort.

 

[WarWagon]

do you guys mean a gm rebuilt transmission only

YES!!! Have you priced one from a GM Dealer?

You have any problems with a GM Goodwrench transmission you take it to a GM Dealer or any authorized service center.

The parts stores are in a race to the bottom with CHEAP CHEAP CHEAP patch it long enough to get to the next payday. With your "If it wasn't for Bad Luck You wouldn't have any luck at all." I would suggest GM only not risking the low bidder rebuilder to a parts store.

 

[SnowDrift]

Are you near central Ohio @Manny1500HD ?

 

[Twisted Steel Performance]

GEP does sell brand new 4L80e...

 

[Manny1500HD]

Are you near central Ohio @Manny1500HD ?

I am about 2,400 miles away from central Ohio

 

[Manny1500HD]

I got a quote from my local dealer. $5,191.91 with taxes & core charge which is $700
torque converter
3 year 100,000 miles warranty

 

[SnowDrift]

I am about 2,400 miles away from central Ohio

Probably too far to use my local guy, then?