When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hoping someone can help ID this. Any details appreciated. I bought the trans as a core basically. Had been gone through, but wasn't moving any fluid. Which lines up with the e clip being in the pan along with the boost valve assembly, and pressure regulator valve and spring hanging loose in the bore roughly... Along with very clean internals.
I believe I was told this was a Jake's D1 brake. It's definitely not a stock VB. Seals were left out of reverse servo/accumulator if that offers any additional clues. No markings I can see except for what's in the one picture, I don't think it's telling, but maybe for someone it is. Gasket may be a clue as I've heard some install metal to metal. I don't need a brake, and will likely sell or trade it, but wanna be able to accurately say what it is before I do. Thanks
Well you have a Factory/ Stock Casting, Pre-1997 Valve-Body.
Many of the Trans-Brakes are modified Stock Castings.
"Lester" and "8683479" are Original/ Stock Casting Identifications (Casting Place and Number).
Not really anything that identifies what you have as other than Stock.
The Third and Fourth Accumulator Housing has been removed and blocked-off (very commonly done)...
and the Separator-Plate and Gaskets are Aftermarket.
Thanks for taking time to reply. I didn't figure those markings meant anything and you confirmed that. When you say commonly done, do you mean in the context of trans brake valve bodies, or just generally?
Most of the Products offered for the 4L80E Valve-Body ("Shift-Kits", Shift Recalibrations, Trans-Brake Kits, Etc) come with a Block-Off Plate for the 3rd and 4th Accumulator Housing.
Thanks for the help. I don't need, or won't use a trans brake. Will it function normally, electronically controlled if I were to use it and just not engage the brake? Otherwise I'll sell or trade it for a stocker.
If you have the shifter in manual low, and the ECM attempts the factory programmed "safety shift"
it will lock the trans up
the safety shift is part of the factory tune that will shift 1-2 even if you are in D1
the idea is to keep you from over revving your pickup when towing
if that is tuned away, it should function prettymuch like normal for a 4l80e, you'll just have firmer shifts thanks to the blocked accumulators.
I'll be using an aftermarket controller (undecided on which one yet), I assume most of them can handle tuning out this safety feature? Thanks again for the helpful info. Sounds like I can finish the inspection, and plan on putting it back together, after determing what caused the e clip failure situation. I'd guess someone tried to do the job with something other than snap ring pliers as the clip looks deformed... My 65 Pontiac will then get OD, like I should have done long ago...
Yes most controllers do not perform the safety shift
FYI the 2-1 downshift with a computer is fine. Totally normal
A 2-1 downshift manually with the shifter can occasionally be a bit harsh. Often not too bad but some setups can bang a bit.
Thanks for the heads up on that. If I remember correctly, I was told by the previous owner that part of the D1 install was to install a Sonnax boost valve, perhaps the reason they were messing around with the assembly that lost the snap ring retainer. If I were to post a pic of this assembly, would you be able to tell if it's the Sonnax part? I'd like to know if the PR spring and the snap ring are all thats wrong in that little assembly.
I picked this up about a year and a half ago. Any chance it was correct at that time? Any chance of getting the written instruction material for this from you Jake? Perhaps with the purchase of whatever the newer correct parts are?
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.
7 Most Reliable High-Performance Engines GM Has Ever Built
Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.
4L80E Valve body ID 
