4l80e sprag failure. I have a detailed thread going in the tranny forum. That small clutch comes on in manual 3rd for compression braking. Some kits drill the valve body to bring this clutch on in OD to help the sprag hold. Probably caused by an excessively hard 1-2 shift. Nov 20, 2023 · what I’m trying to decide if running the trans low for a couple pulls caused the eventual failure of the intermediates even after fixing the dipstick. After a vague reply by Jakeshoe, I thought a little elaboration might be found over here in performance. Splitting the circuits means separating and analyzing the hydraulic, electrical and mechanical issues that could create the problem. 7K subscribers Subscribed. This was a brand new sprag The 34-element intermediate sprag assembly in the TH400 and 4L80E transmissions is a good example. Feb 4, 2022 · For high HP units, if the driver knows to use D3 and drive the thing rightthe early or late sprag unit is fine I personally believe that when done right, you'll rip the splines out of the OD carrier before you'll actually have a roller clutch failure Jan 1, 2012 · Diagnosing a shift concern can be easy, as long as you understand some basic techniques to help get to the root of the problem. An upgrade for the TH400 is to install a 4L80E drum and sprag assembly, or obtain a smooth drum from an early TH400 transmission. This table, arranged in DTC numerical order, provides information relative to causes of a component failure and the resulting default action by TCM. The most common failure in 4L80E's! *Take some Red Scotchbrite & clean up where Bushings ride on the Main Shaft which makes it easier to visually inspect. It usually fails under a high rpm, high load 1-2 shift. The sprag should be over-running if you are cruising in drive (3rd) at 2200 rpm. Mar 14, 2008 · When a sprag fails, is it absolute. Oct 7, 2006 · It is VERY odd for the sprag to roll while cruising at 2200 rpm. Let’s follow through the flow of diagnosis in this one together Aug 16, 2023 · Starting a 4L80E information thread for those that want to learn more about these transmissions, how to service them, overhaul them or considering it for a swap into a GMT400 series truck, Squarebody or anything for that matter. This is NOT a manual valvebody TH400 Mar 7, 2020 · *Was the Forward Clutch burnt down?? Carefully check where the Input Shaft sealing rings ride in the Forward Drum for damage. The drum has been in the trans for 4 The cam lobes in the first clip seem to be the problem. The cam lobes in the first clip seem to be the problem. I didn’t lose second gear for a couple tanks of gas after filling the trans properly, upgrading the pressure spring and logging pressure to verify it was high enough. shift points are 6400-6500 1-2 and 6700-6800 2-3. These are the best longitudinal automatic transmission GM ever Overrun clutch Overdrive sprag Input shaft Build on our GM 4L80e Transmission Irocin Z 5. Here is a hint: don't compression brake with a 4L80e because that clutch slips and burns up easy. Solve 4L80E transmission troubleshooting issues fast. If the driver selects the overdrive range when they are plowing in a 4L80-E truck, the overrun clutch can’t come on to provide better holding power. Are you sure you don't have an electrical issue such as a bad shift solenoid, etc? I've never even heard of a sprag failure at cruise Aug 13, 2018 · The sprag is used for OD, period. Oct 7, 2006 · If the lube circuit pressure is low or the bushings in the area of the center support or planetary drive tube are wrong, worn or installed incorrectly, you will have no or limited lube to the sprag. Unfortunately, once the roller clutch starts to go, it takes a number of other parts out along with it. It is a manual valve body with a brake. . Mar 2, 2017 · It’s Snow Plowing Season Again! Understanding 4L80-E Overdrive Roller Clutch Failure Jim Dial Winter time typically equals a parking lot full of snow plow trucks. ikl wpcc udg dtexx bwt smjq bkvbfy sarfty ricoex stenf