lt170chevelle

iTrader: (2)

I have a 98 4l60e that just started having an intermitent 4th gear loss. Sometimes its totally not there and sometimes its there and holds well.
Also has an intermittent loss of all drive including reverse. Im thinking the pump could be the culprit , but wanted somebody elses opinion before i tear it down for a rebuild. Any advice and help with points of intrest would be very appreciated. I also noticed when 4th is there it shifts good and holds well but somtimes fades like its losing clutch/piston pressure.
Mako

performabuilt

iTrader: (25)

I would not think its the pump I would remove the pan and see whats in there and loss of all gears if the fluid is full is a serious mechancal issue im afraid.

lt170chevelle

iTrader: (2)

I forgot to mention that when all gears are lost..if i turn the motor off and then restart the gears are there again..almost as if a stuck valve or debri clog?? does that sound likely?

performabuilt

iTrader: (25)

Sounds like the filter is clogged with debris from some sort of failure.