Topic: Transfer Case Repair Question

[wrenchtech]

I recently aquired a 23 spline transfer case out of a '87 turbo. It's a forward shifted unit. I noticed that the shift rail for the 2wd/4wd side of the unit is cracked right where the notch for 4wd lamp switch is. It feels like its still pretty solid, but of course it would break once I assembled it to the transmission and tried to run it  . I read the 4x4wire tech articles:   Convert a Forward-Shift Transfer Case to Top-Shift and   Twin Stick Shifter Install and I'm thinking I should be able to open the block-off plate for the non-existant top shifter and get in there to knock out the roll pin that holds the rail in and replace it with one out of the t-case that is coming out of my 1984 p/u (or order one from Marlin), but I'm hoping to avoid tearing down whole unit.

Also, the input shaft and the counter shaft seem to have a lot of endplay, eg. I can move them both in and out about an eighth of an inch (1/8") at the transmission face of the t-case. Is this is normal? -- Matt 

[BigMike]

I'm thinking I should be able to open the block-off plate for the non-existant top shifter and get in there to knock out the roll pin that holds the rail in and replace it with one out of the t-case that is coming out of my 1984 p/u

Yes, that will work but it will only work with the Low/High fork -- drivers side -- and it will not work for the 2WD/4WD fork because the fork that controls the 2WD/4WD shift hub is located in the 2nd-3rd housing area and can not be accessed from the top plate. You will have to remove the back 2 covers to get to that fork...

So here's what you need to do, and its very simple:
1) Remove the rear output flange, 30mm bolt and pull the flange off the shaft.
2) Remove the 10 14mm bolts from the 3rd housing as shown here:

3) Housings 3 and 4 will come off together in one single move. There are a couple areas where you can safely tap on the 3rd housing to help split it apart. In the above picture look at about 4:30 o'clock, 7 o'clock, and 9:30.
4) Now shift the t/case into 2WD/HI to push the shift fork out the back where you can get a punch on the roll pin and tap it out.
5) Remove the passenger's side 6mm allen bolt that is at the top of the t/case on housing 2 just past the top shift block off plate on the side. This retains the shift detent ball and spring. Remove the bolt and carefully catch the spring and the detent ball.
6) Now the rod will slide right out and its yours. Slide the new rod back in and put it back together. If you old gasket looks good then use it. DO NOT put silicone over the gasket, it will leak for sure. Either remove the gasket and use straight silicone (I recommend Toyota Black or Ultra Gray and I recommend against blue and orange silicone), or get a new gasket. Either way make sure you use some brake or carb spray on the surface to clean up and oil residues before putting the new gasket or silicone on.

It's really not that hard and I could do it in under 2 mins.

Also, the input shaft and the counter shaft seem to have a lot of endplay, eg. I can move them both in and out about an eighth of an inch (1/8") at the transmission face of the t-case. Is this is normal?

Yes, this is normal. There is nothing retaining the input and counter inside of the t/case. What happanes is that when you put the t/case behind the trans, the snap rings on the two front bearings (6307N Input and 63-32N Counter) is held in place by the grooves on the tail housing of the transmission.

It is important however that before you install your t/case, to make sure that both bearings are correctly seated against the reduction housing of the t/case. All 84+ t/case gear sets have a unique design and must be resting flush against the front of the t/case before installing behind the trans. If they to not sit flush, then turn the input with one hand, and apply pressure on the gear into the t/case with the other hand until they both fall into place against the reduction housing.

Regards,
BigMike

[Weldo]

Is there any real advantage on using a top shift configuration vs. the forward shift?  Is it just for fitment reasons?  Sorry for the hi-jack.

[wrenchtech [OP]]

Big Mike,

You're the man! When you describe it the work sounds easy.  I'll give it a try, and hopefully I'll become an expert myself, one day. Thanks

Weldo,

Mainly, it has to do with how your vehicle was equipped from the factory. If your transmission extension housing doesn't have the shifter mounted on it then it will have to be mounted on the t-case as a top shifter. I think Toyota had the shifters in different positions to accomodate stuff in the cab, like the center console on the SR5. -- Matt

[BigMike]

That's correct. Toyota first started using forward shifting t/cases in 1984. This is because of a new style transmission (the G-series) which is about 4 inches longer then the predecessor (the L-series). So to get the shift handle for the t/case closer to the trans shifter, they designed forward shifting rods in the '84 t/case.

Then in '85 the EFI was available and now we had the SR5 class and the basic Carb class. The carb trucks came with Bench seats and the SR5 EFI trucks came with buckets. So with the bench seat configuration, the shifter needed to be kept as far forward as possible incase short people drive the truck and need to pull the seat all the way forward. But on the SR5 models, having the bucket seats allowed for a closer placement of the t/case shift lever to the driver, so the Top shift tcase was used.

