[GMCSID]

<H1>Transmission Oil Leak, Abnormal Knocking Noise Heard at Idle</H1>
<H1> (Diagnose and Repair as Requried) </H1>
<H1> #03-07-30-037 - (09/04/2003)</H1>


Transmission Oil Leak, Abnormal Knocking Noise Heard at Idle (Diagnose and Repair as Required)


2001-2003 Chevrolet Silverado 2500/3500 Series Pickup Models


2001-2003 GMC Sierra 2500/3500 Series Pickup Models


with Duramax® Diesel (RPO LB7) and Allison® 1000 Series Automatic Transmission (RPO M74)<A name=ss1-1378771><A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=1378771&pubid=297#ss1-1378771" target="_blank">
<H5>Condition</A></H5>


Some customers may comment that an abnormal knock noise is heard when the engine is running, or that there is an oil leak from the bottom of the converter housing.<A name=ss2-1378771><A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=1378771&pubid=297#ss2-1378771" target="_blank">
<H5>Possible Cause</A></H5>


The Plate, A/transmission Flex (Flexplate adapter plate) to converter mounting bolts may have loosened from engine/road vibration. Use the diagnosis procedure given in this bulletin to diagnose the vehicle for this potential cause.


<A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=1378771&pubid=297#ss5-1378771" target="_blank">
<H5>Parts Information</A></H5>



<H4>Important</H4>


The converter drain back kits contain six (6) new converter to flexplate attachment bolts. These bolts have an adhesive patch on the threads. These are a one-use bolt and must be replaced anytime they are removed.






<TABLE width="100%" border=1><T><T><T><T><T><T>
<T>
<TR>
<TH vAlign=bottom align=middle>


Part Number</TH>
<TH vAlign=bottom align=middle>


Description</TH>
<TH vAlign=bottom align=middle>


Qty</TH></TR>
<TR>
<TD vAlign=center align=middle>


88996718</TD>
<TD vAlign=center align=middle>


Kit, Converter drain back</TD>
<TD vAlign=center align=middle>


1</TD></TR>
<TR>
<TD vAlign=center align=middle>


29539580</TD>
<TD vAlign=center align=middle>


Pump Assembly</TD>
<TD vAlign=center align=middle>


1</TD></TR>
<TR>
<TD vAlign=center align=middle>


29541149</TD>
<TD vAlign=center align=middle>


Wear Plate, Pump</TD>
<TD vAlign=center align=middle>


1</TD></TR>
<TR>
<TD vAlign=center align=middle>


29538529</TD>
<TD vAlign=center align=middle>


Converter</TD>
<TD vAlign=center align=middle>


1</TD></TR>
<TR>
<TD vAlign=center align=middle>


97225899</TD>
<TD vAlign=center align=middle>


Plate, A/Trans Flex</TD>
<TD vAlign=center align=middle>


1</TD></TR>
<TR>
<TD vAlign=center align=middle>


97226124</TD>
<TD vAlign=center align=middle>


Bolts,</TD>
<TD vAlign=center align=middle>


8</TD></TR>
<TR>
<TD vAlign=center align=middle>


15704050</TD>
<TD vAlign=center align=middle>


Gasket, Transmission to Transfer Case. </TD>
<TD vAlign=center align=middle>


1*</TD></TR>
<TR>
<TD vAlign=center align=middle>


12378470


(1 quart)


(Canadian P/N 10952622 (1L)</TD>
<TD vAlign=center align=middle>


DEXRON® III Automatic Transmission Fluid</TD>
<TD vAlign=center align=middle>


12 L (13 quarts)</TD></TR></T></T></T></T></T></T></T></TABLE>





Edited by: hoot

 

[dmaxalliTech]

Beat ya to it!! Thanks Sid


Eric

 

[GMCSID]

Sorry, I looked but not hard enough. I have one of these I will be doing on Monday. I was amazed by the amount of parts to change. It's an expensive repair. You can just delete this.

 

[dmaxalliTech]

Sid, I would never delete info from a fellow Tech!!! You have to replace spring for drainback? ever done one? let me know if you have trouble


Eric

 

[dmaxalliTech]

DUH ME!! I just read the tsb again... That is expensive! Might better get a Trans Go kit to put in while your there!!


Eric

 

[GMCSID]

I have done one drainback kit and replaced a rear housing and C5 piston so far. I hope to get more into these since they have come off restriction.