Manually shift solenoid-actuated T-case

[aemravan]

I need someone to help me confirm I am completely out of my mind here and just need to move on to a move reasonable project/thing to do with my time..


The FJ T-case has become more and more of a swap in the recent years with folks having failing solenoids on their automatically actuated, full time 4wd t-cases.. I am one of those people. Currently running a twin-stick setup with a FJ t-case. Without getting into the reasons that got me to start thinking what I'm thinking.. the huge obvious plus to the factory cases we have is the differentiating aspect allowing the rig to run a full-time 4wd setup.

Last year coming back home from a camping trip in a partial blizzard condition I found myself second guessing the rig being in 4Hi on the highway as the slush started to become intermittent.. Obviously I going down the highway in a 6,000lb rig in slick condition you would prefer to have 4wd.. but with long runs of just wet asphault I started questioning how long I could go before getting myself into a bind (literally lol).

anyhow.. that got me thinking .. really.. the only issue driving everyone to the swap is a failed solenoid that no longer shifts the forks.. what if... just what if, someone rigged up a way to manually actuate the same 2 shift rods via a similar twin-stick setup from the cab..? I feel like this could be done rather easily with a straight-up jerry rigged under-car solution if you printed a case to go in place of the actuator with 2 plungers that could be attached to the factory shift works through a ball-detent setup for those folks that rarely use the diff lock and 4lo (would require literally getting under the rig and pulling/pushing each plunger). That's not an option for me.. but that got me thinking about coming up with some sort of a linkage system to run into the cab for ease of use..

Unfortunately me being the idiot I am I sold my perfectly working case for like $200 locally after doing the swap so doing any sort of R&D is going to be tough... so before I even continued to entertain the idea I wanted to be told to stop where I'm at :hiding:

 

[aemravan]

Maybe .. just maybe .. I’m not TOO crazy .. some quick research has landed me onto something I haven’t even considered … cable actuators ..

Sent from my iPhone using Tapatalk

 

[rdruss]

The cable idea probably makes the most sense as it would require less fabrication I think. So, refresh my memory, the AWD case like I have and you had, has two shift options: 4Lo and Center locking Diff. My 4Lo doesn't work but center diff lock does, so I'm not that concerned, I don't off road. So, there's two shift rods in the little black box on the back of my T-case that control those two positions. Could almost fit some kind of external control right to the back of this box and move the rods in/out.
I'll let you figure out how to do it most simply/reliably/durably.

 

[aemravan]

The cable idea probably makes the most sense as it would require less fabrication I think. So, refresh my memory, the AWD case like I have and you had, has two shift options: 4Lo and Center locking Diff. My 4Lo doesn't work but center diff lock does, so I'm not that concerned, I don't off road. So, there's two shift rods in the little black box on the back of my T-case that control those two positions. Could almost fit some kind of external control right to the back of this box and move the rods in/out.
I'll let you figure out how to do it most simply/reliably/durably.

that's exactly right. The two shift works already come out of the transfer case and into the actuator where they are gear-driven to move in/out. I think with the actuator box itself removed you would essentially be looking at a very similar setup to what you see in the above image.. that's a different case but very similar principal.. a couple of custom brackets to fasten to the t-case to secure the cables in place and some sort of a custom clevis to mount to the end of both of the shift rods to allow them to be tied to the cable actuator.

If I am not mistaking, the rods both have seals on them to keep gear oil out of the actuator so I THINK there is no concern with them being exposed, though I guess it wouldn't take much to 3d print some sort of a housing cover to keep elements out if needed.

Not to mention having a cable actuated shifter set would allow you to really seal up the cabin vs what you have to do with the FJ t-case installation and cutting of the floor board.. pulling a quick measurement inside of the cab I think I could fit an off-the-shelf twin stick setup fairly easily into the ash tray area..

my only concern is how easy/hard it would be for the cable actuator to move the 2 shift forks around.. I may need to source a factory t-case with a fried actuator locally to do some tinkering..

 

[MikeinNH67]

I've always wondered why the aftermarket realm hasn't built something like this for more vehicles. Actuator issues have been common for all the vehicles I've had that shift with a button or dial.

 

[aemravan]

no kidding on that.. especially considering the cost of the replacement of the solenoid on these things in particular.. who knows.. maybe I'll get something in the works.

I have a lead on a spare transfer case with a crapped out actuator locally from a member I sold my other t case to so maybe I can get something tested out sometime soon and see if this is feasible at all or not..

 

[4RunnerAquasport]

Interesting idea.
As far as why no one has come up with a fix or something similar to your idea is a good question.
Most owners of the 4th and 5th gens don't really off road and there are a lot of people that live in temperate climates, not having to worry about snow and ice. Most of these people never even engage the diff lock or 4Lo. So the demand might not be there to warrant the time spent for R&D. As the original and 2nd owners start selling these trucks off, there could be a demand in the future. Especially when the 5th gens start acting up.

