Anybody knowledgeable of 700-R4?

[Jack Boelte]

I've got an '84 Suburban with the 350/700-R4.  When accelerating on the highway from 65 up, it feels like it's slipping.  When I let up, then ease into it, it feels right.

 

I have seen black stuff on the dip stick, slipping I'm sure.  Fluid was a little low, I haven't driven since I topped it off.  I had a good trans. shop take it apart about 2 years ago, they replaced the 4th gear band, said it was burned.  I had the shop adjust the TV cable, he seemed happy with it.

 

I suspect low pressure to the 4th gear band.  I think the torque converter lock up clutch is working good.  Is there a particular valve that may be leaking?  I have a Haynes transmission manual, it's typical of a Haynes manual...  leaves a lot out.:sneek:  Would a B&M shift kit be a good band aid?  Would it direct more pressure to 4th gear?

 

Thanks