Transmission does not go into gear?

[wraith13]

I have a 98, ext cab, 4x4, 3.0L, auto tranny. Once in a while when the vehicle has not been used for awhile....it doesn't go into a gear....I can put in drive, rev, 4low, 4hi....nothing...so I put into Park for a few min and then it is fine, any ideas?....the fluid level is fine.

 

[mylittleblackbird]

That would indicate that the fluid is bleeding out of the system and it has to pump it back up. Does it shift without issues once it's going? When was the last time the fluid/filter was changed?

 

[wraith13]

it runs fine once it does go into gear.....no sign of a leak anywhere....I'm not sure when the fluid was changed last, I have only had the truck just over a year, and it is not used very much....John

 

[mylittleblackbird]

I'm referring to an internal leak. A fluid/filter change might not be a bad idea, but I can't promise it would improve the situation. It sounds like there isn't enough pressure to engage the clutch packs to generate any movement.

The reasons could be that a seal for the input clutch pack is worn out, or the fluid going to the pump is bleeding out of the system and it has to prime itself after sitting for an extended period. Perhaps other reasons exist, I am unsure. However the basics of the transmission require fluid pressure to engage the gears. No movement indicates no pressure.