Stage 3 4L60E lost reverse
The tranny is only a couple months old, and has no racing on it, and definately no nitrous because I never found it working right.
On the highway, around 70-80 it would constantly shift between 3rd and OD, pretty much as soon as it would switch to OD it would downshift back to 3rd, wait a while, shift to OD, and then immediately back to 3rd again. This would repeat indefinately.
I am using my stock torque converter, a 4L60E Stg 3 tranny build by a reputable shop out of San Antonio, and a properly sized transmission cooler to keep everything running cool.
Can anyone offer insight? The shop offers a full one year warranty on the tranny so they will be looking at it, but I am trying to figure out what cause the problem.
As far as the source of the pressure problem, could be anything. Bad piston seals, VB gasket blowout, pump, etc.
Could be simple too - have you checked the ATF on level ground with the engine running? Fluid level is critical. Also, it should look like cranberry juice, not prune juice, and not smell burnt.


