Topic: '87 2WD to 4WD Swap Questions

[CheapHeap]

Hello.  New member, but a long time Toyota driver / mechanic.  I have a 2WD in good shape I would like to do a 4WD swap on.  I have a R150f transmission with the electric actuator on the transfer case that I would like to use for the swap.  Is there any info out there on converting the t-case to a manually shifted unit?  I don't have e-locker axles, or the electronic control unit and really prefer the idea of a lever controlled unit, but haven't found anything helpful to see if converting it is possible.  Thanks for the read!

[redneckcustoms13]

Easiest option is sell the r150. Get a w56 and it bolts to your engine without the need of a very expensive bellhousing and tcase adapter/tcase input shaft.

[T-Revv]

Easiest option is sell the r150. Get a w56 and it bolts to your engine without the need of a very expensive bellhousing and tcase adapter/tcase input shaft.

I agree with this, with a 87 im going to assume you have a 22r/e, you would need an R151F bellhousing to bolt that up to your engine, which is going to be very hard to find and expensive. 

[CheapHeap [OP]]

OK.  Are there any other options?  Assuming I have a bellhousing to fit the motor to the transmission, anyone have any good information on eliminating the electrically actuated t-case and replacing it with a manually operated unit?  Has anyone here done it, and can it be done with existing parts?  Thanks again for the information!

[Lewis Hein]

I would guess the easiest route would be to wire the actuator to a switch in the dash. Get a wiring diagram for the truck the transmission came out of if you can and see which wire(s) get 12V to actuate the solenoid.

If you are unable to get a wiring diagram here is my PURE GUESS about how this solenoid MIGHT work:

I would GUESS that this is a chain-drive transfer case that was originally coupled to an automatic disconnecting differential? Maybe? If so, I would guess that there would be no need to shift between 4x4 and 2x4, as that was done at the front differential for those vehicles. (right?) So there are really only two motions the solenoid performs, I.E. shifting from high range to low range, and shifting back again. Therefore, there should only be two or at most three wires coming out of the thing.

If there are two wires, I ASSUME one would shift the case H-L when energized and the other L-H, while the solenoid grounds through the transmission. Verify the foregoing with a 12V battery.

If there are three wires, PERHAPS one of them is a ground wire. If the solenoid is good, you MAY be able to find the ground wire with a multimeter: For each wire, measure the resistance to the other two wires and add those two numbers together. A reasonable guess would be that the ground wire will be the one with the smallest number attached.
My reasoning is that If each "control" wire actuates a seperate coil inside of there, the circuit between it and ground should pass through exactly one coil. But to get to any other control wire, it will have to pass through exactly two coils, which means more resistance. (I'm making some assumptions here about the innards of the solenoid. said assumptions may be wrong!).

As a quick example, let's name the wires HL, LH and G. The coil that shifts high to low range has a resistance of 10 ohms and the coil that shifts low to high 5 ohms. Then the three values you get would be:
HL: 25
LH: 20
G: 15.
I just made these numbers up and they are purely arbitrary. Yours will be different but the principle holds.

If the above does not work, or one of the resistances is zero, or the solenoid has four or more wires attached, I am at a loss and you should not listen to me.

So once you have figured out which wire performs which shifting operation (eg high to low range or low to high range) when energized with 12V and appropriate ground connected (however that happens, see above) you can add some momentary switches in the dash to energize them and perform the H-L range and L-H range shift.

[Lewis Hein]

To answer your other question, Probably yes, you could put a lever actuated transfer case on the R150. Marlin Crawler makes adapters to  do this I think. But you would need to buy a different transfer case. If you get a good deal on a W56 transmission, snap it up. Otherwise try to find a R151 bell housing (not easy) and wire the solenoid per my above post.

[CheapHeap [OP]]

Thanks for the replies.  I don't want to use the e actuated t/case.  I appreciate all the input, but being that this is going in a 2WD to 4WD swapped truck, a manual shifted t/case makes the most sense to me.  I've been searching quite a bit, and from what I have read, any t/case will work - even a t/case off an auto or manual, although the case shift lever may need to be swapped or modified.  Whether it is a top shift or front shift, either could be used, but will require more work if the the t/case does not match the transmission.  Also, the spline count has to be checked but can also be changed.  I also saw that some t/cases have the front output on the left side and some are on the right, but either could be used.  I need a front output on the right side.  Early Trucks have gears, late Trucks and 4 Runners have chains, but some chain t/cases can be swapped to gears.  Anyway, I hope that is all correct info.  It is pretty awesome that Toyota made things the way they did - there is a vast amount of components that can be swapped and generally, they made things better over the years.  Thanks for the help.  If someone has a good deal on a t/case, please keep me in mind.