New to me VF1A Transfer Case

Afternoon Tacoma World Peeps,

So I purchased this off of E-Bay and will be installing it behind my R150F. Before I do that however, I want do as much preventative maintenance as I can before installing it. I don't know it's history unfortunately but it does look a bit worse for wear.

I'm hoping you folks can offer some suggestions and insights into what all I can or should do to it before installing. I've already got a few items on the list but I would wager I'm missing a few also. I never torn one of these down before so any advice is really appreciated.

Things I am for sure on doing:

-Block ports and clean external surfaces (check all threads etc)
-Replace shift lever seat w/ HD Marlin Crawler
-Mod for Twin Stick from Front Range Off-Road
-Replace shift lever base gasket (thing w/ 4 bolts)
-Install HD shift spring x2 Marlin Crawler
-Replace Input shaft seal
-Replace rear and forward drive flange seals
-Remove and clean VSS
-Fill w/ Redline Gear Oil

Things I am considering but require more research:

-Take apart case and clean/install fresh Toyota FIPG (each location held together w/ FIPG)
-Test VSS some how?
-Test 2wd and 4wd and neutral (with twin stick installed)
-Complete tear down (really just removing the external case from the internal components to clean out old oil stuff and seal everything. Not sure how scary/hard this is.

Thanks for any suggestions guys. Below are pictures of the T-case as it sits today (just arrived) Should be a fully manual unit from a 98 v6 MT 4x4.

 

Doesn't look that bad actually, sure its dirty but don't see any major leaks or anything.
the shifter hole being open makes me think dirt may have fallen inside, so I would do a few drains and refills with cheap oil before using the good stuff.. or ake it apart and clean it out. really just depends how clean it looks inside if its worth doing or not but if you have the time why not.. split the case, check the magnets, clean it up, seal it with RTV and call it a day.

 

Yeah it could have been a lot worse lol. It really isn't that bad but yeah I was worried about the same thing (Shift handle opening). Would like to find a walk through or guide (video even better) of it being done. Found one for the gear driven model only.

I've heard people having issue with the balls falling out and stuff. Maybe I will just remove the ball, shift spring and stuff before hand from the top. I wonder if the 98 version is much different then what is laid out in my 2003 FSM. Might see if I can find the page from an older manual and compare. I just don't want to get in over my head.

 

It really just depends, if not much is wrong its not that bad to open up and put back together. pull it apart slowly and take pictures is always helpful.
It is one of my least favorite things cause that gear oil in there always smells terrible, but the mechanical part isn't that bad.
All the J shift cases are pretty similar so it shouldn't be that different, unless the 2003 is a button actuated shifter, i forget which models had them.
If there was tape over the hole or a shifter on it, I'd feel better about a few flushes, but you probably have the best look through the shifter to see how much dirt or if any did get in there.

 

Hmm based on this diagram I will need to replace one of the plugs (front I think) with the L4 Position Sensor. This is because I have a rear locker? Not sure why the transfer case needs to be aware the locker is activated or the other way around... See the attached PDF with highlighted portion.

Can anyone confirm this?
@SafetyDang ?

 

Mine was already auto 4x4 with the rear locker and had the plugs on the transfer case.
from when I researched the rear locker it only "engages" when you are in 4LO, hence the 4 lo switch on the transfer case that tells the 4wd/locker ecu 4lo is active.
There is also the grey wire mod that lets you engage the locker anytime (basically you trick that ecu into thinking the 4lo switch is always active).

You already have the rear locker working I would assume without 4lo, since you are 2wd, so you probalby don't have to mess with it.
But if you want to install the 4wd ecu and wire it all up like factory, that is how it works on the 4x4 cars and locker is disabled until you shift to 4lo, normally anyways.

 

Hmm interesting. Yeah due to being a pre-runner the locker works in 2wd. But I am swapping to a 4x4 ecu I snagged off e-bay. Gonna have to look at the wiring diagrams for what gets pinned differently on that swap. Ah the research never ends. I am perfectly happy to not have everything factory. I wouldn't mind having the lights on the dash for 4x4 and already have one for the locker. Otherwise I don't care. Oh and my cruise has to work, but that's all to do with the clutch sensors at the pedal.

Gonna start with the gray wire mod thread again... it's been a while.

ECU - 2003 v6 MT 4x4

 

Figured out how to make the 4x4 light work on another forum. Putting it here so I don't lose it and maybe someone can get some use from it. Basically just grab a green wire from the elocker computer on the driver side kick panel and hook it to the position switch on the transfer case and ground the second wire from the switch. So that makes me happy. Won't be purchasing the L4 position sensor at this stage based on this information.

 

Yeah I was going to say I don't even remember a 4lo light on the dash so prob not worth the effort.
The 4x4 light I would want, and I think is also tied into the ADD so that is more important, nice work

 

Crap realized I posted these pics in the wrong thread (working at the time lol). So gonna post them here and delete the other post. Keep things together because in the end I will clean up, format and document everything to save the next guy a lot of work. All of this information is available on the inter-webs as that's where I found it. But I've spent more time researching then I will wrenching and while I enjoy it, not everyone does.

"Spent the last two evenings after dinner cleaning up the t-case. It actually came out really nice and is a pretty clean little unit. Will finally be able to take the shift lever retainer off and have a good look around. Chain should be right inside the drain plug also so I will pull those and take a gander. I have some Toyota red FIPG in route with the other seals and stuff from Toyota."

 

If you are not using a 4wd control computer (different from the 5-speed manual ECU that you have), then you don't need to add rewire anything extra to have your locker work in any 4wd (HI/LO). It is only used to safely engage your locker and 4wd.

 

Thanks dude appreciate it. Lots to learn but man is it a blast.

 

Finally took apart the transfer case this last weekend. It came apart wrong (big surprise, likely my fault) and so I will have to reconstruct the synchro keys and spring and get everything meshed up and working again. Bit annoying but nothing I shouldn't be able to handle. Otherwise the inside looks to be in great shape. Zero metal, bearings are super smooth and all looks well.

Waiting for all the items to complete my small renewal (seals, fresh FIPG, upgraded shift springs and hex head plugs from Marlin) Here are some pics so far:






Notice the heat marks on the closest shift fork? Not sure what that is about... ^^


Made the required mod to allow shifting the rails independently. Which means taking out the little pill and trimming the little tab off the shift rail above ^

You can see the small piece that gets removed. I used a air powered cut off tool. Took about 20 seconds

 

Sorry for my ignorance, what is the use of shifting the rails independently, haven't come across a thread about this before. Also assuming plans for this are dual case?

 

X2

 

Purpose of separating shift rails is to operate Hi/lo and 4wd/2wd independently.

I know this is from back in May, but I hope you ground both the horizontal and vertical planes of that shift rail. Assuming the VF1A rails are similar to my VF2A case, there's a little nub that sticks up vertically that may or may not catch on your shifters and prevent full engagement of low range. Hard to tell from your photo of the rail is it looks like we are seeing just the bottom. It got hung up for me, and I know several others who had to pull and split the case a 2nd time to grind more. It's a crappy thing to find out when it's all bolted up. I'll see if I can find a pic on my phone.

 

Hope this helps. See how that nub sticks up? Get rid of it.