727 pop out/slip issue..

[340Duster247]

Hey guys so here's a new problem,
When the car is cold and leaving the garage , it shifts into reverse or drive just fine. You can feel it bang. It rolls a little bit, then nothing. Acts like it's in neutral, untill you Rev it a bit then it bangs back in and it's good from there on out.
The fluid level is fine. The trans is only 1 season old from last rebuild. The convertor was also new at time of rebuild Frank Lupo 9.5.
Last season it never had this problem. After I did a engine swap last winter and got the car out this summer is when the issue started happening.
The only other difference is I switched from B&M trick shift fluid (type F) to TCI trans fluid.
Thanks guys.

 

[pt70]

Try this. Start the car and shift it into neutral. Wait 30 seconds. Then drive it.

 

[CudaFactHackJob]

What is your exact fluid level with the motor running; in NEUTRAL?

 

[340Duster247]

What is your exact fluid level with the motor running; in NEUTRAL?

Just A little above the full line.

 

[CudaFactHackJob]

Does it bang back in for both drive and reverse?

 

[340Duster247]

Does it bang back in for both drive and reverse?

Yes

 

[CudaFactHackJob]

Did you check both sides of the stick ?

 

[340Duster247]

Did you check both sides of the stick ?

Hmmmm, that's a good question...I can't remember. I'll have to double check.

 

[CudaFactHackJob]

The fluid runs back down out of the converter at night and goes up the dipstick tube, It runs down when the converter charges in neutral, but still clings to the inside of the tube; so when you wipe off the stick and re-insert it, it picks up some fluid from the inside of the tube where it's been clinging.