Sponsored

Failing the 4H Test?

MHG

TRD Off-Road Premium
Active member
First Name
Mark
Joined
Jan 31, 2025
Threads
2
Messages
41
Reaction score
16
Location
Long Island
Vehicle(s)
2025 TRD Offroad
Got me 2025 Taco home. Live on Long Island so off-roading places are limited. Beaches open on April 1. Testing putting it into 4L and 4H Saturday. Did. It seem to disengage from 4H (although the 4H icon went out). Drove and heard a loud clunk on a the . Backed up and went forward all seams good.

Wanted to test my 4WD so went to a parking lot. Put the front wheels against the curb. Stepped on gas and felt a tone of resistance. Engage 4H and it feels the same. Engage 4L and it goes right up the curb effortlessly.

Guess my question is, is it possible for 4L to work and 4H to display its working but not actually engage? I would think it’s the same inside the front did, just a lower gear on the trans.

Again, all indications on the dash tell me it’s engaging. I may have had the traction control on so maybe that’s effecting the 4H.
Sponsored

 

BAQ717

TRD Off-Road
Well-known member
First Name
Brian
Joined
Nov 13, 2024
Threads
10
Messages
67
Reaction score
77
Location
Pennsylvania
Vehicle(s)
‘24 Tacoma TRD OR
Got me 2025 Taco home. Live on Long Island so off-roading places are limited. Beaches open on April 1. Testing putting it into 4L and 4H Saturday. Did. It seem to disengage from 4H (although the 4H icon went out). Drove and heard a loud clunk on a the . Backed up and went forward all seams good.

Wanted to test my 4WD so went to a parking lot. Put the front wheels against the curb. Stepped on gas and felt a tone of resistance. Engage 4H and it feels the same. Engage 4L and it goes right up the curb effortlessly.

Guess my question is, is it possible for 4L to work and 4H to display its working but not actually engage? I would think it’s the same inside the front did, just a lower gear on the trans.

Again, all indications on the dash tell me it’s engaging. I may have had the traction control on so maybe that’s effecting the 4H.
You’re overthinking it, my fellow Taco enthusiast. I’m sure it’s just fine, I believe it’s just a matter of gearing. Wait till those beaches open up and enjoy. Can’t wait to get mine on the sand sometime this summer.
 
OP
OP

MHG

TRD Off-Road Premium
Active member
First Name
Mark
Joined
Jan 31, 2025
Threads
2
Messages
41
Reaction score
16
Location
Long Island
Vehicle(s)
2025 TRD Offroad
Well I guess I can add some movement to the test. Although you would think the ADD is still engaging and disengaging the same differential .
 

Sponsored

Forest Moon

TRD Off-Road
Well-known member
First Name
Michael
Joined
May 26, 2024
Threads
2
Messages
62
Reaction score
45
Location
MA
Vehicle(s)
2024 OR Supersonic Red MT
You don't have to jump a curb to test the 4wd. Just drive around in a circle. Then on a straightaway, engage 4H and circle around again. There should be a lot of resistance when turning on pavement. You can do this at very slow speeds.
 
OP
OP

MHG

TRD Off-Road Premium
Active member
First Name
Mark
Joined
Jan 31, 2025
Threads
2
Messages
41
Reaction score
16
Location
Long Island
Vehicle(s)
2025 TRD Offroad
You don't have to jump a curb to test the 4wd. Just drive around in a circle. Then on a straightaway, engage 4H and circle around again. There should be a lot of resistance when turning on pavement. You can do this at very slow speeds.
That’s what I was doing g when I heard the gun shot pop. Trying to avoid doing that again.
 

Yotota

TRD Off-Road Premium
Active member
First Name
Zane
Joined
Oct 10, 2024
Threads
1
Messages
42
Reaction score
44
Location
SW WA
Vehicle(s)
24 TRD
The pop was probably the transfer case engaging or disengaging.

How I test modern 4 wheel drive trucks:

- Find a gravel parking lot.
- Drive in a circle in 2wd. Remember how it feels in that gravel.
- Switch to 4High. Wait for the light to stop blinking. If it takes more then 5sec, slowly roll forward in a slight turn until it engages.
- Once engaged, drive in a circle again. You'll feel the front end scrubbing against the gravel.
- Stop. Straighten the wheels, roll forward a little to unbind the drivetrain.
- Trans to neutral, switch to 4Low. Wait for the light to go solid again.
- Trans to drive, do another circle. Should feel like it did in 4High, but a lot slower and torquier.
- Stop. Straighten the wheels, roll forward a little to unbind the drivetrain.
- Have a locker? Time to test it. Push the locker button. Wait for the light to go solid. If it takes more than 5sec, slowly roll forward in a slight turn to get the rear wheels to spin at different speeds and align the diff splines.
- Drive in a circle. Your inner rear wheel should be spinning/hopping a bit on the gravel, and/or the outside rear wheel will be dragging a bit.
- Stop. Push the locker button. Wait 5sec for it to unlock.
- Roll forward slowly and slightly turn left/right to unbind the locker and allow it to pop loose.
- Stop. Straighten the wheels, roll forward a little to unbind the drivetrain.
- Trans to neutral, switch to 2High. Wait for the 4wd light to go out. You'll hear a clunk at the very least.
- Trans to drive. Roll forward slowly to make sure everything is disengaged. It may need a slight turn to let the transfer case disengage.
- The truck should be back to normal in 2wd high.
 
OP
OP

MHG

TRD Off-Road Premium
Active member
First Name
Mark
Joined
Jan 31, 2025
Threads
2
Messages
41
Reaction score
16
Location
Long Island
Vehicle(s)
2025 TRD Offroad
It probably was. It was so loude 3 of my neighbors came running out of their houses to see what hit.

Thanks for taking the time to type all that out. Gravel parking lots are about as common on Long Island as Politicians.

Ill Hit up Google earth to see if I can find one.
Sponsored

 
 






Top