Center differential explanation (1 Viewer)

[BILT4ME]

One more noob question since I have you all gathered here, what do the PWR/2ND buttons do?

You can search that as well.

It changes the shift patterns of the transmission.

PWR is like on the movie Mad Max, when Mel Gibson is chasing the bad guys, and he flips a switch on the shifter, then they cut to the blower engaging on the engine, then cut back to the rear tires smoking and speed dramatically increasing until he runs over the guy.


Yeah, not like that at all. It holds the gears a little longer so it shifts at higher RPM, a little higher on the torque curve.

The 2nd is for use in low range and in snow, so the trans starts out in 2nd gear instead of first so you don't get head snapping, tire spinning rage. That part is real if you floor it. In low range, from a dead stop on dry pavement, I can get a tire chirp in first, then when it shifts to 2nd, then to third in about 20 ft.

 

[undecided]

You can search that as well.

It changes the shift patterns of the transmission.

PWR is like on the movie Mad Max, when Mel Gibson is chasing the bad guys, and he flips a switch on the shifter, then they cut to the blower engaging on the engine, then cut back to the rear tires smoking and speed dramatically increasing until he runs over the guy.


Yeah, not like that at all. It holds the gears a little longer so it shifts at higher RPM, a little higher on the torque curve.

The 2nd is for use in low range and in snow, so the trans starts out in 2nd gear instead of first so you don't get head snapping, tire spinning rage. That part is real if you floor it. In low range, from a dead stop on dry pavement, I can get a tire chirp in first, then when it shifts to 2nd, then to third in about 20 ft.

I figured it was in the FAQ area someone else mentioned but I’m a bit of a boomer when it comes to searching and cant Figure out how to search in specific areas

but nice that’s what I thought but I wanted to double check. I’ll likely never use the PWR but that 2ND might come in handy

 

[BILT4ME]

I figured it was in the FAQ area someone else mentioned but I’m a bit of a boomer when it comes to searching and cant Figure out how to search in specific areas

but nice that’s what I thought but I wanted to double check. I’ll likely never use the PWR but that 2ND might come in handy

Easy on that Boomer s***, here Fetus........

 

[BILT4ME]

I figured it was in the FAQ area someone else mentioned but I’m a bit of a boomer when it comes to searching and cant Figure out how to search in specific areas

but nice that’s what I thought but I wanted to double check. I’ll likely never use the PWR but that 2ND might come in handy

I drive with PWR on all the time. I never use the 2nd because I like the tire spin.

Not using the PWR button is more like driving Grampa's Buick.

 

[AverageTanner]

99% of your questions can probably be found here: 80-series FAQ for General Info, Modification and Repairs

 

[graham5david]

Be aware that without the CDL engaged or in Low Range (locked CDL), you can lift ONE tire (or have one tire on slick mud or ice) and the truck will roll down hill or be stuck.

I have intentionally pulled the front of my truck onto a pile of snow in a parking lot to test this. As soon as one front tire was on the snow and I powered it a bit, it would spin and I went no where. If I stood on the throttle, it would inch forward because the viscous coupler would start to push it a little, but that WILL smoke a VC.

As soon as I shifted to Low Range to lock the CDL, I was able to move and push up into the snow and over the pile because now both front and rear axle would get power, not just one slipping wheel.

If you are on a steep driveway and jack up only one wheel, the truck WILL roll down the driveway unless chocked and/or the CDL is locked.

Been there. Nothing more terrifying then sliding down a steep snow covered road while strapped to another vehicle. I also learned to never try to get someone unstuck by pulling them uphill.

 

[flintknapper]

you don't get head snapping, tire spinning rage. That part is real if you floor it. In low range, from a dead stop on dry pavement, I can get a tire chirp in first, then when it shifts to 2nd, then to third in about 20 ft.

^^^^

Isn't that the truth! Any situation where you have relatively good traction.

In low range that one/two shift is brutal. It 'holds' first gear SO.....long you don't think it is ever going to shift to second. Then it does.....and it's pretty harsh if you've applied much throttle. I've actually developed a 'flinch' waiting for it.

 

[Pascoscout]

I too run with pwr on all the time. I like the shift points better that way. I rarely use the 2nd button.

