Can '91 5 speed manual trans & clutch be transplanted into 94 Previa w/auto trans?

[mountainhick]

Can '91 5 speed manual trans & clutch be transplanted into 94 Previa w/auto trans?

And, any particular installation/conversion troubles to expect?

[timsrv]

Yes, but I would highly recommend having the entire donor vehicle present during the swap. Aside from the actual transmission/clutch installation you will need to swap out the shifter & shift cables. You will also need to swap out the clutch pedal, clutch master cylinder, hydraulic clutch line, & the slave cylinder. Then there's the wire harness. At least in part you will need to swap out the dash harness and the engine/transmission harness. Manual Previas also have a starter relay instead of a neutral safety switch. The clutch safety switch will need to be rigged too & I'm guessing Toyota didn't weld the mount for it under the dash. You could just ignore the old shifting lever, but to make it professional I'd also swap the steering column or at the very least the parts that make them different.

In short, the job is possible but would be very time consuming. I'm thinking the ECUs are different, but I think you could continue to use the auto ECU. If you have an entire donor van available I'd probably swap that out to avoid potential unforeseen issues.

[mountainhick]

Thanks Tim. I have a lot of desire to do this, but that's more than bargained for!

If those manual transmission vans were just more common...

[timsrv]

There's a guy on the Yahoo Previa group (frankenvan I think) that took a 2wd automatic Previa with the dual sun-roofs, then converted it into a 5 speed manual transmission 4 wheel drive Previa. I didn't say "All-Trac" because he also replaced the transfer case with a 2 speed (high-low) transfer case from an 87-89 5 speed 4wd Toyota van. He also built & installed a 2" lift similar to the one I did HERE (http://www.toyotavantech.com/forum/showthread.php?3-Lifted-All-Trac-Previa).

Bottom line? Anything is possible. It all depends on how much time and money you are willing to invest in something. Tim

[mountainhick]

There's a guy on the Yahoo Previa group (frankenvan I think) that took a 2wd automatic Previa with the dual sun-roofs, then converted it into a 5 speed manual transmission 4 wheel drive Previa. I didn't say "All-Trac" because he also replaced the transfer case with a 2 speed (high-low) transfer case from an 87-89 5 speed 4wd Toyota van. He also built & installed a 2" lift similar to the one I did HERE (http://www.toyotavantech.com/forum/showthread.php?3-Lifted-All-Trac-Previa).

Bottom line? Anything is possible. It all depends on how much time and money you are willing to invest in something. Tim

Dayum!!! That right there IS MY DREAM!!!

[mountainhick]

Well now I've gone and done it.

So, this '94 auto is in great shape but really hasn't been cutting it here. First gear with the auto tranny is not geared low enough, and just climbing up our driveway here in the Coolorado mountains just about stalls it. Didn't used to happen with the '92 five speed, manual gearing is considerably lower in first.

I have been wanting a 5 speed manual again badly. I have been looking daily at craigslist nationwide for 5 speed Previas, a couple came and went in locations I couldn't quite swing traveling to at the time they were available. Well, yesterday, a funny thing happened. A 5 speed popped up on the local craigslist. I went to see it and as soon as I saw it i realized it was my old '92 that I sold in 2001! significantly more beat up and worn cosmetically, with considerably more miles, but driving up the mountain to bring it home the engine and tranny feel strong and just fine! I bought it back after 12 years for $1300. It was meant to happen, my baby came home!

It will be the donor. I will indeed swap the manual tranny into the '94. What have I gotten myself into???

And I have an extra van for parts including a good engine for the coming years!

Now if I can find one of those darn hi lo transfer cases!

I'll have to set up a place to do this work, so it will be a while to get the project going, but it is going to happen!!!

[timsrv]

That's an awesome story. Congrats & good luck with the transmission swap! Tim

[mountainhick]

Hey just a thought, anything else you would service/replace just as matter of course amidst this work since things will be seriously disassembled?

[timsrv]

You're going to have your hands full already, but I would recommend a new clutch, throw-out bearing, pressure plate, etc. Take a good look at the rear main engine seal and the transmission input shaft seal & surrounding areas. Replace one or both of these if you see ANY signs of leakage. Then there's the clutch master & slave cylinders. Replace if leaking..........of course these aren't as critical as neither will require you to remove the transmission if you change later. There's some other threads here where we've talked about this swap. If you haven't already, do a search. Here's a couple such threads: http://www.toyotavantech.com/forum/showthread.php?312-Alltrac-Previa-Transfer-Case-observations-(long), http://www.toyotavantech.com/forum/showthread.php?722-Toyota-Van-2-speed-Transfer-Swap-into-AWD-Previa. Tim

[mountainhick]

Thanks Tim,

Clutch was replaced in the last year/10K miles,so I think it'll be OK, but perhaps the throwout bearing, I'll have a look at the service records and see what i can figure out there. Will review those threads too.

