LC100/LX470 Part-Time Conversion Discussion (1 Viewer)

[mderrick]

you can spool with out hubs, this is like a early Tacoma, front end still spins but not under power, just by the tires via drive flanges.

You can have hubs with out the Spool, this requires the center diff to be locked and the hubs unlocked for 2WD. front driveline still spins but the tires are not powered since the hubs are unlocked. doughnut time, not torque steer, etc. no need to remove the driveline to get 2WD.

in the event of a front diff failure with hubs and with out a spool you will need to drop a driveline.

during the development of this kit i put 1000's of miles on my truck with hubs and a center diff while i got the t-case parts together for the spool, underdrive and low range gears.

top mod. full stop. I drive gnarly canyons all winter, my wife drives it also no problems.

@merbesfield PM me and we can have a phone conversation that can clear everything up for you, talk Tundras, 100's, and LV's....
@krispykritter where are you moving?

 

[krispykritter]

you can spool with out hubs, this is like a early Tacoma, front end still spins but not under power, just by the tires via drive flanges.

You can have hubs with out the Spool, this requires the center diff to be locked and the hubs unlocked for 2WD. front driveline still spins but the tires are not powered since the hubs are unlocked. doughnut time, not torque steer, etc. no need to remove the driveline to get 2WD.

in the event of a front diff failure with hubs and with out a spool you will need to drop a driveline.

during the development of this kit i put 1000's of miles on my truck with hubs and a center diff while i got the t-case parts together for the spool, underdrive and low range gears.

top mod. full stop. I drive gnarly canyons all winter, my wife drives it also no problems.

@merbesfield PM me and we can have a phone conversation that can clear everything up for you, talk Tundras, 100's, and LV's....
@krispykritter where are you moving?

Thanks for the clarification. I'm curious how the center diff/diff lock is constructed in these. Obviously a bit more complicated than your typical axle differential....unsurprisingly.

We're moving to the Denver area. Not entirely certain which portion yet, depends on where I end up working. Most likely opportunity is in the Westminster/Broomfield area. Florida is not good for the kinds of outdoors things we like to do.

 

[atnolan94]

Thinking about this, maybe my understanding is incorrect here, but spools normally lock both sides of a differential together.

It sounds like in this case, just installing the spool would make your center diff lock just engage or disengage the front driveshaft? So you could do the spool and leave the drive flanges in place and all that would happen is your front axle would be driven by the wheels rather than the t-case?

Yeah this is what I’m trying to explain, there’s no point in doing the hubs in my mind. If you do just the spool you have rwd and 4x4, but front driveline would always be engaged. The hubs unlocked allow your front driveline to not spin at all while in rwd.

If you just want to seal your hubs in the event that you break your diff, just get the @BenCC hub cover that’s made for this an probably 10% the cost of these hubs.

for what it’s worth this February when dallas got crushed with that freak ice storm, I never needed to put the cruiser in 4x4 and I got around problem free. I locked my hubs to allow me to use 4x4 but never needed it. My 2017 f250 on 37s couldn’t even move without engaging 4x4…

 

[atnolan94]

Thanks for the clarification. I'm curious how the center diff/diff lock is constructed in these. Obviously a bit more complicated than your typical axle differential....unsurprisingly.

We're moving to the Denver area. Not entirely certain which portion yet, depends on where I end up working. Most likely opportunity is in the Westminster/Broomfield area. Florida is not good for the kinds of outdoors things we like to do.

It’s actually not all that complicated, it’s a simple Open differential. The spool just eliminates the diff which provides drive to the front wheel. However the functionality of the CDL is maintained and will send equal drive to front and rear drive lines when engaged. Mr T was smart designing these T cases.

I’m the top left of the second pic you can see the CDL assembly which the spool replaces.

 

[krispykritter]

Yeah this is what I’m trying to explain, there’s no point in doing the hubs in my mind. If you do just the spool you have rwd and 4x4, but front driveline would always be engaged. The hubs unlocked allow your front driveline to not spin at all while in rwd.

If you just want to seal your hubs in the event that you break your diff, just get the @BenCC hub cover that’s made for this an probably 10% the cost of these hubs.

for what it’s worth this February when dallas got crushed with that freak ice storm, I never needed to put the cruiser in 4x4 and I got around problem free. I locked my hubs to allow me to use 4x4 but never needed it. My 2017 f250 on 37s couldn’t even move without engaging 4x4…

I spent a fair bit of time driving in the snow this past winter and while I probably would've been fine in 2wd, even with AWD there were several semi-sketchy moments. Part of the reason I bought this thing in the first place is the AWD system. As much as most people love the part-time conversion, it's just not for me.

I'll look into the hub covers, but would still be interested in buying the standalone hubs.

It’s actually not all that complicated, it’s a simple Open differential. The spool just eliminates the diff which provides drive to the front wheel. However the functionality of the CDL is maintained and will send equal drive to front and rear drive lines when engaged. Mr T was smart designing these T cases.

