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Discussion Starter · #1 · (Edited)
im working on a family members 04 envoy xuv. i replaced the shifter bushing. i verified the linkage is working properly and moving.

depress brake. start ignition. idle. release parking brake. shift lever into drive. vehicle in drive. idle rpm slightly changes. release brake. press gas. rpm increase. vehicle does not move. all gears R N D 3 2 1 not moving.

engine revs freely in gear. does not seem to be under load.

advice on trouble shooting would be appreciated.
 

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NOTE - ALL TESTING WILL REQUIRE USE OF THE IGNITION KEY - PREFERABLY WITH PERMISSION OF THE VEHICLE OWNER

TEST #1}
► Start engine (using key as noted above) ... place transmission quadrant into DRIVE and quickly shift back into PARK again.
a) IF THERE ARE horribly bad noises or LOUD clunking/thunking/grinding GOTO TEST #2
b) There are no oddball noises (perhaps a mild to moderate "thunk") ---> THIS IS NORMAL - GOTO TEST #4
TEST #2}
► With or without engine running, release PARKING Brake with the transmission in PARK.
► Try to push vehicle by hand (get help if you're feeble)

c) Does the vehicle move? GOTO TEST #3
d) Does the vehicle refuse to move? GOTO TEST #4

TEST #3} Requires the help of a TRUSTED friend
► Start engine and with whomever you've assumed to be your 'trusted friend' in driver's seat, place your head underneath the vehicle so that the rear driveshaft (at least) can be readily seen.
► Have so-called "trusted friend" alternately place transmission quadrant in
DRIVE then REVERSE without actually moving the vehicle much at all.
a) Do you notice ANY (read: 360°) rotation, revolving (spinning? twisting?) of the driveshaft? GOTO RESULT #1
b) Do you notice NO motion at all with the driveshaft? GOTO TEST #5
c) Can you hear any strange sounds of the driveshaft attempting to move? It can be subtle sounds. Listen carefully. If so, GOTO RESULT #2
TEST #4}
► Jack up either rear wheel and try to turn that same wheel by hand.
a) It turns ---> you're so-o-o-o screwed!​
b) It will not turn (this is good) -> SEE RESULT #2»4 & RESULT #2»5​
RESULT #1
Any or all of the following possibilities can exist:
»1 - One or both your rear wheels are off the ground.​
1a) check to see if your wheels/tires have been stolen and your car is on bricks or jack stands.​
1b) did you even HAVE a rear driveshaft?​
1c) you don't recognize what a driveshaft is GOTO HELPLESS #1
»2 - You've destroyed some critical part of your rear differential.​
»3 - You have a broken rear axle; either one --- or both (inside the housing)​
»4 - Somehow you lost your driveshaft - or it was stolen.​
»5 - You blew a u-joint and the driveshaft either ~​
(a) fell out long ago ("What was that funny noise?")​
(b) is still hanging from the transfer case but not attached to the differential companion flange.​
(c) when the driveshaft blew, it also took with it --- or: broke --- the tailcase off the transfer case and you've slyly noticed that even with the ATF having been lost, so is the latter 60% of your transfer case.​

RESULT #2
»4 - The rear brakes are seized (see NOTE 1A) + (see NOTE 1B)
»5 - The PARKING BRAKE is applied -- and it really works good! (see NOTE 1B)
»6 - Somehow both sets of rear axle bearings have seized. (highly unlikely) (see NOTE 1D).
»7 - The parking brake cables have both rusted and seized and won't release. (see NOTE 1C)

NOTE 1A -> This may be from a defective master cylinder NOT releasing the hydraulic pressure in the rear, but not limited to just the rear - brakes.​
NOTE 1B -> There are TWO brakes in the rear brake system if you also have rear disc brakes (eg: 4 wheel disc brakes).​
The second brake system, called the "PARKING BRAKE" [which is not an EMERGENCY BRAKE] is inside the dual-brake disc/drum assembly.​
Using the parking brake does NOT utilize the service rear disc brake system and vice-versa.​
NOTE 1C -> This is a common problem with vehicles driven in salted roadways and from users (drivers) failing to use the parking brake each time they park the vehicle.​
The PARK position in the transmission is NOT sufficient to hold a vehicle and it is secondary to the PARKING BRAKE anyway.​
NOTE 1D -> There is a very heavy (@90-weight) differential-gear oil in the hou$ing to keep thing$ lubricated. If it'$ mi$$ing, all $ort$ of bad thing$ can will happen. GOTO HELPLESS #1 and/or HELPLESS #2 --- your choice.
HELPLESS #1
»1 - You have no idea of the things that go "whizz' and 'whirl' and 'bump' inside/under a car and should buy new cars every 3 years so you don't have to work on them and leave all the warranty work to the dealership.
»2 - You are a 'user' and not an 'understander' or 'one of great mechanical ability' and should walk or ride a horse where you need to go. You are baffled by the ignition key.
»3 - Feed-shoe-curry-pet the horse if you chose that form of transportation. Regularly.

HELPLESS #2
»4 - You are likely a pariah in society and should never breed, or marry and thereby not spread your DNA around.
»5 - You live in your parent's basement and should stay there. Please.
»6 - You're a "re-nester" and brought all your walking - crawling - cookie crumbling DNA In Diapers with you, and your current significant other.
PS - I'm old, older by the day - and I have lots of time to create posts like this.
Be warned!
I have a computer!
 

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Discussion Starter · #3 ·
Thank you. I haven't had time to jump on that and test it. I will go through and give it a go. I appreciate your help and response because it included a few things I didn't even consider like the drive shaft.
 

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My only quest is to help those who appreciate our assistance.

"Our" includes ALL the people here who spend their valuable time answering questions like yours.
 
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