 

[undecided]

I too run with pwr on all the time. I like the shift points better that way. I rarely use the 2nd button.

Huh, ill try it with it on tomorrow then

 

[Kat Man]

Been there. Nothing more terrifying then sliding down a steep snow covered road while strapped to another vehicle. I also learned to never try to get someone unstuck by pulling them uphill.

I have a 2001 LX 470 and after my kneee hitting the center diff lock for 20 years and trying to disengage I now need it as I have now built an over lander. but it won’t turn on now.

I hit the button right of the steering wheel and hear a relay click but now dash blinking or steady green light anymore. Checked fuse ok.

any ideas To get working? I know it’s not engaging because I don’t feel the steering getting stiff.
Also does The center diff lock in low range with or without actuator working? If this is the case then I can just use low range in those extreme conditions.

thanks everyone I am really enjoying my new hobby and this site.

 

[ppc]

I believe the early 100 series uses the same/similar transfer case to the 80 series which has a electrically operated CDL actuator. With the engine off, ignition turned on, in addition to hearing relays clicking if you crawl under the vehicle you should be able to hear the actuator operate for a short second or two. If you hear that, then most likely the problem is in the indicator sensor on the front side of the transfer case that controls the dash indicator light.

Also does The center diff lock in low range with or without actuator working

Your question doesn't make much sense. The actuator locks the center diff and is the only way to get it lock. I think your question is meant to ask "can low range be used without the center being locked?". The answer is yes but you won't have any addition traction beyond high range, just lower gears. That means if you have one wheel that spins the vehicle will not move. With the center locked then you can have one wheel spinning and still have power being sent to the wheels on the other axle. If you have one spinning wheel on each axle with the center locked then you are still stuck.

 

[Kat Man]

I believe the early 100 series uses the same/similar transfer case to the 80 series which has a electrically operated CDL actuator. With the engine off, ignition turned on, in addition to hearing relays clicking if you crawl under the vehicle you should be able to hear the actuator operate for a short second or two. If you hear that, then most likely the problem is in the indicator sensor on the front side of the transfer case that controls the dash indicator light.



Your question doesn't make much sense. The actuator locks the center diff and is the only way to get it lock. I think your question is meant to ask "can low range be used without the center being locked?". The answer is yes but you won't have any addition traction beyond high range, just lower gears. That means if you have one wheel that spins the vehicle will not move. With the center locked then you can have one wheel spinning and still have power being sent to the wheels on the other axle. If you have one spinning wheel on each axle with the center locked then you are still stuck.

Thanks for the troubleshooting tips. I think I tried to ask for too many answers and was not clear. Sounds like if my Diff Lock is not engaging while in High gear then putting it in Low range I still won’t have diff lock? According to this thread several times they mention that putting it in low gear automatically locks the CDL. That’s why I asked if this is true then I can live with no CDL in High Range and just use low for locking.

I will listen for the actuator sound underneath with ignition on engine off. But if it was just the indicator sensor and the CDL was actually engaging wouldn’t I feel the steering stiffness or resistance? I do not feel that typical stiff steering feel like when CDL worked and the light on the dash a steady green. So that would indicate no engagement and not just the indicator sensor?

 

[Kat Man]

Thanks for the troubleshooting tips. I think I tried to ask for too many answers and was not clear. Sounds like if my Diff Lock is not engaging while in High gear then putting it in Low range I still won’t have diff lock? According to this thread several times they mention that putting it in low gear automatically locks the CDL. That’s why I asked if this is true then I can live with no CDL in High Range and just use low for locking.

I will listen for the actuator sound underneath with ignition on engine off. But if it was just the indicator sensor and the CDL was actually engaging wouldn’t I feel the steering stiffness or resistance? I do not feel that typical stiff steering feel like when CDL worked and the light on the dash a steady green. So that would indicate no engagement and not just the indicator sensor?

Thanks for the troubleshooting tips. I think I tried to ask for too many answers and was not clear. Sounds like if my Diff Lock is not engaging while in High gear then putting it in Low range I still won’t have diff lock? According to this thread several times they mention that putting it in low gear automatically locks the CDL. That’s why I asked if this is true then I can live with no CDL in High Range and just use low for locking.

