What I quoted above from Chris is what Gilbert (Ace Transmissions) had told me was the issue, he said he drilled a bigger feed hole or something to keep the pressure up... I don't know. I know in the 80e, the fluid circuit isn't even open for any kind of lockup apply until the transmission is in 2nd gear. Most of the answers I researched and was told was A: Pump B: Converter internal issue.

It was a 5 month ordeal and has a completely different unit then this one that had the issues... Haha, worst transmission builders I've ever dealt with I don't care how many people consider him a bad ***... He's not a vendor on here so I didn't even leave any feedback on my experience.

 

The 4L80E doesn't have fluid available to actuate the lockup valve in the pump until 2nd gear.
However,
oil that charges the converter (fills it so it can operate) is what actually applies or disengages the clutch.
The valve in the pump reverses the flow to lock the converter.
When it's in it's normal unlocked state the oil keeps the clutch pushed off.
If there isn't much flow, there isn't anything to keep the clutch pushed off.
Low idle rpm, restricted converter return from the converter being too far into the pump, and low flow are the causes. It's usually NOT a cross-leak in the pump, or a VB issue.
The flow is borderline on a stock 4L80E.
There are several things that can be done to fix/help the issue.

 

So Gilbert isn't worth dealing with?

 

First negative I have ever heard about Ace racing.

 

You can use him if you'd like, I didn't have the best experience. That's all I'll say!

Yea, that's why I used him. He came highly recommended on the interwebz, a little digging and talking to local people has proven otherwise. Oh well live and learn!!

 

after a host of other issues I finally get the transmission in. now my trans is doing the same thing. fml! so drill the pump? does anybody know exactly what needs to be done so I can tell my builder? From calling and a little research Ive been told 60 thousandths on the converter charge circuit and block the converter regulator. Does this sound right?

Found this on another sight credit to chris718

No secrets here. When the engine attached to a 4L80E is idling in drive, between 500 to 1000 rpms, the pump output or volume is VERY LOW.This is true even with a fixed line pressure system.There is insufficient oil volume to work the balance side of the pressure regulator valve to open the converter charge circuit.With fixed line the pressure may not reach the fixed value until sufficient pump speed has been maintaned.I tested this with a BRAND NEW GM PUMP,and BRAND NEW GM VALVE BODY .The little line to lube hole is enough to feed the CONVERTER REGULATOR VALVE to allow it to regulate BUT still does not have enough volum to keep the converter clutch off in some applications.It is therefore recommended to block the valve in the position it is in when the engine is not running so that there unrestricted ,unexausted flow of oil into the converter to hold the friction disc off of the converter cover.The nature of a pressure regulator valve would lead one to believe that the lack of oil at the CRVALVE would cause unrestricted flow into the converter ,but only if there is an oil volume available to flow thru an unrestricted path. There is a point reached where oil volume is enough to only partially act on the pressure regulator end face to introduce line to the converter in circuit,but not enough to hold the clutch off at the start of the CRVALVES beginning of regulation of oil.

 

my truck was doing the same thing, locking up in drive and reverse but only when cold. it would stall the motor and acted like a standard.
ended up being the pressure manifold bolts were a little loose. tightened them and its fine

 

cdub 81 do you think the restriction (dirt dobber) caused the clutches to drag? I saw it was overheating and dragging clutches. im guessing you had compound issues?

 

Oops, guess I missed this.

That was the original thought, the trans was taken back out and gone through again with a new cooler installed. All back together, same damn thing.

Gilbert built a complete diff unit and installed it, overheated again...

So after he had the truck 3 weeks, he ended up saying it had the older style mainshaft and that's why it was overheating... Weird, you'd think that would have been seen in a complete build. He put the "right" mainshaft in and now its been good as far as cooling.

On this second transmission if I let it idle for 5-10 minutes and then put it in gear the converter will drag (semi lockup) until I get the rpms up. I plan to pull it again and have that issue fixed by somebody else.

I will say Gilbert did make it right in the end as far as money and an apology.

 

I stumbled upon this thread a few weeks back. I have a 1968 Pontiac Firebird with a 496 stroker, 4L80E with Jakes Performance rebuild kit completed by a local builder, a manual harness from Jakes, a 3400 rpm stall converter from Circle D single disc, Long Tru-Cool Max transmission cooler P/N LPD47391. I had the following issues, my transmission was locking up in 1st and 2nd gear as well as runing 200 to 210 degrees with a smaller older cooler. I had to keep my foot on the gas at stop lights to preventing stalling and when backing up the car would buck much like a 4x4 turning tight corners. I called Circle D and explained my issue and this thread, the rep at Circle D recommended I try replacing the lube regulated pressure valve with part# 34200-14K ($58.77) . I picked that valve up yesterday from Summit Racing here in the Dallas area. I installed today in a little over an hour, as took my time, then added 6.5 quarts of dextron VI synthetic fluid and took it out for a test drive in 95 degree tempatures. All I can say wow, get you one of these valvs and the cooler listed above, these two items solved my lockup problem and my cooling issues. I drove my car like I stole it, the temp never got over 175 and as I down shifted pulling up to stop lights it idled just fine at 800 rpm. This video is helpful and awkward all at the same time ,