[mountainhick]

Looks like I may have found a TV 4x4 transfer case. Has to be shipped though. Wondering what I'll have to do for a transfer case shifter or linkage?? I talked with CMH1129 who said he used his auto trans shifter on the steering columnn for the 2wd/4x4 hi/lo. I'd be OK with that but would prefer a floor shift.

Anyone have the service manual pages for the 86-89 TV transfer case and shifter?? What kind of linkage is on the TV transfer case?

Another concern, I'd like to keep actual miles/odometer reading on the van being built, but also want a tach, so have the option to swap instrument clusters or add a tach. Is it possible to monkey the donor van's odo to match the actual miles on the '94, or swap odos in the clusters?

Also wondering about the speedometer driven gear on the TV T-case

[timsrv]

Here's a link to a downloadable 87 factory service manual: https://drive.google.com/file/d/1q4u_5zlshRsVDv5v86CiukP7wOD7nKyF/view. The TF section deals with the transfer case. This TF case uses a cable linkage with a shifter mounted to the floor. It is just a 3 position lever on the case, so there are options here. With the correct actuator even an electric shift could be rigged up. To keep things simple though, it would likely be easiest to use a shift lever/mechanism & cable from an 87-89 van.

I haven't tried altering miles on a Previa Odometer yet, but I did it on my son's 94 Corolla when I transplanted a 4 speed ECU controlled auto transmission where his 3 speed old school auto used to be. I swapped in the odometer from the donor vehicle & rolled it back to match the miles on his old odometer. I don't remember all the details, but there were some plastic pegs that were melted (I assume to prevent tampering) but they weren't much of a deterrent. They may have just been there as a tamper indicator? Regardless, once I dealt with those I was able to open things up enough to position the numbers where I wanted. Since this odometer is of the same era I would assume the mechanism to be the same or very similar.

There may be a speedo cable extension to make it reach the TF case. Just study both & use what parts are necessary to make it all work. Have fun! Tim

[mountainhick]

Awesome info as always, thanks Tim!

[mountainhick]

Progress: It took several weeks but finally, the garage is cleaned out of 30 years of accumulated crap, I washed the floor yesterday and ready to pull in and crib up the vans today for the transplant.

I almost had all the major parts here, but opened the box with the transfer case this morning and they forgot to include the shifter and cable. I called them on it this morning, and will be on the way today.

Specific questions:

Gaskets: dealer or aftermarket/online?
FIPG material recommendations?

Neutral safety switch is almost gone on the clutch pedal. Is this part repairable, available/replaceable or should I just rig up a momentary switch on the dash? The other option may be somehow to use the auto shifter switch on the column, but if everything goes well, I'd rather get rid of that shift lever once the floor transfer shifter is installed.

Ben

[timsrv]

I like the Toyota FIPG stuff. The dealer will have it for around $10 per tube. The clutch switch is Toyota part #84520-20020 & should be available from Toyota for around $50. Tim

[mountainhick]

$50 for a friggin switch! Niggly parts add up...

I got a great deal, bought a million things for only a dollar each!

[timsrv]

Yeah, clutch switches are a gray area for aftermarket. Might be worth looking into. Maybe you'll get lucky and find one on the cheap. Toyota quality is important on some things, but on other things you pay a lot more to simply have it come in a red box that says "Toyota". Tim

[mountainhick]

Transmissions dropped yesterday. Long day!

Used TV transfer is working and will indeed mate to Previa transmission.

Need help locating part number. A seal on the transfer needs replacing. I found a search function online based on VIN, but I have no VIN for the case. Probably the same part regardless, but also don't know how to cross reference to aftermarket parts. I need to order a few other things from rock auto so would like to source there is possible. They show several variations. And wondering about brands vs cost and quality. Rock has Timken

Part is front output shaft seal for '87 4x4 hi low transfer case.

[timsrv]

The original Toyota part number for this seal was #90311-38026. Latest part number for it is #90311-37003. MSRP is $8.45. When it comes to seals & gaskets I prefer OEM. I hate leaks and consider the extra buck or 2 worth it for Toyota quality. I'm sure other manufacturers make good stuff too, just not sure who to trust. Good luck. Tim

[mountainhick]

Thanks Tim, great help. You know, I hate putting you to the task of ID'ing parts for me. Any chance you can teach me to fish rather than giving me the fish? I am sure there will be more I'll need to figure out.

[timsrv]

I get the original part numbers from Toyota's EPC (Electronic Parts Catalog), then I go to 1stToyotaParts.com (http://www.1sttoyotaparts.com/part_number_search.html?) & do a part number search. Their system automatically converts old numbers to new ones & shows MSRP vs their price. Other on-line discount Toyota parts sites work this way too, so if you have another you prefer, then use them. I'll PM you information on how to get the EPC. Tim