Author Topic: 4 wheel drive problems in my 1990 chevy 2500  (Read 6318 times)

Offline plowking_90

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4 wheel drive problems in my 1990 chevy 2500
« on: February 12, 2008, 04:43:41 PM »
i know it dosnt belong here but i know someone can help me here, i went out to put my plow on today and my driveway had a little ice around my plow so i locked it in 4 wheel to make sure i can get onto it, but it didnt lock in, i checked all the fuses everything was ok so i changed a plug on the tranfercase and i heared it lock in, i moved the truck and the 4 wheel drive light went out and now i have nothing again i need some help............ snow storm coming tonight!!!!!

Offline VileZambonie

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Re: 4 wheel drive problems in my 1990 chevy 2500
« Reply #1 on: February 12, 2008, 04:48:16 PM »
It's called slow or no engagement of the front differential. It's a known problem with a known good fix. Post all of your trucks specs here and I'll post the service repair procedure for it. Basically the actuator fails to lock the front diff
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1974 GMC

Offline plowking_90

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Re: 4 wheel drive problems in my 1990 chevy 2500
« Reply #2 on: February 12, 2008, 04:57:59 PM »
1990 k 2500 ld 6 lug, 350 700r4 i beleive its a np 208

Offline VileZambonie

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Re: 4 wheel drive problems in my 1990 chevy 2500
« Reply #3 on: February 12, 2008, 04:58:32 PM »
You'll need your Axle codes off of your spid label

They will start with Z and then just use the part # below


File In Section: 4 Drive Axle

Bulletin No.: 76-43-01A

Date: September, 1998

Subject:
Slow or no Engagement of Front Axle when 4WD is selected (Replace Front Axle Actuator)

Models:
1988-97 Chevrolet and GMC K Models
excluding 1988-93 Models over 8500 # GVW

This bulletin is being revised to add information to the Service Procedure, add a new part number, and include schematics. Please discard Corporate Bulletin Number 76-43-01 (Section 4 - Drive Axle).

Condition

Some owners may comment that the colder the outside temperature is, the longer it takes for the front axle to engage when 4 wheel drive is selected, or the front axle does not engage.

Cause

The front axle engagement actuator is a thermally activated component. Because of this characteristic, the time required for the actuator to complete 4 wheel drive engagement is extended as the temperature drops.

Correction

Replace the front axle actuator and include the applicable wiring harness kit. Refer to the Parts Information in order to determine which wiring harness kit is needed.

1996 model trucks with a build date on or after January 2, 1996 are considered as "961". If the build date of the truck is unknown, verify the 3 character "axle code" on the front axle label in order to determine which wire harness to order.

This new actuator uses a motor to engage the front axle and is not affected by temperature. On 1988-93 models with a GVW rating over 8500$, the new actuator cannot be installed and the thermal actuator will remain the service part.






Parts Information

P/N                     Description             Qty

26060073        Actuator Asm, Frt Drive Axle     1
22510339        Fastener                         1
15313272        Harness, Jumper (Z Splice)       1
                (86-93 K1-3)

Parts are currently available from GMSPO.

 
 
  
 


Warranty Information

Some owners with actuators that are operating as designed (5-30 seconds engagement time) may choose to upgrade to the fast actuator at their own expense. The fast actuator is a new product enhancement and should not be used to replace actuators that are operating as designed.

,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

1974 GMC

Offline VileZambonie

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Re: 4 wheel drive problems in my 1990 chevy 2500
« Reply #4 on: February 12, 2008, 05:01:27 PM »
Service procedure: I can email you the schematics if you want them too but I do't feel like hosting and posting since they show up resized and unreadable anyway.

1. Remove the front differential carrier shield, if equipped.
 
2. If necessary, clean the axle housing in the area around the existing actuator. Disconnect the actuator's electrical connection at the front axle housing.
 
3. Remove the front axle actuator by unthreading the actuator from the axle housing.
 
4. Install the spacer from the wiring kit into the axle tube with the flat side seated against the shift fork.
 
5. Install the actuator motor and tighten until the shoulder of the actuator seats against the axle tube.
 
 Important : If binding occurs before the actuator is seated, remove the actuator and reseat the spacer by pushing on the spacer with a screwdriver. Then reinstall the actuator.

On K3 Models with the cast iron axle tube, there may be a casting burr which may contact the edge of the actuator. This should not create a concern and the actuator should seat against the axle tube. If this contact remains a concern, use a die grinder in order to remove the burr.
 

 
 
 
 


6. Connect the service harness connector to the actuator and connect the 2-pin connector to the mating connector at the axle. For 1994 to current models, in the case of a complete axle replacement, refer to Figure 1.
 
7. Route the wiring harness along the existing harness on the right side of the vehicle. Route CKT 241 (BRN) over the top and to the left of the transmission. Secure the harness using plastic ties.
 
8. For 1995-97 interim vehicles, locate the 4-wire connector (C120) on the left side of the transmission. Splice the BRN wire of the actuator harness into cavity D of CKT 241 (BRN) on the engine side of connector C120. Follow the splicing procedure described in Section 8A (Electrical Diagnosis Repair Procedures) of the applicable Service Manual.
 
