automatic shift problem

I've got a 1997 Z28, the problem is that SOMETIMES (and i don't know exactly the circumstances) when i'm just kinda normaly come off the line, when the automatic transmission goes to kick it up into second it's not the normal shift... it's really hard and i feel like one of these times it's gonna give me whiplash, it's a very hard jerk forward. But it goes into gear and everything's fine after that. I have no idea for I'm not familiar with automatic transmissions, this is my first. If anybody has ANY ideas I'd appriciate it a lot. Thanks for any help.

Sounds like either an electrical problem or the valve body itself is defective.

You will need to have a shop look at this, unless you have all of the tools and diagnostic equipment there won't be much you can do for it.

There is one bulletin for the Valve body replacement and a long checklist for the symptons you described.

<H1>Slipping or Harsh 1-2 Shift</H1>
<TABLE WIDTH="100%" BORDER=1>
<A NAME="tab1-10224">
<A HREF="#tab1-10224">
<H4><FONT COLOR="#254164">Slipping or Rough 1-2 Shift</FONT></H4></A>

<TR>
<TH ALIGN="center" VALIGN="bottom" ROWSPAN=1><P>Checks</P>
</TH><TH ALIGN="center" VALIGN="bottom" ROWSPAN=1><P>Causes</P>
</TH></TR>
<TR>
<TD ALIGN="left" VALIGN="top" ROWSPAN=1><P>Valve Body Assembly&nbsp;(60)</P>
</TD><TD ALIGN="left" VALIGN="top" ROWSPAN=1>
<UL TYPE="BULLET">
<LI>Mislocated valve body to spacer plate checkball or checkballs.
</LI>

<LI>1-2 Shift valve train stuck due to sediment
</LI>

<LI>Gaskets or spacer plate incorrect, mispositioned or damaged
</LI>

<LI>1-2 Accumulator valve stuck or damaged
</LI>

<LI>Face not flat
</LI>

<LI>4-3 sequence valve stuck or damaged
</LI>

<LI>#1 or #8 checkball missing or mis-located
</LI>

<LI>1-2 accumulator valve bushing rotated 180&deg;
</LI>
</UL>
</TD></TR>
<TR>
<TD ALIGN="left" VALIGN="top" ROWSPAN=1><P>2-4 Servo Assembly&nbsp;(13-28)</P>
</TD><TD ALIGN="left" VALIGN="top" ROWSPAN=1>
<UL TYPE="BULLET">
<LI>Apply pin too long or too short
</LI>

<LI>2nd servo apply piston seal missing, cut or damaged
</LI>

<LI>Restricted or missing oil passages
</LI>

<LI>Servo bore in case damaged
</LI>
</UL>
</TD></TR>
<TR>
<TD ALIGN="left" VALIGN="top" ROWSPAN=1><P>2nd Accumulator&nbsp;(55-57, 104)</P>
</TD><TD ALIGN="left" VALIGN="top" ROWSPAN=1>
<UL TYPE="BULLET">
<LI>Porosity in 1-2 accumulator cover or piston
</LI>

<LI>Piston seal or groove damaged
</LI>

<LI>Nicks or burrs in 1-2 accumulator housing
</LI>

<LI>Missing or restricted oil passage
</LI>

<LI>1-2 accumulator piston spring not seated
</LI>

<LI>Rough finish in 1-2 accumulator bore in case
</LI>

<LI>A cracked 1-2 accumulator piston - allowing fluid to leak by
</LI>
</UL>
</TD></TR>
<TR>
<TD ALIGN="left" VALIGN="top" ROWSPAN=1><P>2-4 Band&nbsp;(602)</P>
</TD><TD ALIGN="left" VALIGN="top" ROWSPAN=1><P>Worn or mispositioned</P>
</TD></TR>
<TR>
<TD ALIGN="left" VALIGN="top" ROWSPAN=1><P>Oil Pump Assembly&nbsp;(4) or Case&nbsp;(103)</P>
</TD><TD ALIGN="left" VALIGN="top" ROWSPAN=1><P>Faces not flat</P>
</TD></TR>
</TABLE>