Possibility of 2 Low and more...

Wahugg

Original poster
Member
Dec 4, 2011
87
Hello all,

I have been pondering this for a while and finally my curiosity has gotten the better of me and I wish to attempt it. I actually have two ideas that I have been kicking around. The first is 2Low and the other is a locked front end but still being able to retain use of it on pavement by unlocking it.

The problems;

There is no pre-existing selection for 2x4 low. After reading the theory of operation over on ORTB I'm not even sure I am even going to be able to manipulate the TC to only engage the rear output shaft.

As for the locker, there is only one option for us. It's a Lock-Right and it is always locked under power. With out any power being sent to the front drive shaft, it simply acts like an open carrier. Off-road this is great because now all four wheels are locked to each other, but on pavement you lost any hope of using 4x4 again. The front wheels won't be able to spin at different speeds required when making a turn, so major under-steer will be present plus major binding and things WILL break. I want to still be able to retain 4x4 on pavement.

The Solutions?

The only way I can see achieving at least the 4x4 on pavement is by manipulating the Front Actuator. Under normal 4x4 operation, it connects the front intermediate shaft with the passenger CV shaft to deliver power to it. Well if I could some how send a command to disengage the actuator, the passenger wheel is now no longer able to receive power. It is able to turn by its self, free of the drivers front wheel. In an open carrier this would totally nullify the 4x4 system, but with the locker, the drivers wheel would still receive power. So I would have a fully engaged 3x4 system. There still would be binding on pavement like normal, but now steering is possible with out the fear of something in the front blowing up. Sure things are going to be stressed, but moderation in everything right? That should solve my fully locked 4x4 problem for TEMPORARY use on pavement.

As for 2low, I don't think it can be achieved with a front locker. If I had an open diff, I would simply use the method stated above to disconnect the front actuator to nullify power going to the front wheels, but I think the front differential could potential be over worked if used for long periods of time. The only way this could work with a front locker is if I could somehow allow the shift detent lever to move the shift fork to the low range, with out engaging the clutch to connect the output shaft leading to the front.

My questions.

Does this sound plausible?

Does my reasoning seem sound?

Does anyone have any tech docs on how the front actuator receives commands or any ideas to over ride the stock commands?

The big question; does anyone know if it is possible to achieve 2 low in the TC by preventing the shift detent lever to engage the clutches, but still allowing it to move the shift fork?

Finally am I insane for thinking of even doing or trying this?

Any other comments or insight is welcome, but please try to keep it related to the topic to allow me to keep moving forward.

Thanks

-Wahugg
 

Wahugg

Original poster
Member
Dec 4, 2011
87
jham said:
SAS conversion would open up the options for a locker in the front just my thoughts

A locker is already available for the front; Lockright (Lock Right) lockers, Powertrax, best prices, lowest cost locker kits

Lockright part number 1935, we have the same 7.2 front diff as the S-10. I am not willing to do an SAS. That is to much time, money, and practicality/modification to put into this project in my opinion. My TB is a daily driver (over 80 mile commute a day) and living the life I do it is simply not plausible... But thanks for the suggestion! :thumbsup:

-Wahugg
 

jham

Member
Nov 20, 2011
1,334
Wahugg said:
A locker is already available for the front; Lockright (Lock Right) lockers, Powertrax, best prices, lowest cost locker kits

Lockright part number 1935, we have the same 7.2 front diff as the S-10. I am not willing to do an SAS. That is to much time, money, and practicality/modification to put into this project in my opinion. My TB is a daily driver (over 80 mile commute a day) and living the life I do it is simply not plausible... But thanks for the suggestion! :thumbsup:

-Wahugg

as your daily driver why would you need a locker up front then? :confused:
 

Wahugg

Original poster
Member
Dec 4, 2011
87
jham said:
as your daily driver why would you need a locker up front then? :confused:

I live on a farm where 4x4 is a very nice but not essential, and owning two trucks is not in my budget. But recently I have been spending more and more time out at our Cranberry Farm in Michigan. The ground consist of sand, and peat where true 4x4 is essential and at 280 acres, with most of it only 4 feet above sea level right next to a lake it is very, very wet and vast. I have to drive the 300mile trip, so practicality is BIG for me!! I also make monthly trips to visit the Texas farm which is probably over 1200 miles round trip. Plus when I am here in Ohio my daily commute is not practical with a SAS.

With what I hope to achieve, my MPG will not be affected and my 4x4 and towing capability on the farm will be greatly increased.

My daily life is basically off-roading, with some articulation. Not the major articulation others look for where an SAS is nice. My main goal is to take full advantage of all the traction I can get(locked front diff), as well as the low gearing on the pavement with out 4x4 (2low).

Plus having 4x4, or 3x4 in my case (if the plan does work) is great for on the pavement in Michigan and Ohio during the winter. This winter is pretty darn mild, but the winters especially in Michigan can get pretty gnarly. It's a nice thought that I'll still be able to use the 4x4 on pavement with out to much fear of blowing up the front with the locker installed.

I hope this clears my motives up.

