WadeC

My 4l60e in my 94 just went out again,when I gave it gas to kick it from 4th to 2nd. I took it apart, and found everything looks good, but the forward drum flowered out and started slightly cutting into the case. Also,the sunshell is slightly flowered out. What causes just these parts to go? This is the 2nd time it has done this.

TeamTripp

What RPM is it shifting at and in what condition is the Foward Sprag? Your sprag may be slipping when you kick it down. If you don't already have it, get the Borg Warner 29 element sprag, and scuff the outer race w/ some emery cloth.

WadeC

Thanks for the input. I shift at 6700rpm. I will check the sprag closer tomorrow.

Automatics

If the input sprag is slipping, it will cause this. Replace the whole assembly with the late GM sprag assembly, it will come with everything you need, including a new input sun gear ($175.00), along with a new GM reverse input drum ($97.33) and a GM HD sunshell ($35.17). Let me know if I can be of help?

WadeC

I didnt see anything wrong with the sprag upon quick inspection today. One other major thing I didnt mention, was that when the trans went the this time, the seal around the outside of the pump started leaking badly. Too much line pressure?

Automatics

Too much line pressure will not cause this. Look at the sprag & inner race very closely, and if you are not sure what to check, take it to someone who does & you can trust. The drum & sunshell can only be ballooned by the sprag slipping, from what I have seen.

WadeC

Thanks for the help. The sprag locks one way and moves freely the other,but on the inside, there is a spot where you can see that it rubbed the springs underneath it. The outsides of the springs are rubbed flat. Is this from the type on sprag failure you mentioned or a result of the other damage?