So this is kinda weird, well to me anyway, I have a 700R4 out of a 93 LT1 Car, built with a Mega Monster kit according to the person I got it from which I believe to be true. In OD/4 from a dead dig WOT the tranny shifts at 4500ish RPM. Put it in D/3, WOT from a dig it will go to 5800 like it is supposed to. I am simply curious as to why. I assume it has to do with line pressure, I just though it was odd.

 

Odd yes my 4l60e shifts at 5800 in od and in D however i heard it was hard on a trans to run it hard in OD. Just to gun it in drive then slip it OD when necessary.

 

The 4L60E shift points are PCM controlled, not so in the 700R4 (4L60).

The line pressure should be the same with the shift selector in the OD or the D position. There may be an internal leak which is causing it to change at the governor. One main difference between the OD and D positions is that in D the over run clutches are engaged.

RBob.

 

A leak, super, would it be in the valve body or in the internals of the trans?

 

I have no idea, not familiar enough with how the fluid circuits and seals are. As for a valve body leak easy enough to get two new gaskets and R&R the VB. Be sure to check the old gaskets for push-out or a piece missing prior to puling them off whichever piece they are stuck too.

RBob.

 

Yea I may do that just because, it also does this odd thing when it down shifts from 3-2, it downshifts hard, but upshifting back to 2-3 it kinds lags, the RPMS don't snap down although the shift feels positive. Almost like the band isn't releasing or the clutches aren't applying fast enough, one or the other, I am thinking clutches. Going from 1-2, 2-3 it shifts perfectly though.