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2001 Silverado Rough 1-2 Shift...


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#1 chrohm

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Posted 30 May 2003 - 07:58 AM

Do I just take it into the dealer for this? It has been this way since I've had my truck but it seems to be getting worse, and annoying now that I drive slower. If I give it a good amount of gas it shifts fine...Only when taking off slow it seems like it's falling in hard.

Help!
Thanks

#2 asepgrad98

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Posted 30 May 2003 - 06:31 PM

this is the very same problem that caused me to search out this forum many moons ago... :confused:

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 24C (75F).
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 Nm (80 lb in).

Connect the negative battery cable. Tighten
Tighten the battery cable retainer to 17 Nm (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.
2002 Silverado 5.3L 2WD Ext. cab
Escalade door handles
Amber DRLs
15.61@87mph stock

#3 Silverstanger

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Posted 30 May 2003 - 08:43 PM

my 94 Z-71 with 4L60E does exactly the same thing and when I am on the gas it seems to do it less.. real hard sometimes and others normal.

Same cause?? It was rebuilt in January according to the paperwork and previous owner.

#4 Silverstanger

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Posted 30 May 2003 - 09:16 PM

I checked the wires going to the actuator and found a good site with info on how it works..

I have 12 Volts DC going to it when 4L or 4H is engaged. the 4WD fuse also removed the power to it, so I know that is good.


The actuator reads 600K ohms for those who know how to read them..

I don't know if that is good or bad.

how about some suggestions on what to replace the actuator with.

thanks

#5 Silverstanger

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Posted 30 May 2003 - 09:32 PM

Using the equation for voltage.. i would think that I need an few ohms or less to get a few amps to show for using the 25 amp fuse.

12V/600K=.00002 Amps current..

I doubt that would heat anything so I will say the actuator is bad now.

#6 BigGreen

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Posted 02 June 2003 - 10:30 PM

GM has a PCM software update that helps this problem as well

#7 chrohm

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Posted 03 June 2003 - 12:33 AM

it's very weird...sometimes it shifts perfectly...other times it just acts weird

#8 FloridaZ

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Posted 03 June 2003 - 08:00 AM

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)

Is 02-07-30-030 the TSB number?
05 2500HD 4x4 ECSB Duramax, SpeedLiner, 265 Nittos
For Sale
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#9 seadoons

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Posted 03 June 2003 - 08:17 AM

My '02 has the same problem...the new solenoid is on order. The part is on "national backorder" and it has been over 3 weeks, and still nothing. Mine has the same symptoms as ya'll's, doesn't do it all the time, sometimes it shifts perfectly, but others it just falls into 2nd. Really annoying, especially since the entire truck shutters when it does it. Good luck to everyone with the problem... :lol:
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2002 Chevrolet Silverado Extended Cab Z71 LS 5.3L - Forrest Green

Factory Installed Options: Autotrac, limited slip diff., painted fender flares, trailer towing package

Aftermarket Additions: BFG 285/75/16 All-Terrains, 16x8 Chrome American Racing Python Wheels, Bilstein 5100 Shocks, Westin nerf bars, manik brush guard, KC lights on the guard, spray in bedliner, Delta chest-style tool box, 2 10" Xtant subs in a thunderform box, 20% tint for the front windows.

#10 chrohm

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Posted 03 June 2003 - 06:29 PM

so do I just give them the TSB number or what did you do?
I think I may try to get them to also fix the steering column rattle sound when turning in a parking lot...uggggh