Automatic clutch slipping/ not fully dis-engaging?

My girlfriend has a 94 and from what she's telling me, it wont shift out of third into fourth right away unless you really give it the beans and rev it into the 5k range! She says that when shes in the high rpms it doesn't shift for a minute or two, but after that, it's completely fine. I'm thinking it's an electrical issue but I've no idea. Any of you 4runner Guru's that can help would be greatly appreciated.

Also, the transmission has recently been flushed last week and has also had the filter replaced. It's also been rebuilt within the last 3 months.

 

Sounds like someone fucked up on the rebuild.

Hope it has a warranty.

 

Flush or drain and fill? What was going on with the rebuild?

 

The fluid level is the first place I would look.

 

x2. Check the fluid level. Also, why were you flushing a brand new transmission? Did you try the flush to remedy the problem or did the problem arise as a result of the fluid flush? If the problem was there before you flushed the transmission, then get the truck back to the shop that rebuilt it because they screwed it up.

 

Tranny was service about 3 months ago. Has a 6 month warranty so I think we will send it back pretty soon. Yes we did flush the tranny Last weekend so fluid is fresh and the level is where it needs to be.