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View Full Version : Single speed to 2 speed transfer case swap



Cirrus
11-10-2013, 11:44 AM
I have been poking around through old posts trying to figure out all the options there are to add a high/lo transfer case to my automatic van. I saw that someone added a high/lo to their auto (didn't say how) and also that people have just changed everything over to manual. Anyone care to chime in with their thoughts on the merits of either or do I just wait and wait for a manual 4x4 van to come up for sale? It wont be long til my tranny goes as the shifting is pretty rough from 2nd to 3rd and it seems to have a tough time pressuring up upon first start up these days. Also, the front seal weeps a little every time I shut it down.
Thanks,
John

timsrv
11-10-2013, 02:02 PM
I went ahead and moved your post as it is 4wd specific. If you have a failing transmission, the time to make this mod is when you go in to replace/rebuild it. Swapping just the TC (Transfer Case) is a pretty basic project as compared to swapping a complete 5 speed manual transmission (no clutch or wire harness stuff to mess with). In order to do this you will need a 2 speed TC and the TC shift mechanism & cable out of a donor van. The only issue with interchanging TCs is the input shafts. Toyota uses different input shafts on their autos & manuals. The good news is you will already have the correct input shaft from your old TC, but you'll need to take both TCs apart to swap over the shafts. Once you have the automatic input shaft installed into your 2 speed TC it's just a simple bolt-up swap. Then there's the shifter & cable to install. Just mount/install it the same way it was in the donor van. Tim

Cirrus
11-13-2013, 08:23 PM
Thanks for the reply Tim, I put up a WTB post for one.

trestlehed
11-15-2013, 12:25 PM
Once you have the automatic input shaft installed into your 2 speed TC it's just a simple bolt-up swap. Then there's the shifter & cable to install. Just mount/install it the same way it was in the donor van. Tim

I'm going to have this done soon. Since my van is an Auto tranny, do I need to search around for the engine cover panel from a 5 speed van to accomodate the hi/lo shifter with the factory holes, or can I just cut/torch holes for the new hi/lo shifter & cable mounts into my existing engine cover panel?

timsrv
11-15-2013, 12:42 PM
Either way you go you'll need to modify. I haven't done this particular project, but I would think it's easier to add the TC shifter to the automatic engine cover than to swap out the automatic shifter to the 5-speed cover. Idealy you would want the 5-speed engine cover there as an example for hole locations and to get all the fasteners, grommets, clips or whatever. If you're just rigging the parts (no donor cover), it can still be done, just takes longer to figure stuff out & may require trips to the hardware store. Tim

trestlehed
11-16-2013, 12:33 PM
OK thanks Tim.

Anyone here with a 5 spd 4wd who can take a pic of their engine cover plate (with the carpet pulled back)
so I can have some kind of reference?

Thanks.

Cirrus
01-26-2014, 07:23 PM
Hi Tim and anybody else that would know,
Is this the the transfer case that us Auto 4x4's would need to switch over to Hi/Lo? They are rebuilt and come with a warranty.
http://www.carmonkeys.com/1988-TOYOTA-VAN-WAGON-Transfer-Case-Assembly-Manual-Transmission
Thanks,
John

timsrv
01-26-2014, 08:32 PM
Sounds like it. Of course like the listing says "This is not actual picture of this product". Looks like that site lists 2 transfer cases for our vans (one for manual and one for automatic). The 2 speed transfer cases were only offered with the manual transmissions. The odd thing is the automatic one is simpler (only 1 speed), but they want another $200 for that one.

So, assuming they have them tagged correctly and you actually get the 2 speed case, you will still need the shifter mechanism and the shift cables to make it work. Don't forget you'll also need to open up both transfer cases (your old and the new) so you can swap input shafts (auto and manual transmissions have different TF case spline counts). Tim

Cirrus
01-26-2014, 08:53 PM
Thanks for the quick reply Tim, well when I get some $'s scraped together I may give this a shot. I might just change the tranny at the same time too. They carry the manual tranny too, $740. Maybe I would just change the whole shooting match. Besides the needed controls, plastic console, etc, would this be a direct bolt in? Trestlehead, have you found a used one yet? You wanna be the first to go this route???? :lol:
Thanks again Tim,
John

timsrv
01-26-2014, 09:06 PM
Complete swap from auto to manual is a big job. Here's a quote from another thread:


Swapping in a manual transmission is possible, but it's a big job in itself. If you are going to do it anyhow it would save time to do it now, but considering all that's involved, you may wish to wait. The best way to make that swap is to have a 5 speed donor van to rob parts off of. In addition to the transmission, you will need shift cables, the gear shift mount bracket and shift mechanisms. Then there's the clutch pedal with associated linkage, the clutch master cylinder and the slave cylinder. You will also need all the hydraulic plumbing, the flywheel, pressure plate, pilot bearing, throw-out bearing, clutch fork, etc. And don't forget the wire harness under the dash and in the engine compartment is different as well. Then there's the clutch safety switch and vans that weren't originally equipped with manual transmissions don't even have the mounting bracket for that under the dash. There is also the starter relay mounted in the engine compartment (manual transmissions have them, automatics don't) Then of course there will be the need for different drive shafts (both front and rear) because manual transmissions have a different length than automatics do.

Is a manual transmission swap possible? Yes it is. Is it time consuming and labor intensive? Yes it is. Is it worth it? That depends. If you pay a reputable mechanic to do the job, probably not. If you have the aptitude and desire to do yourself, then it can be a rewarding project. I have toyed with the idea myself and I will most likely do it someday. I have everything I need except the time. Even if I had the time, I wouldn't dream of tackling a job like this without a donor van, so I'd recommend you find one of those 1st, clear your plate of other projects, then tackle this mod.

