1998 SR5 & Limited Transfer Case swap - issues?

[farmerjon]

Two things:

1: My 98 SR5 j-shifter transfer case won't physically move all the way back into 4HI unless I force it really hard. Engages fine, works fine, no noises, and disengages fine. Will re-engage usually within a few minutes very easily. Feels like a hard limit halfway through the push from 2WD to 4HI.

I have done what the [MENTION=10169]TheDurk[/MENTION] suggested here - in terms of the first steps - so the tcase is fine - but seems weird to have such a hard block halfway through the shift from 2 to 4HI.
https://www.toyota-4runner.org/1824707-post2.html

2: I'm going to be moving my SR5 engine/transmission/j-shifter tcase to a 98 Limited. Any issues with the Limited shifter being replaced by the j-shifter? Do I need to swap the ECU or the entire computer or something, since the Limited shifter has a wire for the push button 4HI?
Update: seeing here that I likely just need to swap the 4WD position sensor on the tcase itself. Hoping that is the case - would appreciate clarification or further guidance.
Transfer case question (Swapping TO a j-shift from a pushbutton)

Thanks! Learning as I go. :cowboy:

 

[3bears]

not positive but I do think its a different ECU. The j shift is a mechanical t-case and if your limited is a push button, I believe that is more electrical controlled

 

[GhostRing]

not positive but I do think its a different ECU. The j shift is a mechanical t-case and if your limited is a push button, I believe that is more electrical controlled

I'm kind of in a similar situation, so I'm hoping it's easier to go less
complex than the other way around.

I have my '98 ltd and a '98 SR5 parts rig that I'm trying to
see if I can either make an EcoBox with both, or at least have
the J case on standby if the push-button case goes south.

 

[phattyduck]

2: I'm going to be moving my SR5 engine/transmission/j-shifter tcase to a 98 Limited. Any issues with the Limited shifter being replaced by the j-shifter? Do I need to swap the ECU or the entire computer or something, since the Limited shifter has a wire for the push button 4HI?

The Limited push-button case (even pre-multimode, like yours) has a small computer to run the 2-4 shifting. The j-shift case uses a simple relay to swap power to the ADD VSV's on the inner fender liner. The wiring will only be there for one of the two control methods in your dash... They are also on opposite sides of the truck (4WD ECU is in the driver's footwell, ADD relay is in the passenger footwell) There is a chance you can fool your 4WD ECU into thinking it is doing what it is supposed to be doing while only controlling the ADD VSV (and not the shift actuator), but you would have to look closely at the diagrams to see.

-Charlie

 

[farmerjon]

The Limited push-button case (even pre-multimode, like yours) has a small computer to run the 2-4 shifting. The j-shift case uses a simple relay to swap power to the ADD VSV's on the inner fender liner. The wiring will only be there for one of the two control methods in your dash... They are also on opposite sides of the truck (4WD ECU is in the driver's footwell, ADD relay is in the passenger footwell) There is a chance you can fool your 4WD ECU into thinking it is doing what it is supposed to be doing while only controlling the ADD VSV (and not the shift actuator), but you would have to look closely at the diagrams to see.

-Charlie

Sounds like I need to trace the wire that goes from the Limited push-button and see where it goes, whether that is the ECU, or the ADD relay.

If the 4WD ECU is separate from the main computer, I could move over the SR5 ECU and ignore the wire/leave it unplugged, and be fine? Since the ADD relay would still control the VSV?

 

[phattyduck]

Sounds like I need to trace the wire that goes from the Limited push-button and see where it goes, whether that is the ECU, or the ADD relay.

If the 4WD ECU is separate from the main computer, I could move over the SR5 ECU and ignore the wire/leave it unplugged, and be fine? Since the ADD relay would still control the VSV?

You sound very confused here.

The push-button 4WD system ('96-'98 Limited) has a 4WD ECU and no ADD relay.

The J-shift 4WD system ('96-'00 base and SR5) has an ADD relay and not 4WD ECU.