I’m the top left of the second pic you can see the CDL assembly which the spool replaces.

That's awesome, thank you! I guess I had it in my mind that it worked like a locking rear diff, where the differential allows each wheel to spin at a different speed until the spool is installed, then they are locked together. With a center diff, using the same principle, installing the spool should permanently lock the front and rear driveshafts together. That's clearly not the case, so how I imagine the center diff lock works is obviously wrong.

So my new understanding is that removing the center diff leaves only the rear shaft engaged to the transmission. So then, what's the mechanism by which the CDL switch engages the front driveline?

I appreciate the education!

 

[flintknapper]

Has anyone installed the kit with aftermarket CV's?

The reason I ask is I have Cardone HD CV's currently and they fit VERY tight in new OEM drive flanges. I'd like to do the part time kit but fear I would not be able to engage (or disengage) the locking hubs. Unless the fit of the hubs is looser than OEM drive flanges (splines).

 

[atnolan94]

Has anyone installed the kit with aftermarket CV's?

The reason I ask is I have Cardone HD CV's currently and they fit VERY tight in new OEM drive flanges. I'd like to do the part time kit but fear I would not be able to engage (or disengage) the locking hubs. Unless the fit of the hubs is looser than OEM drive flanges (splines).

The hub engages in itself. The splines are always engaged on the CV and have a C clip installed like stock. If you can get the hubs on you’ll be fine.

 

[flintknapper]

The hub engages in itself. The splines are always engaged on the CV and have a C clip installed like stock. If you can get the hubs on you’ll be fine.

Gotcha. So it doesn't engage and disengage the CV splines, rather there is hub clutch. So that puts me back in the ballgame. Thanks,

 

[atnolan94]

Gotcha. So it doesn't engage and disengage the CV splines, rather there is hub clutch. So that puts me back in the ballgame. Thanks,

Exactly. I tried to find a pic but I can’t right now. The hub body slips over the CV and the cv is affixed with a clip. The hub body has a bearing between the splined portion for the cv and the body itself. The body is keyed, and there is a male key of the same pattern that is affixed the hub face. Turning the lock and unlock dial pushes the male key into our pulls it out of the hub body. It’s a pretty neat little piece. Very serviceable.

think of the hub body as a drive flange, and the face/dial just engages and disengages the drive flange.

 

[merbesfield]

It'll behave just like your 40 series. The spool gets rid of the center differential and the two choices (button) are locked (4wd) or unlocked (2wd/RWD). You can certainly keep the front hubs locked, as many people do all winter.

Ok so let me see if I understand this bc saying it’s like my 40 is not clear. With front hubs unlocked it is 2wd. If you want 4wd you have to get out, lock each wheel hub, then get in and push the center Dif lock button on the dash to actually engage the 4wd. If you then deselect the dashboard lock button you will be back in 2wd, but the hubs will still be locked. What is happening if you leave the wheel hubs locked as you mentioned? Are you causing wear and tear? Does it drive any different w the hubs still engaged, but Center dif button not pushed? Why would you have locking hubs if you could leave the hubs locked? Trying to understand the various options and configurations. Thx

 

[flintknapper]

Ok so let me see if I understand this bc saying it’s like my 40 is not clear. With front hubs unlocked it is 2wd. If you want 4wd you have to get out, lock each wheel hub, then get in and push the center Dif lock button on the dash to actually engage the 4wd. If you then deselect the dashboard lock button you will be back in 2wd, but the hubs will still be locked. What is happening if you leave the wheel hubs locked as you mentioned? Are you causing wear and tear? Does it drive any different w the hubs still engaged, but Center dif button not pushed? Why would you have locking hubs if you could leave the hubs locked? Trying to understand the various options and configurations. Thx

Unlocking the hubs simply lets the wheels 'free wheel' (just like a two wheel drive vehicle.

1. Hubs unlocked, Tcase unlocked....you are rear wheel drive (no drive train components in the front end moving (driveshaft, diff or hubs).

2. Locking the Tcase with hubs unlocked powers/turns the front driveshaft, differential and front axles BUT no power to wheels. Again two wheel drive.

3. Locking the hubs but leaving Tcase unlocked also has the everything in the front rotating BUT it is being driven by the tires and is NOT connected at the Tcase. Two wheel drive...BUT you can immediately shift to 4wd by engaging the CDL (locking the Tcase).

 

[flintknapper]

Exactly. I tried to find a pic but I can’t right now. The hub body slips over the CV and the cv is affixed with a clip. The hub body has a bearing between the splined portion for the cv and the body itself. The body is keyed, and there is a male key of the same pattern that is affixed the hub face. Turning the lock and unlock dial pushes the male key into our pulls it out of the hub body. It’s a pretty neat little piece. Very serviceable.

think of the hub body as a drive flange, and the face/dial just engages and disengages the drive flange.