FWIW, this has been done before by at least one person that I know of. A good alternative to an all-out transmission swap would be to swap your transfer case only with a 2 speed t-case from a 5 speed van. This is a pretty straight forward swap and won't take nearly the time or effort of a complete transmission change-over. Good luck with your project and please report back with your progress. If possible, please take lots of pics and post them here. Tim

trestlehed
01-26-2014, 10:32 PM
Maybe I would just change the whole shooting match. Besides the needed controls, plastic console, etc, would this be a direct bolt in? Trestlehead, have you found a used one yet? You wanna be the first to go this route???? :lol: John

Hi Cirrus, glad you didn't sell your van.
I bought the transfer case, cables, shifter and busted -up console all together from a TVT member from Colorado.
I haven't had time to deal with it yet, as I just got my van back after 6 months of rebuilding by a friend. And I just discovered I have now developed the dreaded power steering leak (even right after the top o-ring was just replaced). If I have the transfer case swap done, I'll post about it in the future.

My PS leak looks like it's coming from the fitting that sits on the flat metal band piece which bolts into the PS pump
on either side:

1288 1289

timsrv
01-26-2014, 10:48 PM
My PS leak looks like it's coming from the fitting that sits on the flat metal band piece which bolts into the PS pump
on either side:

It looks to me like it's coming from between the rubber hose & the nipple. A leak at the o-ring won't get on top of that plate, nor is there any way it could leak between the plate and the nipple. If the clamp is loose, tighten it. If it's tight, loosen it up, reposition, and tighten again.

FWIW, the spring steel clamps actually work better as there's no flat spot & they will self tighten over time as the hose compresses. Next to the spring steel clamps are the smaller width stainless adjustable clamps. The flat spot is smaller & they put more pressure psi on the rubber (due to less surface area). Tim

Cirrus
01-26-2014, 11:00 PM
Congratulations on both the acquisition of the Hi/Lo and getting your van back on the road Trestlehead!!!!
Yeah, in the end I could not part with the van.....
It would be great to see your van. PM me sometime and lets meet up for a coffee. Any other TVT'ers in SD should chime in too. We could have a meetup somewhere and then cruise the PCH!
John

trestlehed
01-27-2014, 09:53 AM
It looks to me like it's coming from between the rubber hose & the nipple. A leak at the o-ring won't get on top of that plate, nor is there any way it could leak between the plate and the nipple. Tim

Yep, that's what I thought. But I wasn't sure if the nipple assembly was one piece or not. I loosened the hose clamp,
moved it around a bit and re-tightened. It felt like the screw would stop at a certain point and not tighten any more.
I'll try another hose clamp. Can I get the spring type from any auto parts store?

trestlehed
01-27-2014, 09:58 AM
Congratulations on both the acquisition of the Hi/Lo and getting your van back on the road Trestlehead!!!!
Yeah, in the end I could not part with the van.....
It would be great to see your van. PM me sometime and lets meet up for a coffee. Any other TVT'ers in SD should chime in too. We could have a meetup somewhere and then cruise the PCH!
John

Yeah, that would be fun. We could form a self-help van group (like AA), and all swap stories about how much $
we have dumped into these things.:wnk:

Come to think of it, that's what this website is for!:clap:

timsrv
01-27-2014, 10:18 AM
Can I get the spring type from any auto parts store?

Usually. The problem with spring type is they need to be very size specific (limited range). When it's expanded to max it should just barely fit over hose. Also they don't work too good if the hose is old, brittle, or stiff. If the hose already has a "memory" from the old clamp, you'll need to slice off a little and re-seat. For these reasons the spring type won't always work, so the next best thing is the narrow stainless type. Tim

outlawmws
02-16-2019, 11:15 AM
Resurrecting this thread with a question: It seems most of the Toy Transfer cases are similar for use across product lines. Am I right?

So could I get an 85-89 hi/lo Transfer case from an "other Toyota" (Truck/rave 4 etc) with an Auto, and bolt it in place of the single speed??

I would still need linkage and such, but the main job should be bolt in (and more common)

originalkwyjibo
02-17-2019, 01:07 AM
I have been wanting to explore this option as well but just haven't had the time. First of all no, it is not a bolt in proposition. The trucks and 4runners have a right side t-case output while the vans are left. Looking at some parts diagram and reading some threads on the now defunct yotavans.org it appears internals may be interchangeable. Unfortunately theory is as far as I have gotten on this.

outlawmws
02-17-2019, 10:10 AM
Well that seems counter-intuitive. I'd seen some ads for right hand, and was hoping those were anomalies. dang... Thanks for the heads up. This is my first fray into Toyota so still learning nuances...

Doxy
06-21-2023, 05:06 AM
My van is factory auto with HI/LOW tc. I understand you didnt get the diesel 4x4 versions of these vans in America so maybe it wasn't a option in the petrol ones? Anycase it should be possible to find a hi low auto tc that bolts in

outlawmws
06-21-2023, 05:40 PM
My van is factory auto with HI/LOW tc. I understand you didnt get the diesel 4x4 versions of these vans in America so maybe it wasn't a option in the petrol ones? Anycase it should be possible to find a hi low auto tc that bolts in


I've done more research and the input shaft is o different splines. - I'm told you can swap the auto input to the hi/lo and then its a bolt in, other than the linkage.

originalkwyjibo
06-22-2023, 02:27 AM
The input is different spline and different length. It requires a near complete teardown of the transfercase but there really isn't anything complex to the job and yes, once it's swapped the t-case bolts right in. This is how I did mine.