So that meant that Toyota had to make two different cab designs, one that had a large elongated hole for both the transmission and transfercase handles (carb/bench seat model) and another cab with two holes, one for the trans and one for the t/case shifter (SR5 bucket model).

So in '89 Toyota finally had enough of the two cab designs and just went with one cab design. So all 89+ 4cyl (all EFI) trucks used forward shifting tcases which happened to be in the same location as the V6 model that used a different transfercase.

BigMike

[Weldo]

I see, thanks a lot fellas!  I love this site, I learn something new everyday!  So if I ever went to bucket seats (God willing I shall someday...) I could convert to a top shift T-case for more convenient shifting?  Also, when converting to top shift, can a twin stick be installed in the same manner as in a forward shift?

[wrenchtech [OP]]

It is important however that before you install your t/case, to make sure that both bearings are correctly seated against the reduction housing of the t/case. All 84+ t/case gear sets have a unique design and must be resting flush against the front of the t/case before installing behind the trans. If they to not sit flush, then turn the input with one hand, and apply pressure on the gear into the t/case with the other hand until they both fall into place against the reduction housing.

The counter gear bearing was sticking out about 3/16"; I turned the input about 3/4's of a turn and the counter dropped right in to place

Now I'm thinking about the bolts that hold the t-case to the transmission. The trans and the t-case shipped to me separately and the bolts didn't come with them. I have another bolt that has the right diameter (10mm) and the right pitch. Can I use a common, unclassified, hex head bolt, that I might find at the local hardware store? And maybe some type of washer? -- Matt

[wrenchtech [OP]]

Well, I never fixed that shifter rail before installing it and now it has come apart on the vehicle. Can I pull off the crossmember, lower the transfer case and pull the rear covers off to get to that 2wd-4wd rail to replace it without having to remove the transfercase from the vehicle? Big Mike, I hope you're seeing this   -- Matt

[BigMike]

Well, since it's a forward shift unit, unfortunately for this case, the only way for either shift rod to come out, would be out the front of the transfercase, since that is where the rod has the fingers needed to catch onto the end of the shifter.

Pulling the rear housings 3 and 4 as described by the above picture, will give you access to the 2WD/4WD shift fork, which could then be removed using a punch to remove the roll pin, and then, following step #5 in my original post to remove the shift spring and detent ball, then the rod is free.........

............but the problem is that it is free to be removed from the FRONT of the case

You have no choice but to seperate the transfercase from the transmission tail housing. There is no way around this, unless you crack and break the front reduction housing of the transmission.

I suppose you could take the t/case shift base off of the transmission trail housing, and using a small die grinder (1") or a plasma cutter with a steady hand, you could cut off the front of the 4WD/2WD shift rod making sure that the cut maintains the same OD as the rest of the rod or smaller, and then you could pull the rod out the back of the t/case, and with the fingers of the rod being cut freely from the front of it, then you could retrieve the finger part out from the tail housing of the transmission, and that is how you could remove a forward shift rod without seperating the front t/case reduction housing from the trans tail housing.

But then you would have no way to install the new shift rod into the transfercase unless you cut the transmission tailhousing in half or something, rendering the transmission useless.




----> BigMike

[wrenchtech [OP]]

Transfer case out of the rig then     I imagine I'll have to tilt the motor,  transmission and transfer case down to get to the upper bolts.  I'll be doing it by myself with a transmission jack. Kinda hard to hold the t-case level with the jack because of its shape. Any tips on the best way to do that? -- Matt

[BigMike]

Hmmm........

Well, Im my opinion, I would not want to relay on a jack to catch the t/case, especially of its odd shape.

BigMike's Personal Transfercase Removal Procedure:
I would disconnect both drivelines from the t/case (don't need to remove them from the diffs), drain the t/case, remove the shifter, disconnect spd cable, unplug 4WD light plug, and then put the jack under the crossmember and give it some pressure up.

Then remove the 8 19mm bolts holding the crossmember to the frame, and also remove the 4 14mm bolts holding the t/case crossmember mount to the bottom of the t/case, and then slowly let the jack down....... all the way down until the crossmember and mount come free from the t/case. Keep an eye on the transmission shift handle as your are lowering the drivetrain down. If you have a chassis lowering kit (aka. "Body Lift") but did not also lengthen your tranny shifter, then I would be more concerned about it. You might need to remove the tranny shift knob and/or remove the whole trans shifter completely. I try to get away without having to remove it though. Shift the transmission into 3rd gear and hopefully it won't give you any trouble

Don't remove the mount from the crossmember, just remove the 14mm bolts connecting the mount to the bottom of the reduction housing of the t/case.