Just never seen the 'guts' of an Aisin locking hub. I know how various Warn and Ford factory hubs work (been using those for 50 years) but wasn't familiar with the Aisin. Thanks.

 

[merbesfield]

Unlocking the hubs simply lets the wheels 'free wheel' (just like a two wheel drive vehicle.

1. Hubs unlocked, Tcase unlocked....you are rear wheel drive (no drive train components in the front end moving (driveshaft, diff or hubs).

2. Locking the Tcase with hubs unlocked powers/turns the front driveshaft, differential and front axles BUT no power to wheels. Again two wheel drive.

3. Locking the hubs but leaving Tcase unlocked also has the everything in the front rotating BUT it is being driven by the tires and is NOT connected at the Tcase. Two wheel drive...BUT you can immediately shift to 4wd by engaging the CDL (locking the Tcase).

Got it. Thanks for clarification. I think this may be a good option for me as I am 99.9% on road and rarely off.

Has anyone attempted a push button 4wd system like my Tundra? This may simply be the 3rd option you described above.

 

[flintknapper]

Got it. Thanks for clarification. I think this may be a good option for me as I am 99.9% on road and rarely off.

Has anyone attempted a push button 4wd system like my Tundra? This may simply be the 3rd option you described above.

My Wife DD's our LX and is on road most of the time. Occasionally need 4wd around the ranch....but use the 80 series for that mostly.

So in my case...going part time, hubs unlocked, Tcase unlocked and just being rear wheel drive would make good sense. IF we need 4wd just get out and lock the hubs and Tcase (just like all my old 4wds). If I live where it snowed in the Winter then full time 4wd (all wheel drive) would be great, but we don't need it very often. Last winter being the exception.

The only drawback I can see (for some folks under some conditions) is that going part time eliminates the ability of the system to send power in differing amounts (front and rear). After part time, when you lock the Tcase you will send equal amounts of power (at the same speed) front and rear. Not always the best depending on conditions, excellent in others.

 

[mderrick]

here is a great video of how the Aisin hubs function and how PT and FT 4WD work. the second also covers lockers, Limited slip, and traction control.

Hub function and parts

Part time/ full time explained.

 

[atnolan94]

here is a great video of how the Aisin hubs function and how PT and FT 4WD work. the second also covers lockers, Limited slip, and traction control.

Hub function and parts

Part time/ full time explained.

Thats exactly it, good info for those with questions.

 

[hoser]

Ok so let me see if I understand this bc saying it’s like my 40 is not clear. With front hubs unlocked it is 2wd. If you want 4wd you have to get out, lock each wheel hub, then get in and push the center Dif lock button on the dash to actually engage the 4wd. If you then deselect the dashboard lock button you will be back in 2wd, but the hubs will still be locked. What is happening if you leave the wheel hubs locked as you mentioned? Are you causing wear and tear? Does it drive any different w the hubs still engaged, but Center dif button not pushed? Why would you have locking hubs if you could leave the hubs locked? Trying to understand the various options and configurations. Thx

You can leave the hubs locked, the difference in feel will hardly be noticeable. There will added wear and tear on the front CV's and differential but it will be very minimal. Part time hubs can help with front end drive line vibrations and reducing "spewed" CV grease. Your 1st Gen Tundra does not have selectable hubs nor auto-lock hubs. The front components are turning all the time when in 2wd.

 

[zipdoa]

The only drawback I can see (for some folks under some conditions) is that going part time eliminates the ability of the system to send power in differing amounts (front and rear). After part time, when you lock the Tcase you will send equal amounts of power (at the same speed) front and rear. Not always the best depending on conditions, excellent in others.

I think the T-case on a 100-series is an open center - no viscous coupling like in the 80-series. So it just follows path of least resistance? Not actually torque biasing.

 

[flintknapper]

I think the T-case on a 100-series is an open center - no viscous coupling like in the 80-series. So it just follows path of least resistance? Not actually torque biasing.

Correct. My post (perhaps poorly worded) was simply meant to convey that with a part time kit....you have either 2wd or 4wd. With the conventional set up... power 'can' go to either the front or rear axles (or both in perfect conditions).

Although if a person wanted to....you can add a viscous coupler to a 100 series Tcase by swapping in the back half an H2FA and shortening the rear driveshaft about 3".

 

[zipdoa]

Correct. My post (perhaps poorly worded) was simply meant to convey that with a part time kit....you have either 2wd or 4wd. With the conventional set up... power 'can' go to either the front or rear axles (or both in perfect conditions).

Although if a person wanted to....you can add a viscous coupler to a 100 series Tcase by swapping in the back half an H2FA and shortening the rear driveshaft about 3".

Interesting, I was wondering if the HF2AV from an 80 was compatible in a 100, given the similarity of the drivetrains.

I'd be more interested in making a Torsen center diff from a GX470 work in a 100, far superior to a viscous coupling imo.