4l60e Broken Forward Sprag Symptoms. Aug 20, 2003 · The differential letting go under power can damage
Aug 20, 2003 · The differential letting go under power can damage the Sprag, But it brings into question the quality of parts used in the rebuild OR whether the Sprag was replaced at all. This is mainly because GM blessed us with some design flaws. Jan 5, 2026 · Here are 3 symptoms of a failing 4L60E transmission and how to diagnose the problems: No Third Gear - You put the vehicle in drive, start off the transmission, and shift to second gear. Includes shop-tested advice and upgrade options from Monster Transmission. 19. 18. Jan 24, 2008 · troubleshooting a 4L60E As Crosley pointed out, since the overrun clutch is applied in manual low, manual 2nd and manual 3rd this would explain why the person at the shop you took it to, suggested a possible bad sprag. While inspecting a 4L60E, we found severely worn forward frictions — clear signs of a failing sprag clutch. Extremely harsh shifts from P or N, normal shifts at WOT: EPC (Electronic Pressure Control) solenoid failed. I'm sure many of you have experienced input sprag failure in a 4L60E. . The overrun clutchs would allow the vehicle to move in manual low, in the event of a problem with the sprag. 48 vs 3. No forward movement in OD or D, but L2, L1 and R work: Forward sprag is broken. Its clutches carry more surface, and the entire rotating mass is stronger by design. The input sprag is a one way clutch that is solely responsible for moving a vehicle from a standing start. The forward clutches hold Dec 4, 2011 · 17. It is possible to remedy a fluid FYI 4L60E common problems / failures - Chevrolet Message Forum - Restoration and Repair Help Feb 1, 2016 · Discover the power of Passbooks and application charts for diagnosing transmission issues and identifying electrical or mechanical causes. Most likely a cracked input housing, or cracked forward piston means forward clutches are fused together. Oct 7, 2012 · LAUNCHING A CAR WITH A 4L60E. May also have worn boost valve. Jan 6, 2026 · First gear is shorter (2. Mar 17, 2011 · Common failures on 4L60E, problems any possible repair Problem Symptoms Possible repair Slow, slipping or no reverse “lo-reverse” clutches are worn out, fluid leak in the reverse apply circuit, or broken sunshell. Easy fix in pan. During teardown, we uncover chewed teeth and plastic debris, pointing to serious Apr 14, 2014 · Most likely a cracked input housing, or cracked forward piston means forward clutches are fused together. Try not to run or drive the car or further damage could result. 06), so it hits softer off the line, reducing shell and sprag shock. Dec 21, 2014 · I am trying to troubleshoot my trans failure and the symptoms I find on the net seems to fit both a failed forward sprag or a failed Shift Solenoid B (or communication to it). Jan 14, 2026 · Lost reverse in your 4L60E? Learn what causes it, how to diagnose the issue, and proven solutions to fix it. R&R. Fix as soon as possible or hard parts will eventually break. Car can safely be driven gently in forward gears until the repair.