I will listen for the actuator sound underneath with ignition on engine off. But if it was just the indicator sensor and the CDL was actually engaging wouldn’t I feel the steering stiffness or resistance? I do not feel that typical stiff steering feel like when CDL worked and the light on the dash a steady green. So that would indicate no engagement and not just the indicator sensor?

Update. Thanks PPC I went underneath and the Actuator is working! So I hope that’s good news. But no green light and I feel nothing different with the steering like when everything was lit up.

 

[Rifleman]

Been there. Nothing more terrifying then sliding down a steep snow covered road while strapped to another vehicle. I also learned to never try to get someone unstuck by pulling them uphill.

This is a case were a little proper planning/rigging would come into play. If you're trying to winch another truck uphill while you're both sitting on snow. If at all possible, you should anchor the back end of you're truck to something solid, and unmovable like a tree. That way if you start to slide, a solid anchor point will keep both trucks from sliding down the hill.

 

[graham5david]

This is a case were a little proper planning/rigging would come into play. If you're trying to winch another truck uphill while you're both sitting on snow. If at all possible, you should anchor the back end of you're truck to something solid, and unmovable like a tree. That way if you start to slide, a solid anchor point will keep both trucks from sliding down the hill.

Thats what happens when you live your entire life in the west texas desert. Lol

 

[ppc]

Update. Thanks PPC I went underneath and the Actuator is working! So I hope that’s good news. But no green light and I feel nothing different with the steering like when everything was lit up.

In my opinion locking the CDL does not impact the steering as much as you are describing. Locking front and rear lockers definitely does. The dash indicator not lighting up may be influencing your perception.

At this point you should locate the switch/sensor on the front of the transfer case near the front driveshaft. Unplug the connector and short the two pins on the harness and that should light up the dash light. That will confirm that the light works, not a burned out bulb and the wiring is intact. Next would be to remove the indicate switch/sensor and bench test with a test light or multi-meter.

 

[Kat Man]

In my opinion locking the CDL does not impact the steering as much as you are describing. Locking front and rear lockers definitely does. The dash indicator not lighting up may be influencing your perception.

At this point you should locate the switch/sensor on the front of the transfer case near the front driveshaft. Unplug the connector and short the two pins on the harness and that should light up the dash light. That will confirm that the light works, not a burned out bulb and the wiring is intact. Next would be to remove the indicate switch/sensor and bench test with a test light or multi-meter.

I really appreciate the help your contribution to this site!

 

[Kat Man]

Hello Everybody - So thanks to the trouble advice from PPC and others I was able to determine the relay and actuator was working and so is the dash light and light switch when jumped. So I drop it off at Lexus and I get a nice low estimate of 500-700 for a fix. They thought it was a weak actuator solenoid. 3 days later it kicked their butt and they said it was internal in the TC and actually left the solenoid in and charged me 190.00. So before I accept I won’t have diff lock.....any ideas for further repair. Sounds like some spline or something won’t engage it. Therefore the dash light won’t go on and no locking.
also how much does this hurt my off road capabilities? I have ASR and Low Range

 

[baldilocks]

All you had to do was read more Mud horror stories of taking an 80 to the dealer for repairs and service work beyond an oil change and you could have saved yourself some grief and I’m not sure I’d trust them on an oil change. Those kids have never seen an engine that takes 8 quarts of oil. And they prove good for nothing mechanically but will re-flash the hell out of a PCM or key fob.

Without the CDL engaged you won’t go far off road without major difficulty. It’s highly doubtful the problem is inside the TC. If you can’t do it yourself, take it to a reputable Landcruiser shop even if it involves a few tanks of gas and a motel room

 

[flintknapper]

More often than not....when a CDL won't engage its from inactivity. These Tcases are pretty reliable and are certainly robust in build.

I'd try to find a spot off-road where you can drive around at low speeds and try to activate it under various conditions (NOT at rest).

Try under light throttle, try at low speed and let OFF the throttle and as it begins to coast, etc.

IF you can get it to engage (and disengage which could be an issue) then continued use....should make it better.

Good luck.