<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
<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