If you printed an enclosure and fabbed up a gasket, then the shift rods and the cable ends should be protected from corrosion and last quite awhile. This would almost be a necessity considering what they would be exposed to by us off road delinquents, not to mention the chemically toxic assault they would endure in the snow belt.

I would even have some 3/8 fuel line or some heavy duty marine heat shrink over the exposed jacket of the cables to ensure they don't deteriorate as well.

If this could be done for under a $500 price point in parts, it might get some attention especially if it could be installed in a day or less, keeping the labor costs down. The OEM prices of $1000 for the actuator and $2500 for the case is ridiculous. There are a slew of actuators for sale online at a pretty wide price range, but not an easy install if I remember correctly.


I still have my OEM taking up space in the garage, if it will help in some way.
It was still operational.

 

[aemravan]

Interesting idea.
As far as why no one has come up with a fix or something similar to your idea is a good question.
Most owners of the 4th and 5th gens don't really off road and there are a lot of people that live in temperate climates, not having to worry about snow and ice. Most of these people never even engage the diff lock or 4Lo. So the demand might not be there to warrant the time spent for R&D. As the original and 2nd owners start selling these trucks off, there could be a demand in the future. Especially when the 5th gens start acting up.

If you printed an enclosure and fabbed up a gasket, then the shift rods and the cable ends should be protected from corrosion and last quite awhile. This would almost be a necessity considering what they would be exposed to by us off road delinquents, not to mention the chemically toxic assault they would endure in the snow belt.

I would even have some 3/8 fuel line or some heavy duty marine heat shrink over the exposed jacket of the cables to ensure they don't deteriorate as well.

If this could be done for under a $500 price point in parts, it might get some attention especially if it could be installed in a day or less, keeping the labor costs down. The OEM prices of $1000 for the actuator and $2500 for the case is ridiculous. There are a slew of actuators for sale online at a pretty wide price range, but not an easy install if I remember correctly.


I still have my OEM taking up space in the garage, if it will help in some way.
It was still operational.

All very solid points.. I'm looking at this through my personal experience which doesn't necessarily reflect the general market. The FJ transfer case has gained popularity, but I feel like it's still probably sub 50 vehicles nationwide rocking this solution in place of a failed actuator.

I think there's a really good chance to keep it at, or below, $500. Just judging by the pricing I am seeing on some already available shifters and cables that could be used as a starting point.

I think a printed cover wouldn't be an issue to make.. it should hold up decently since it technically shouldn't be exposed to much, if any, gear oil. Just as a protection to the shift rods not getting corroded.

The cables I wouldn't worry about protecting any further than they are.. it's not different than the transmission shift cable we already have and I have never seen or heard a cable failing due to exposure.

For oem unit you have in the garage, I'm assuming it's a complete diff? I'm trying to source one locally and may have a lead on a spare from the guy I sold mine to, but it north of 280k miles so if you have a fresher unit I may take you up on it if I'm ever down your way sometime in the near future.


For installation.. I feel like if this works it should be pretty straightforward.. though I've never taken apart the actuator.. I don't know if that can be removed to leave the shift rods exposed with the case still intact. If this could be done the rest should be straight forward.


I feel like another big challenge would be to retain the functional 4wd ecu functionality to keep the VSC and TRAC error codes off and operating as factory. I am thinking that if you retained the diff lock button and 4hi/lo switch it should just be a matter of placing a couple of position switch inputs to correspond to the shifter positions but I would have to do some investigating on that.. I don't know what would happen if the 4wd ecu would see the gear position change in the t-case without having sent the input signal to do so. Anyhow.. i'm rambling at this point.. but I think this is something i'll seriously start looking at shortly... it would be nice to get the factory full-time 4wd capability back into the rig..

 

[4RunnerAquasport]

How to retain the factory shift rods is a good question. I dug around a little and my first impression is that getting the actuator off the shift rod might be difficult.
I didn't realize you have to crack the case to remove the actuator for replacement.

 

[aemravan]

How to retain the factory shift rods is a good question. I dug around a little and my first impression is that getting the actuator off the shift rod might be difficult.
I didn't realize you have to crack the case to remove the actuator for replacement.

Yea, that's the part of tinkering I have yet to do.. the reason it needs to be cracked open to replace is because the new actuator obviously is assembled and timed with the gears to each rod. I am thinking for a failed solenoid it could possibly done without cracking the case by just opening up the solenoid to remove the gears. I have heard of a few guys doing a fix/replacement with the case still in the rig, but can't confirm until I have one to tinker with..

 

[rdruss]

Timmy the Toolman has a video where he fixes a T-Case actuator on vehicle that is pretty interesting and will answer some of your questions I think.