Turbo 350 Pressure
 

I hooked it up a transmission pressure gauge to the yellow port in this picture. https://flic.kr/p/JmSzfb

At idle I have 0 psi. When revving it up in neutral i got it up to 150psi and in drive and reverse I got it to about 75psi all at around 4000rpm. Does this pressure seem low? Or do I have another issue going on here?



Here is the back story- I have a 68 firebird with a 400 and a turbo 350 trans in it. I swapped one 400 for another and did the torque converter at the same time. After doing this now the trans started kicking out of 3rd gear when the car got hot(15 mins+ of driving). Going into neutral then to drive would put it back into 3rd. Disconnected the vacuum modulator(old engine produced little vacuum) drove it to a car show and it was shifting better manually but still kicked out of 3rd once. When we went to leave the show the trans wasn't shifting at all now and when you put it in reverse you have to rev it up before it moves.

If you have zero line pressure at idle, you have s serious problem. Are you connected to the correct pressure port? There is no picture here.

https://c3.staticflickr.com/8/7377/2...5a6b3206_z.jpgIMG_1041 by Jacob Marquis, on Flickr

Maybe this will work if not https://flic.kr/p/JmSzfb

https://c3.staticflickr.com/8/7377/2...5a6b3206_z.jpgIMG_1041 by Jacob Marquis, on Flickr

Heres a functional picture

Pulled the pan and found some gold... And a bolt from the valve body just sitting there...

https://c5.staticflickr.com/8/7445/2...4b698488_k.jpgTurbo 350 Trans pan by Jacob Marquis, on Flickr

https://c5.staticflickr.com/8/7445/2...4b698488_k.jpgTurbo 350 Trans pan by Jacob Marquis, on Flickr

Check your governor. I can't talk to the pressure at the ports, but I have had an issue where shifts occurred later, and didn't want to keep it in 3rd. One of the flyweights on the governor had come loose and wasn't working right.

Governor will not cause low line pressure.

Good to know. But I have had similar shifting symptoms, and a governor is relatively easy access.

But in this case it would be a total waste of time.