At this point, with the crossmember lowered and removed, and whole engine and drivetrain would be hanging down and held up only by the engine mounts and slight pressure from the exhaust system. This is ok as long as your exhaust system is healthy and you don't start doing pull-ups from the back of the t/case. Having it all hanging from the engine mounts for 30mins or so wouldn't be bad, but I would definitely jack it all back up to near stock height if I were to go to sleep or finish the job at a later time..

Then I would remove the 6 14mm bolts that connect the front of the t/case to the rear of the transmission -- but I would leave one of the upper 14mm bolts untouched until all of the other 5 bolts are completely removed. Remember, some t/case gear oil will be in the back section of the transmission tail housing, so expect about 10 ounces of gear oil to drain once the seal between the trans and t/case is broken. Put some rags under it or your drain pan.

Then I would slowly remove the last remaining bolt, and as the t/case begins to tilt down, it will apply more pressure on the input-coupler. Keeping one hand on the t/case, I would make sure it did not suprise me and just fall out on top of me.

FYI, in my experiences, I have never had a t/case just slip out and fall to the ground in this situation. But there is a first time for everything, so I would just keep a little bit of pressure on the t/case with my free hand while I remove the last 14mm bolt. The friction of the t/case input to transmission output coupler has always been enough to hold the t/case in one place without it falling to the earth.

After I remove the last 14mm bolt, then get all of the bolts and tools out of the way, and pull the t/case out from the back of the transmission.

If you kept the floor relatively clean or you don't mind getting a bit dirty, then I usually ditch the creeper at this point and just lay on my back. I can't stand having to control the creeper from rolling around while I am trying to pull out a freak'n transfercase
It shouldn't be too hard to do! Good luck!

[wrenchtech [OP]]

In the transfercase disassembly article on the main Marlin website they show what looks like a snapring on the bearing on the end of the idler shaft. Won't this prevent me from pulling housings 3 and 4 off in one move?

 

Nope, there is nothing holding that 4WD Idler gear on the #2 housing, so it can be removed along with the #3 housing without needing to remove that c-clip. So thats why its best to not seperate housings #4 and #3. If they are sealed now, then just leave it that way. It will all pull out in one move. The only catch is when you put it back together, it can *sometimes* be a PITA to get all of the gears aligned with the cage bearings. But just keep playing with it and you can get it to go back together.

And this must be the rail and fork in question, with the mystery mechanic driving out the roll pin.

   

As far as finding a new rail goes, can I scavenge the one from my spare forward shifted '84 t-case (which was behind a G52 trans) ? Thanks -- Matt

Yup, that is the fork that must be removed from the 2WD/4WD shift rod inorder for the shift rod to come out the front of the t/case.

Yes, all 84-88 Carburated 22R forward shift rods are the same as the forward shift rods found in any 86-87 Turbo 22R-TE 23-spline case.

Mike

[wrenchtech [OP]]

Man, it's been a while since I started this thread, but I finally made some progress. I cracked open a spare RF1A transfercase to get the shift rail I need to fix my turbo case. I just wanted to check in to get some feedback. I want to be come familiar with these units so I can learn to rebuild and upgrade them in the future and not just dissemble and trash them. I opened the case as BigMike advised (see picture below). Then I removed the 4wd switch, the detent ball and spring,  and then drove the roll pin out of the shift fork. Piece of cake!

Later I'll get a shift rail to fix the donor case so I can use it in the future.

Right now I want to get the case sections back together so I can store it safely. It looks simple enough but I have two questions. One of the oil pipes is loose and fell out and an extra ball fell out of somewhere (the smaller ball in the picture below) I think the FSM shows a ball related to the speedo gear, which I took off for a moment, but i didn't see it come out so I'm not sure where it came from. How hard is it to align the oil pipes to align back into their spots on the rear housing when putting the housing back together?

Also I noticed that there is a notch on the opposite side of the shift rail from the two that the detent ball rides on. Is that an interlock system that stops one rail from moving when the other rail is in a certain range of motion? Is it just a pin between the two rails or is there a spring or ball that I didn't notice on that side too? Thanks for the assistance. -- Matt

[wrenchtech [OP]]

Well it was a PITA to get the sections back together, but not too bad. It was lining up the oil pipes that presented the biggest challenge. With the help of the FSM I also figured out where those two extra balls came from and got them back in their rightful places. One of the balls was the speedo gear to output shaft holder and the other was for the spacer on the other side of the transfer drive gear. Fortunately the t/c I'm working on is an extra one I had lying around so it was a pretty low stress practice run, and I got the shift shaft I need to repair the t/c in my DD. Now I'm worried about getting my t/c apart from my tranny while they're in the vehicle, especially since I put them together with grey RTV    

The upside of all this is that I made my first trip into the guts of an RF1A t/c. My conclusion is that I'd feel comfortable trying to rebuild the whole enchilada or installing a set of crawler gears. Pretty soon I'll work my way up to rebilding W and R series trannys. -- Matt