 Important :The new Fast Axle Actuator requires only 1 splice.
 
 
 
 
 

 
 
 
 

 
 
 
 


^ For 1993 and prior vehicles, splice into CKT 50 (BRN) between connector C152 and GT101 (Figures 2, 3, 4).
 
 
 
 
 

 
 
 
 


^ For 1994 vehicles, splice into CKT 50 (BRN) between connector C152 and P101 (Figures 5, 6).
 

 
 
 
 


^ For 1995-97 vehicles, splice into CKT 241 (BRN) between connectors C120 and C100 (Figure 7).
 
 Notice :Connections must be water tight in order to prevent water from entering the circuit and causing damage to the components.
 
9. On K3 models, install the delay relay, included as part of the wiring harness kit, at the engine side of the bulkhead, adjacent to the existing relay. Mount the new relay with self-drilling fastener, P/N 22510339. Route and secure the relay wire harness behind the right oxygen sensor heat shield.
 
10. Verify system operation. When shifting the transfer case, you should hear the actuator motor operate.
 
 Important :This relay incorporates a 5 second delay for the front axle to engage in order to allow the transfer case synchronizer to energize.

For 88-93 vehicles, if the axle has to be replaced, use jumper harness P/N 15313272. CKT 1695 (BLK/WHT) fits into cavity A of the fast actuator. The circuit includes the cable seal and the terminal pin. This circuit plugs into the 5-pin axle actuator connector.
 
11. Do the following steps in order to install jumper harness P/N 15313272:

a. Locate the axle actuator 5-pin connector on the service actuator wiring harness and remove the TPA.
 
b. Remove and discard the cavity plug from cavity A.
 
c. Install CKT 1695 lead (BLK/WHT) from the jumper harness that has the cable seal and terminal into axle actuator connector cavity A.
 
d. Reinstall the TPA on the 5-pin connector.
 
e. Install the service actuator harness 5-pin connector into the axle actuator.
 
f. Connect jumper harness 2x2 connector into the existing vehicle 4WD mating connector.
 
g. Strap the jumper harness and the service harness to the tab on the axle tube.
 
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

1974 GMC

Offline plowking_90

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Re: 4 wheel drive problems in my 1990 chevy 2500
« Reply #5 on: February 12, 2008, 05:03:29 PM »
when i lock the shifter in the 4 wheel indicator dosnt light up im pretty sure the acuator works, when i changed the plug i desribe earlyer it on the top of the transfercase i locked riht in to 4 wheel then i moved the truck and it went out

Offline VileZambonie

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Re: 4 wheel drive problems in my 1990 chevy 2500
« Reply #6 on: February 12, 2008, 05:06:42 PM »
Is the front drive shaft turning? If so, perform the above procedure. If not fix your shift linkage.
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

1974 GMC

Offline plowking_90

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Re: 4 wheel drive problems in my 1990 chevy 2500
« Reply #7 on: February 12, 2008, 05:10:43 PM »
the drive shaft is turning but my 4 wheel drive isnt turning on im goona run to the parts store ans se if i can get what i need thanks for the help

Offline VileZambonie

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Re: 4 wheel drive problems in my 1990 chevy 2500
« Reply #8 on: February 12, 2008, 05:13:45 PM »
Make sure you get the correct actuator and harness if necessary based on your axle code.
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

1974 GMC

Offline plowking_90

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Re: 4 wheel drive problems in my 1990 chevy 2500
« Reply #9 on: February 12, 2008, 05:19:01 PM »
where do i find the axle code?

Offline VileZambonie

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Re: 4 wheel drive problems in my 1990 chevy 2500
« Reply #10 on: February 12, 2008, 05:20:02 PM »
The Z codes. look in the glove box. Post them here
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

1974 GMC

Offline plowking_90

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Re: 4 wheel drive problems in my 1990 chevy 2500
« Reply #11 on: February 12, 2008, 05:32:01 PM »
zq2
zq3

only z #'s in the glove box

Offline VileZambonie

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Re: 4 wheel drive problems in my 1990 chevy 2500
« Reply #12 on: February 12, 2008, 05:41:35 PM »
so here is what you need then

P/N                     Description             Qty

26060073        Actuator Asm, Frt Drive Axle     1
22510339        Fastener                         1
15313272        Harness, Jumper (Z Splice)       1
                (86-93 K1-3)
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

1974 GMC

Offline plowking_90

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Re: 4 wheel drive problems in my 1990 chevy 2500
« Reply #13 on: February 12, 2008, 05:48:44 PM »
what is the fastner and the harness jumper do you have pics cant find any

Offline VileZambonie

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Re: 4 wheel drive problems in my 1990 chevy 2500
« Reply #14 on: February 12, 2008, 06:14:21 PM »
The new actuator is not a wax pellet so it requires a replacement jumper harness.  It's pretty self explanatory when you get the parts plus I believe it comes with the updated instructions.
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

1974 GMC

 


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