2001 4wd

ddubuque
0

Asked by ddubuque Feb 15, 2012 at 09:32 AM about the 2001 Chevrolet Suburban LT 1500 4WD

Question type: Maintenance & Repair

I have a 2001 Suburban with 140K miles. Just recently it stopped shifting into 4wd. When I press any 4wd mode, the switch just blinks. I can hear the motor on the middle transfer case engage. Is there a way to test the actuator? It seems like the switches on the dash are doing their job, and the transfer case motor is also. Would like to confirm actuator is bad. There are no check engine lights on, or service 4wd lights on. Thanks!

1 Answer

Eric Fritz
725

I've had a similar issue with my 01 burb, first off let's go over how the whole system works. The switches on the dash send a signal to the control module that then actuates either the encoder motor on the Tcase (the one that engages the clutches and shifts the range gear, on the front/bottom of the Tcase), it also sends a signal to the actuator on the front differential (on the front/top of the diff, about the size of a pop can) to engage the pinion gear to the axle shafts. If one of these motors fail, the other will still work, but no power will be transmitted to the wheels because the system is not fully engaged. A good home diagnostic test is to see if the front is trying to lock in by turning the vehicle to run, but don't start it. Then have helper press 4hi while you listen under the vehicle to see which one is working, and which one isn't, both should attempt to shift at this time. Since there is no service 4x4 light on, I would guess that your front actuator failed, but be sure to fully diagnose the situation before you go throwing parts at it because a front actuator is $150 and an encoder is $250 :( If you really want to be sure (this is what I'd do) First change the front diff and Tcase fluid (80w90 up front, synthetic Dex6 ATF in the Tcase, 2 quarts or so each) then, if that doesn't help, take the front driveshaft out (mark it's orientation on the front yoke) and shift into 4x4 with the engine off in run mode, now grab the front yoke and try to twist it, if it's locked into the wheels, it engages, now shift out of 4x4 to see if it disengages. Next, try to twist the driveshaft on the Tcase, it will be very hard to turn even if it is disengaged because the clutches always drag, see if it locks to where you can't turn it when the 4x4 is engaged, then you'll know if the encoder works or not. MAKE SURE THE VEHICLE IS IN PARK WITH THE WHEELS BLOCKED! Hopefully this will help you troubleshoot the problem. Good Luck!

2 out of 2 people think this is helpful.

Your Answer

Add photo

Related Questions

  • 2001 chevy suburban service engine soon light 1 answer

    I have a 2001 Chevy Suburban. When I drive 70 or over the service engine soon light flashes. In the same drive it flashed 13 times and went off for about 2 to 3 minutes then flashed 49 times and pau...

    2001 Chevrolet Suburban LT 1500 4WD

    -

    Maintenance & Repair

  • abs and brake light on in 2001 suburban 2 answers

    abs and brake light come on everytime i drive vehicle. been in shop twice , so calle fixed by replacing module. cant get straight answer as why. also low coolant light stays on and it has coolant and...

    2001 Chevrolet Suburban 1500 4WD

    -

    Maintenance & Repair

  • 2001 suburban power door lock fuse blows when unlock is pressed 1 answer

    2001 Chevrolet Suburban LT 1500 4WD

    -

    Maintenance & Repair

  • I have a 2001 Suburban. Radio quits and then starts working again 2 answers

    Radio quits and then starts working again - fades in and out. Front to back speakers. I have changed radios, cleaned connections? It has a factory external amp. Could that do this?

    2001 Chevrolet Suburban 1500 4WD

    -

    Maintenance & Repair

  • engaging 4wd in 1991 v1500 2 answers

    Hi I have a 1991 4wd suburban. Is there anything special about engaging the 4wd? I have had a friend tell me that i need to be stopped, have the tranny in neutral and then shift into 4wd - then switch...

    1991 Chevrolet Suburban V1500 4WD

    -

    General

Search Chevrolet Suburban Questions

Chevrolet Suburban Experts

#1 Eric Fritz
Eric Fritz
Reputation 650
#2 John Saffrahn
John Saffrahn
Reputation 440
#3 Tom Demyan
Tom Demyan
Reputation 380
View All

Related Models For Sale

Used GMC Yukon XL"
137 Great Deals out of 5,349 listings starting at $2,488
Used Chevrolet Tahoe"
493 Great Deals out of 25,308 listings starting at $1,955
Used Ford Expedition"
346 Great Deals out of 15,476 listings starting at $2,250
Used GMC Yukon"
192 Great Deals out of 8,205 listings starting at $2,350
Used GMC Yukon Denali"
96 Great Deals out of 7,694 listings starting at $9,490
Used Cadillac Escalade"
174 Great Deals out of 5,853 listings starting at $3,995
Used Chevrolet Silverado 1500"
1,588 Great Deals out of 138,412 listings starting at $1,500
Used Lincoln Navigator"
80 Great Deals out of 4,737 listings starting at $2,900
Used Toyota Sequoia"
106 Great Deals out of 3,859 listings starting at $2,900
Used Ford Excursion"
22 Great Deals out of 641 listings starting at $2,693
Used Ford F-150"
2,076 Great Deals out of 109,817 listings starting at $1,350
Used Chevrolet Silverado 2500HD"
411 Great Deals out of 30,182 listings starting at $2,725

Used Cars For Sale

2015 Chevrolet Suburban LT 1500 4WD For Sale
22 Great Deals out of 2,452 listings starting at $44,500
2014 Chevrolet Suburban LT 1500 4WD For Sale
181 listings starting at $32,500
2013 Chevrolet Suburban LT 1500 4WD For Sale
6 Great Deals out of 127 listings starting at $26,900
2012 Chevrolet Suburban LT 1500 4WD For Sale
6 Great Deals out of 152 listings starting at $21,900