-Wahugg
 

The_Roadie

Lifetime VIP Donor
Member
Nov 19, 2011
9,957
Portland, OR
Unless you get one front wheel up into the air a lot, the front locker won't help. If you're in soft terrain, and the tires are sinking in, then you're already getting as much traction as you can from the tires. Airing down can double your traction on many surfaces.

It's only if you totally lose traction on one front tire and all the torque is leaking out, that a front locker will help. And it puts your CV shaft/joints/disconnect at risk due to torque beyond what was designed into the parts.

I've been thinking about a 2LO mod to the TCCM for years. Not difficult, but there's not much of a market. I should just publish the circuit and have the users built it if they want.

2LO done mechanically inside the transfer case is not possible.
 

RayVoy

Member
Nov 20, 2011
939
I would just use an old fashion dash mounted switch to open the lead commanding the front actuator to operate.

The switch would probably need a second circuit to trick the TCCM into thinking the actuator was operated.
 

Boog2006

Member
Dec 3, 2011
151
I may be showing my extreme lack of knowledge with this question but...

Would the "auto" setting with a front locker not enable better turning?
 

RayVoy

Member
Nov 20, 2011
939
Boog2006 said:
Would the "auto" setting with a front locker not enable better turning?
Yes it would, but he wants to run in 2low (meaning switch is in the 4low position).
 

Boog2006

Member
Dec 3, 2011
151
So would roadie's 2lo mod be better suited for an "auto 2 lo"?

Or would there be too much risk of damage if the front end engaged?
 

RayVoy

Member
Nov 20, 2011
939
Boog2006 said:
So would roadie's 2lo mod be better suited for an "auto 2 lo"?
So, what your saying, is moving the switch to 4low, but have the TCCM control it like it does in the AUTO position.

My big fear, is that the auto engagement of front drive would place a tremendous strain on the internals of the t-case when it "banged" into engagement.

I guess, my opinion is that for the length of time anyone might need low, I don't see the value of not having the front pulling.
 

The_Roadie

Lifetime VIP Donor
Member
Nov 19, 2011
9,957
Portland, OR
Boog2006 said:
So would roadie's 2lo mod be better suited for an "auto 2 lo"?

Or would there be too much risk of damage if the front end engaged?
Way too much risk for offroading. I hate the very idea of A4WD. and A4LO would be a true abomination. :no:

RayVoy said:
I guess, my opinion is that for the length of time anyone might need low, I don't see the value of not having the front pulling.
Its benefit would only be seen when turning on tight uphill lumpy trails with intermittent loss of traction on one front wheel that would allow rotational momentum to build up on a tire in the air that might come down and catch, breaking front end parts in the deceleration. Or the function I need most often, pushing my trailer up the steep curved driveway where I need low range, but two tires worth of traction is enough, but when I'm in the curved part, the driveline binding in 4LO could damage the front end parts. Pretty rare set of circumstances.

nose2.jpg


nose3.jpg


nose4.jpg
 

RayVoy

Member
Nov 20, 2011
939
the roadie said:
Pretty rare set of circumstances.
Rare indeed; however, for every idea, there is a need.

Bill, I think you need a set of forward facing mirrors (or a periscope :rotfl:)
 

HARDTRAILZ

Moderator
Nov 18, 2011
49,665
My research of me adding a front locker revealed that a locked front and fully turning blows cv's apart. For me, I can't afford the loss of full steering so I am avoiding the locker.
 

fishsticks

Member
Nov 21, 2011
433
I guess I should chime in here, since I run the front locker.

What tire size do you hope to run? I beat the hell out of my locked front on 32s with zero problems. 35s and I started breaking stuff.

What are you running out back? G80? A real locker in an 8.6 or 9.5 will alleviate the need for 4wd altogether a lot of the time. I usually just run 2hi until I can't go any farther, then hit 4lo and continue on.

The front locker is worth it if you need all out traction. You just need to rethink how you use 4wd.

Also noteworthy. CVs will generally hold up unless you're at full lock and backing up. Reverse puts them in the bind situation that blows the outers. Even then I didn't start breaking them until the 35s went on.
 

Wahugg

Original poster
Member
Dec 4, 2011
87
Sorry for the lack of participation in this thread; unexpected matters arose and needed delt with but I'm back now.

Roadie, I understand where you are coming from when you say that the front diff lock may not be necessary if my wheels do not often leave the ground. But the reason why I am still looking at it as an option is I need every bit of traction I can get. If the right wheel falls in a softer section of peat or sand, and the left is still on the ground on more firm ground, the locker will greatly aid me. I have not thought of airing down out there. I will try that next month when I go back up to install the new frost monitoring system.

I was running an open diff in the rear. I was constantly getting stuck so I went over to the local junk yard and picked up a 03 8.0 G80 for only $200!! I didn't care that it was only the 8.0 sized diff, at that price and in the good condition it was in I snatched it right on up!

As far as 2low not being achievable in the Transfer-case, does that mean that the an unconnected spline disconnect is the only way to go then? If that is so, I would greatly appreciate help with the circuitry on that. I can solder just fine, but I tend to be limited when it comes to designing more advanced circuitry.

Thanks for all the responses!

-Wahugg
 

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