So, if there is a button on the shifter, it has a 4WD ECU and if not, it has the relay. The 4WD computer drives the actuator motor and reads the position sensors on that motor, then triggers the ADD VSVs. The ADD relay just triggers the ADD VSVs when it gets a signal from the 4WD switch on the transfer case.

-Charlie

 

[farmerjon]

You sound very confused here.

The push-button 4WD system ('96-'98 Limited) has a 4WD ECU and no ADD relay.

The J-shift 4WD system ('96-'00 base and SR5) has an ADD relay and not 4WD ECU.

So, if there is a button on the shifter, it has a 4WD ECU and if not, it has the relay. The 4WD computer drives the actuator motor and reads the position sensors on that motor, then triggers the ADD VSVs. The ADD relay just triggers the ADD VSVs when it gets a signal from the 4WD switch on the transfer case.

-Charlie

Thanks Charlie, I appreciate your patience and clarifications - I was indeed confused. This post I found earlier suggests no computer swap needed, but I wonder if it is just using a different switch/wiring harness.

Your second explanation makes sense that there is no 4WD ECU on the non-Limited. I do see an actuator on the back of my Limited tcase.

Transfer case question (Swapping TO a j-shift from a pushbutton)

It sounds like I won't know for sure what I'm doing until I'm in there - as I will either need to move over the ADD relay, or it'll "just work" with switching the plug as the link talks about, perhaps?

 

[phattyduck]

Thanks Charlie, I appreciate your patience and clarifications - I was indeed confused. This post I found earlier suggests no computer swap needed, but I wonder if it is just using a different switch/wiring harness.

Your second explanation makes sense that there is no 4WD ECU on the non-Limited. I do see an actuator on the back of my Limited tcase.

Transfer case question (Swapping TO a j-shift from a pushbutton)

It sounds like I won't know for sure what I'm doing until I'm in there - as I will either need to move over the ADD relay, or it'll "just work" with switching the plug as the link talks about, perhaps?

You are probably going to have to do a bit more than just one connector, but it can probably be done. I don't want to say 100% though, since I haven't done it. (but I do have a '97 j-shift in my '99 that was originally 2WD, so...)

-Charlie

 

[TheDurk]

not positive but I do think its a different ECU. The j shift is a mechanical t-case and if your limited is a push button, I believe that is more electrical controlled

ECU not involved. It is a separate module in the left kick panel which you can just disconnect from the T-case and forget about. You would probably need a 4WD relay box (which is normally in the RIGHT kick panel) to control the VSV vacuum valves which you would connect to the T-case sensor. I would post the wiring diagram but I am out of the country and it's all on my home computer. It's fairly simple as such things go. Going the other direction would be a serious pain, but doable.

 

[St Runner]

I put a j-shift on my 2001. In laymens terms only one of the pugs on your transmission harness is going to fit. Plug it in and your good to go. Making the 4WD lights on the dash work properly is more complex. Since I also deleted the ABS i just pulled the 4WD light bulbs out along with the traction control lights So my truck does not give me warnings and tell me what to do but I already have a ring on my finger for that

 

[farmerjon]

I put a j-shift on my 2001. In laymens terms only one of the pugs on your transmission harness is going to fit. Plug it in and your good to go. Making the 4WD lights on the dash work properly is more complex. Since I also deleted the ABS i just pulled the 4WD light bulbs out along with the traction control lights So my truck does not give me warnings and tell me what to do but I already have a ring on my finger for that

Given it is a 1998 with no TRAC - wondering if I can still just have the 4WD light work, or are you saying that they won't work because I need another plug to get the lights to work via the ECU?

 

[farmerjon]

ECU not involved. It is a separate module in the left kick panel which you can just disconnect from the T-case and forget about. You would probably need a 4WD relay box (which is normally in the RIGHT kick panel) to control the VSV vacuum valves which you would connect to the T-case sensor. I would post the wiring diagram but I am out of the country and it's all on my home computer. It's fairly simple as such things go. Going the other direction would be a serious pain, but doable.

I posted a new question about swapping over the ECU and the wiring harness - wondering if I can kind of avoid all of this if I do that?

98 SR5 Engine into a Limited Chassis - which wiring harness/ECU to use?