clunk and stutters between 1st & 2nd

[Sierra20]

2002 GMC Sierra

I've had my clunking problem on here before and you all gave me great ideas on trying to get to the bottom of it. The noise still exists. Lately I've been noticing that my truck stutters when it shifts from 1st to 2nd gear. Sometimes it feels like it might do it from 2nd to 3rd. I don't know if it is slipping or what. No matter when I step on the throttle, it accelerates so I don't think it would be the tranny slipping. That stutter bothers the he** out of me. Anyone have this problem or know what could be causing this? I'm hoping it isn't my transmission going out, I leave for college in a month and can't afford to replace that.

 

Maybe this clunk and this "stutter" is a related problem.

Thanks

[fastdrvr23]

I had the 1st to 2nd shift stutter, and the dealer fixed it with a PCM update. I took the truck in, and they flashed the PCM and it went away immediately. If you're still in warranty it shouldn't cost a thing. They knew exactly what I was talking about when I described it, I'll check after work to see what they wrote on the warranty ticket.

 

There's a TSB about it somewhere around here, but I can't seem to find it searching...hmmm

 

Good luck!

[asepgrad98]

Transmission 1-2 Shift Shudder, Vibration, Slips, Chuggle (Install Generator Voltage Sense Circuit) #02-07-30-030

 

 

Transmission 1-2 Shift Shudder, Vibration, Slips, Chuggle (Install Generator Voltage Sense Circuit)

2001-2003 Chevrolet Silverado

 

2001-2003 GMC Sierra

 

with 4L60-E Automatic Transmission (RPO M30)

 

Condition

Some customers may comment that the transmission slips, a shudder, chuggle, or vibration is felt when the transmission shifts from first to second gear.

 

Cause

A 12 Hz electrical feedback from the charging circuit may be affecting the transmission pressure control solenoid, causing a fluctuation of the line pressure within the transmission.

 

Diagnostic Tip

Road test the vehicle under the following conditions:

 

Throttle position is less than 15 percent.

Engine coolant and transmission fluid are at full operating temperature.

The outside ambient temperature is warmer than 24°C (75°F).

If the condition is present, disconnect the generator 4 cavity connector (2 wires in the connector) and retest.

 

If the condition is no longer present, perform the correction listed below.

 

If the condition remains unchanged, the condition will not be corrected with this procedure. Look for other causes of the condition.

 

Correction

Install an external sense lead to the generator assembly. This is accomplished by adding a wire from the generator four wire connector to the generator output BAT terminal.

 

Disconnect the negative battery cable from the battery/batteries.

Slide the protective boot on the generator BAT terminal aside and remove the retainer and wire cable from the BAT terminal.

Unplug the generator 4-cavity terminal from the top of the generator.

Remove and save the orange weatherpack seal and CPA from the 4-way connector.

Using the proper terminal removal tool, remove the two wires from the 4-way connector.

Install a red cavity plug, P/N 12059168, into cavity "A" of the new 4-way connector, P/N 12186568.

Install the brown (Circuit 25) wire of the vehicle wiring harness into cavity "B" of the new 4-way connector.

Install the gray (Circuit 23) wire of the vehicle wiring harness into cavity "C" of the new 4-way connector.

Obtain a piece of 0.80 mm/18GA black wire, 254 mm (8 in) long.

Install a red terminal seal, P/N 12048086, and terminal, P/N 12048074, (crimp and solder) on one end of the new black wire.

Install the new black wire into cavity "D" of the new 4-way connector.

Reinstall the connector seal and CPA, from the original connector, to the new connector.

Plug the 4-way connector into the generator.

Route the black wire to the generator BAT terminal, sliding the wire into the small end to the output terminal boot, along side the generator output wire.

Crimp and solder the ring terminal, P/N 02977821, on the open end of the new black wire.

Place the generator output wire and the new black wire onto the generator BAT terminal and install the retainer. Tighten

Tighten to the BAT terminal retainer to 9 N·m (80 lb in).

 

Connect the negative battery cable. Tighten

Tighten the battery cable retainer to 17 N·m (13 lb ft).

 

Parts Information

Part Number

Description

Quantity needed for this repair

SPO Dealer Cost

J 38125

 

Kit Tray Location

Available from Kent Moore (approximately $12.50 per pkg)

 

12048074*

Terminal

1

$0.57

Tray # 2

50 per package

 

12059168*

Cavity Plug

1

$2.00

Tray # 3

25 per package

 

12048086*

Wire Seal, Red

1

$2.05

Tray # 3

25 per package

 

02977821

Ring Terminal

1

$1.50

Must be ordered from Parts.

N/A

 

12186568

Connector

1

$1.30

Must be ordered from Parts.

N/A

 

 

Part numbers shown above which have an (*) are found in the terminal repair kit, J 38125. They may be ordered either from GMSPO or SPX Kent Moore.

 

Parts are expected to be available 8-15-2002 from GMSPO.

 

Warranty Information

For vehicles repaired under warranty, use:

 

Labor Operation

Description

Labor Time

 

*N8505

Rewire Generator, 1-2 shudder

0.7 hr

 

*This is a unique labor operation number for use only with this bulletin. This number will not be published in the Labor Time Guide

[Sierra20]

What would it cost to get this problem fixed? My warranty is up.