ZF-4HP22 reverse slipping?
I have a 1995 NAS D90 with a ZF-4HP22 auto box installed. The auto box seems to be having a problem with reverse. It goes into reverse fine and will back up on flat surfaces, but under load the engine seems to rev higher than it should and feels sluggish (no real power at the wheels). If I brake and rev the engine in reverse it will easily hit 3000-3500 RPM while in forward gears it will slow the engine around 1800-2000 RPM. Does this mean the reverse clutch pack is slipping? Is there an adjustment or does it mean the auto box has a serious problem and needs replacement. All forward gears appear to work fine. This autobox is only 8 months old and has about 1500 miles on it. The fluid is a little dark but still has a red tint to it and does not smell burnt. Opinions? Anything I should try? Thanks.