Parking pawl question, Where is it in the tranny? (1 Viewer)

[Rusty Marlin]

I ask because I lifted up DS font wheel and my truck stated to leave! I was not expecting that. I've worked on a pile of US 4X4's and if they are in park you can do anything you want to the front end. Because of the VC for the all wheel drive I figured the LX would be the same as any other truck. Wrong. So where is the parking pawl and what does it engage? I gathered from my searches that was normal, so what happens if I lift a rear wheel? I didn't feel like repeating the experiment. But now I know with the the LX, always chock the wheels and set the parking brake.

 

[inkpot]

Has nothing to do with the transmission and Park. It is all due to the transfercase design. When the CDL is not locked, loose traction on any one wheel and all the power/traction goes to that wheel.

 

[BILT4ME]

I ask because I lifted up DS font wheel and my truck stated to leave! I was not expecting that. I've worked on a pile of US 4X4's and if they are in park you can do anything you want to the front end. Because of the VC for the all wheel drive I figured the LX would be the same as any other truck. Wrong. So where is the parking pawl and what does it engage? I gathered from my searches that was normal, so what happens if I lift a rear wheel? I didn't feel like repeating the experiment. But now I know with the the LX, always chock the wheels and set the parking brake.

@inkpot is correct.

One way you can offset that is to place the T-Case in low range and make sure the CDL light comes on on the dash, indicating the CDL is locked. That makes it so the front and rear axles are "connected" through the t-case.

I thought that was wrong , too, so I tested it by pulling the front end onto a pile of snow in the parking lot, making sure my rear axle stayed on pavement. I stopped, kept it in high range, then started to accelerate until the wheels started to spin and only ONE FRONT tire would spin. As I accelerated harder, I could feel the VC start to engage, but it was a bit jerky and felt totally wrong with the heavy throttle.

I moved the t-case to low range, got the CDL light, then started to accelerate, and immediately drove up and over the snow pile.

Now, if I park on a hill, I engage the CDL before I stop (I did the pin 7 mod and added a separate switch), then I feel more comfortable placing it in park and even using the parking brake.

 

[ProjectsNMotion]

But now I know with the the LX, always chock the wheels and set the parking brake

That's not specific to the LX450, you should be using wheel chocks and setting the parking brake whenever you're lifting any vehicle.

 

[Rusty Marlin]

All right Mr. Safety, we get the point. Obviously you don't put any part of you under a vehicle with out chocks and stands and I also throw the wheel I took off under the frame just in case the stand gives out. But then I'm paranoid about getting squished.
But do you honestly chock the wheels on any other vehicle when you just pop one up a 1/2 inch or so to check for bearing play and king pin or steering knuckle play. I never have, not until I met a Land Cruiser drive train.

This critter's got some eccentricities I'm still learning about. Its a neat vehicle, but there's some weird too.

I'm glad to know about the T-case trick, because I got to thinking about changing tires in less than ideal conditions, I've never carried wheel chocks in a vehicle, never needed too. This is the only vehical I have ever worked on that tries to leave on its own if you pick a wheel off the ground when in park if its not on level ground. I need to go re-read the owners manual, not entirely sure it covered that.

 

[BILT4ME]

All right Mr. Safety, we get the point. Obviously you don't put any part of you under a vehicle with out chocks and stands and I also throw the wheel I took off under the frame just in case the stand gives out. But then I'm paranoid about getting squished.
But do you honestly chock the wheels on any other vehicle when you just pop one up a 1/2 inch or so to check for bearing play and king pin or steering knuckle play. I never have, not until I met a Land Cruiser drive train.

This critter's got some eccentricities I'm still learning about. Its a neat vehicle, but there's some weird s*** too.

I'm glad to know about the T-case trick, because I got to thinking about changing tires in less than ideal conditions, I've never carried wheel chocks in a vehicle, never needed too. This is the only vehical I have ever worked on that tries to leave on its own if you pick a wheel off the ground when in park if its not on level ground. I need to go re-read the owners manual, not entirely sure it covered that.

All I ever drove to this point were older Chevy and International trucks with gear-driven or Chain-driven transfer cases and lockout hubs.
I NEVER had to worry about having it roll away from me or having it slide down a hill because one wheel was on ice.

This scared the crap out of me and made me move the CDL switch (repurposed hazard switch) and pin 7 mod to being an urgent priority.

I frequently park on a steep hill with wet grass (sprinklers) at my place of work (because the parking lot is very full and I get there late....and because I can...) so before I go up there, I push the CDL, then when I get set where I want to be, I put in park, then set the parking brake, then let off the brake pedal.
Hopefully it is still in the same place at the end of the day.......

 

[ProjectsNMotion]

All right Mr. Safety, we get the point. Obviously you don't put any part of you under a vehicle with out chocks and stands and I also throw the wheel I took off under the frame just in case the stand gives out. But then I'm paranoid about getting squished.
But do you honestly chock the wheels on any other vehicle when you just pop one up a 1/2 inch or so to check for bearing play and king pin or steering knuckle play. I never have, not until I met a Land Cruiser drive train.

This critter's got some eccentricities I'm still learning about. Its a neat vehicle, but there's some weird s*** too.

I'm glad to know about the T-case trick, because I got to thinking about changing tires in less than ideal conditions, I've never carried wheel chocks in a vehicle, never needed too. This is the only vehical I have ever worked on that tries to leave on its own if you pick a wheel off the ground when in park if its not on level ground. I need to go re-read the owners manual, not entirely sure it covered that.

There's no need for sarcastic name calling. The parking pawl only locks the output of the transmission. If there are all open differentials between the transmission and the drive wheels, lifting any single drive wheel off the ground will allow it to roll forward while in park. Always set the parking brake when lifting a wheel off the ground, including changing a flat tire, because the parking brake prevents both rear wheels from turning. Wheel chocks would be better, but setting the parking brake and locking the center differential will suffice.

 

[Rusty Marlin]

The parking pawl only locks the output of the transmission. If there are all open differentials between the transmission and the drive wheels, lifting any single drive wheel off the ground will allow it to roll forward while in park.

And that is the Golden Nugget of information! Now it makes sense; I was struggling with the T-case driving both sets of axles with an open diff between them vs American trucks that only drive the front axle off the T-case.
Thank you.

 

[Tools R Us]

Not really unique, on a 2WD, lift either of the drive wheels and it can roll. Park is for parking, more is needed for lifting.

 

[mudgudgeon]

But do you honestly chock the wheels on any other vehicle when you just pop one up a 1/2 inch or so

Yes every time, front or back wheel, doesn't matter. Takes seconds to chock a wheel vs being squished, or having a car shift, fall of a jack and damage something.